PC87591E, PC87591S and PC87591L LPC Mobile Embedded Controllers
© 2004 National Semiconductor Corporation www.national.com
PRELIMINARY
March 2004
Revision 1.07
PC87591E, PC87591S and PC87591L
LPC Mobile Embedded Controllers
General Description
The National Semiconductor PC87591E, PC87591S and
PC87591L are highly integrated, embedded controllers with
an embedded-RISC core and integrated advanced func-
tions. These devices are targeted for a wide range of porta-
ble applications that use the Low Pin Count (LPC) interface.
The PC87591S is targeted for security applications and in-
cludes supporting hardware such as the Hardware Random
Number Generator. The PC8591L replaces the on-chip
flash with 4K of boot ROM for value solutions using shared
BIOS architecture. “PC87591x” refers to all the devices.
The PC87591x incorporates National’s CompactRISC
CR16B core (a high-performance 16-bit RISC processor),
on-chip flash (ROM for the PC87591L) and RAM memories,
systemsupportfunctionsandaBusInterfaceUnit(BIU)that
directly interfaces with optional external memory (such as
flash) and I/O devices.
System support functions include: WATCHDOG and other
timers, interrupt control, general-purpose I/O (GPIO) with
internal keyboard matrix scanning, PS/2®Interface,
ACCESS.bus®interface, high accuracy analog-to-digital
(ADC) and digital-to-analog converters (DAC) for battery
charging, system control, system health monitoring and an-
alog controls.
The PC87591x interfaces with the host via an LPC interface
that provides the host with access to the Keyboard and em-
bedded controller interface channels, integrated functions,
Real-Time Clock (RTC), BIOS firmware and security func-
tions.
Like members of National’s SuperI/O family, the PC87591x
is PC01 and ACPI compliant.
Outstanding Features
Host interface, based on Intel’s LPC Interface Specifi-
cation Revision 1.0, September 29th, 1997
PC01 Rev 1.0, and ACPI 2.0 compliant
16-bit RISC core, with 2 Mbyte address space, and
running at up to 20 MHz
Software and Hardware controlled clock throttling
Shared BIOS flash memory (internal and/or external)
Y2K-compliant RTC
84/117 GPIO ports (for 128-pin/176-pin packages)
with a variety of wake-up events
Extremely low current consumption in Idle mode
JTAG-based debugger interface
128-pin and 176-pin options, in LQFP package
(PC87591L is 176-pin only)
Block Diagram
Core Bus
Peripheral Bus
Bus
KBC + PM
Host I/F
RTC
Processing
Unit
RAM
External
BIU
CR16B Core
32.768 KHz
ICU
HFCG
PMC
ADC
ACB
GPIO WDG
FLASH or ROM
MIWU
Memory + I/O
MFT16
Timer +
Adapter
PS/2
I/F
(X2)
CLK DAC
(X2)
Memory
Debugger
I/F
Shared mem.
+ Security
LPC
I/F Serial
IRQ SMI
Functions
Internal Bus
CR Access
DMA
JTAG
KBSCAN +
ACM USART
Peripherals
LPC Bus I/F
I/F Functions
PWM
Reset &
Config
MSWC
Bridge
Controlled
Host
National Semiconductor is a registered trademark of National Semiconductor Corporation. All other brand or product names are trademarks or registered trademarks of their respective holders.
www.national.com 2 Revision1.07
Features (Continued)
PC87591E/S/L
Device-Specific Information
The following table compares features for the devices in the PC87591x family. The features listed below are a superset of
the PC87591x family.
Features
Processing Unit
CompactRISC CR16B 16-bit embedded RISC pro-
cessor core (the “core”)
2 Mbyte address space
Internal Memory
Up to 128 Kbytes of on-chip flash memory (4 Kbytes
of ROM in the PC87591L)
Supports BIOS (flash) memory sharing with PC host
On-chip flash is field upgradable by host, CR16B,
parallel interface or JTAG
Boot blocks for both CR16B and Host Code
Memory contents protection and security
Hardware-protected boot zone with block protection
circuit
2K (PC87591E/L) or 4K of on-chip RAM (PC87591S)
All memory types can hold both code and data
Expansion Memory (Optional in 176-pin package)
Up to 1 Mbyte of additional code and data
Supports BIOS (flash) memory sharing with PC host
Supports external memory power-down mode
Field upgradable with flash or SRAM devices
Supports host-controlled code download and up-
date
Bus Interface Unit (BIU)
Three address zones for static devices (SRAM,
ROM, flash, I/O)
Configurable wait states and fast-read, single-
cycle bus cycles
8- or 16-bit wide bus
LPC System Interface
Synchronous cycles, up to 33 MHz bus clock
Serial IRQ
I/O and Memory read and write cycles
Bootable memory support
Bus Master read and write cycles
Reset input
Base Address (BADDR) strap to determine the base
address of the Index-Data register pair
LPCPD and CLKRUN support
FWH Transaction support
Security Function Support
Random Number Generator (RNG)
Full Random using temperature, voltage and system
noise.
Memory access protection
Embedded Controller System Features
Host Bus Interface (HBI)
Three host interface channels, typically used for the
KBC, ACPI Private or Shared EC channels
8042 KBC standard Interface (legacy 6016, 6416)
Intel 80C51SL compatible
IRQ1 and IRQ12 support
Fast Gate A20 and Fast Host Reset via firmware
PM interface port (legacy 6216, 6616)
ACPI Embedded Controller with either Shared or
Private interface
IRQ, SMI or SCI generation
Function PC87591E
128-Pin PC87591E
176-Pin PC87591S
128-Pin PC87591S
176-Pin PC87591L
176-Pin
Flash Size 64K 64K 128K 128K
ROMSize ––––4K
RAMSize 2K2K4K4K2K
General-Purpose Input/Output Ports (GPIO) 62 93 62 93 93
Shared BIOS NO YES NO YES YES
RNG NO NO YES YES NO
Memory Protection NO NO YES YES YES
Revision 1.07 3 www.national.com
PC87591E/S/L
Features (Continued)
Interrupt Control Unit (ICU)
31 maskable vectored interrupts (of which 26 are ex-
ternal)
General-purpose external interrupt inputs through
MIWU
Enable and pending indication for each interrupt
Non-maskable interrupt input
Multi-Input Wake-Up (MIWU)
Supports up to 32 wake-up or interrupt inputs
Generates wake-up event to PMC (Power Manage-
ment Controller)
Generates interrupts to ICU
Provides user-selectable trigger conditions
General-Purpose I/O (GPIO)
84/117 port pins in 128-pin/176-pin package, re-
spectively.
I/O pins individually configured as input or output
Configurable internal pull-up resistors
Special ports for internal keyboard matrix scanning
16 open-collector outputs
Eight Schmitt inputs with internal pull-ups
Input for system On/Off switch
27 external wake-up events
Low-cost external GPIO expansion through the
BIU I/O Expansion protocol
PS/2 Interface
Supports four external ports: Keyboard, mouse and
two additional pointing devices
Supports byte-level handling via hardware accelera-
tor
Two ACCESS.bus (ACB) Interface modules. Each is:
Intel SMBus® and Philips I2C® compatible
ACCESS.bus master and slave
Up to three simultaneous slave addresses detected
Supports polling and interrupt controlled operation
Generates a wake-up signal on detection of a Start
Condition while in Idle mode
Optional internal pull-up on SDA and SCL pins
Two 16-bit Multi Function Timer (MFT16) modules.
Each module:
Contains two 16-bit timers
Supports Pulse Width Modulation (PWM), Capture
and Counter
Universal Synchronous/ Asynchronous Receiver-trans-
mitter (USART)
A full-duplex USART channel
Programmable baud rate
Data transfer via interrupt or polling
Synchronous mode with either internal or external
clock
7-, 8- or 9-bit protocols.
Pulse Width Modulation (PWM) Module
Eight outputs
8-bit duty cycle resolution
Common input clock prescaler
Timer and WATCHDOG (TWM)
16-bit periodic interrupt timer with 30 µs resolution
and 5-bit prescaler for system tick and periodic
wake-up tasks
8-bit WATCHDOG timer
Analog to Digital Converter (ADC)
Fourteen channels, with 10-bit resolution
Sigma-delta technology for high noise rejection
Three voltage measurements and one temperature
measurement every 100 ms
Internal voltage reference
Hardware Monitoring
Controlled by embedded controller
System Voltage Measurement
Up to eight external measurement points
Four internal measurement points
Smart power failure detection
Diode-Based Temperature Measurement
Software-controlled fault detection
Hardware-monitored over-temperature detection
Production time calibration using flash parameters
Digital to Analog Converter (DAC)
Four channels, 8-bit resolution
1µs conversion time for 50 pF load
Full output range from AGND to AVCC
Analog Comparators Monitor (ACM)
Eight comparator inputs on KBD scan inputs
6-bit input measurement resolution
Scan and Threshold modes
Supports low-current system wake-up
Development Support Features
Interface to debugger via JTAG pins
ISE/ADB mode
On-board Debug mode
Flash programing via JTAG
CR16B Access to Host Controlled Functions
Enabled when host inactive
Host Controlled Functions Features
Supports Microsoft®Advanced Power Management
(APM) Specifications Revision 1.2, February 1996
Generates the System Management Interrupt (SMI)
PC1 and ACPI Compliant
PnP Configuration Register structure
Flexible resource allocation for all logical devices
Relocatable base address
www.national.com 4 Revision1.07
Features (Continued)
PC87591E/S/L
15 IRQ routing options
Legacy free support
Real-Time Clock (RTC)
DS1287 and MC146818 compatible
242-byte battery backed-up CMOS RAM
Calendar including century and automatic leap-year
adjustment (Y2K compliant)
Optional adjustment for daylight saving time
BCD or binary format for timekeeping
Three individually maskable interrupt event flags:
periodic rates from 122 µs to 500 ms; time-of-day
alarm, once-per-second to once-per-day
Double-buffer time registers
Alarm wake-up
Mobile System Wake-Up Control (MSWC)
Wake-up on detection of RI1, RI2, RING activity
External modem ring on serial port
Ring pulse or pulse train on RING input signal
Software-controlled off events
Optional routing of power-up request on IRQ and/or
SMI lines
Clocking, Supply and Package Information
Strap Input Controlled Operating Modes
Turn on shared BIOS
TRI-STATE
Development
On-board development
Programing environment
Clocks
Single 32.768 KHz crystal oscillator
LPC clock, up to 33 MHz
On-chip high frequency clock generator
CPU clock 4-20 MHz
Software-controlled frequency generation
Multiplier source 32 KHz input
32 KHz clock out
CR16B clock out
Power Supply
3.3V supply operation
5V tolerance and back-drive protection on all pins
(except LPC bus pins and keyboard scan inputs)
Separate supply for Host I/F (VDD) and Embedded
Controller functions (VCC)
Backup battery input for RTC, and wake-up configu-
ration.
Reduced power consumption capability
Four power modes, switched by software or hard-
ware
Active mode current (TBD mA)
Active mode executing WAIT
Idle (15 µA)
Power off for RTC only (0.9 µA typical) from
backup battery
Automatic wake-up on system events
Package Options
128-pin LQFP package
176-pin LQFP package for more GPIO pins, Expan-
sion Memory use and development systems
Revision 1.07 5 www.national.com
PC87591E/S/L
Revision Record
Revision Date Status Comments
April 11, 00 0.13 External version of Architectural Specification
December 25, 00 1.0 Preliminary
May 1, 01 1.02 Preliminary
May 8, 01 1.03 Preliminary
July 19, 01 1.04 Preliminary
October 28, 01 1.05 Preliminary
July 2002 1.06 Preliminary
April 2004 1.07 Preliminary: All references to CSP package are removed in Rev 1.07.
www.national.com 6 Revision1.07
PC87591E/S/L
Table of Contents
Embedded Controller System Features .................................................................2
Host Controlled Functions Features ......................................................................3
Clocking, Supply and Package Information ...........................................................4
Revision Record ....................................................................................................5
1.0 Introduction
1.1 DOCUMENT ORGANIZATION ..................................................................................................23
1.2 GENERAL DESCRIPTION ........................................................................................................23
1.2.1 System Connections ....................................................................................................23
1.2.2 Power Management ....................................................................................................23
1.2.3 Operating Environments ..............................................................................................25
1.3 INTERNAL ARCHITECTURE ....................................................................................................25
1.3.1 Processing Unit ...........................................................................................................26
1.3.2 Bus Interface Unit and Memory Controller (BIU) .........................................................26
1.3.3 On-Chip Memory .........................................................................................................26
1.3.4 Peripherals ..................................................................................................................27
1.3.5 Host-Controller Interface Modules ...............................................................................28
1.3.6 Host-Controlled SuperI/O Modules and Host Interface ...............................................29
1.4 OPERATING ENVIRONMENTS ................................................................................................29
1.4.1 IRE Environment .........................................................................................................29
1.4.2 OBD Environment ........................................................................................................30
1.4.3 DEV Environment ........................................................................................................30
1.4.4 PROG Environment .....................................................................................................30
1.5 MEMORY MAP ..........................................................................................................................30
1.5.1 Core Address Domain Memory Map ...........................................................................33
Register Abbreviations and Access .....................................................................34
Accessing Base Memory .....................................................................................35
Accessing Expansion Memory .............................................................................36
Accessing I/O Expansion Space ..........................................................................37
1.5.2 Host Address Domain Memory Map ............................................................................38
1.5.3 Core Access to Host Controlled Peripherals ...............................................................38
2.0 Signal/Pin Description and Configuration
2.1 CONNECTION DIAGRAMS ......................................................................................................39
2.2 BUFFER TYPES AND SIGNAL/PIN DIRECTORY ....................................................................41
2.2.1 ACCESS.bus (ACB1 and ACB2) Interface ..................................................................42
2.2.2 Analog Interface ..........................................................................................................42
2.2.3 Clocks ..........................................................................................................................42
2.2.4 Core Bus Interface Unit (BIU) ......................................................................................43
2.2.5 Development System Support .....................................................................................44
2.2.6 General-Purpose I/O (GPIO) and Internal Keyboard Scan .........................................45
2.2.7 Host Interface ..............................................................................................................48
2.2.8 Interrupt and Wake-Up Inputs (ICU and MIWU) ..........................................................49
2.2.9 Power and Ground ......................................................................................................49
2.2.10 PS/2 Interface ..............................................................................................................50
2.2.11 Strap Configuration ......................................................................................................50
Table of Contents (Continued)
Revision 1.07 7 www.national.com
PC87591E/S/L
2.2.12 Mobile System Wake-Up Control (MSWC) ..................................................................51
2.2.13 Timers and PWM .........................................................................................................51
2.2.14 Universal Synchronous/Asynchronous Receiver/Transmitter (USART) ......................51
2.2.15 Internal Pull-Up and Pull-Down Resistors ...................................................................52
2.3 STRAP PINS .............................................................................................................................53
Setting the Environment ......................................................................................53
Other Strap Pin Settings ......................................................................................53
System Load on Strap Pins .................................................................................53
Strap Pin Status Register (STRPST) ...................................................................54
2.4 ALTERNATE FUNCTIONS ........................................................................................................54
2.4.1 GPIO with Alternate Functions ....................................................................................54
2.4.2 System Configuration Registers ..................................................................................58
Register Map .......................................................................................................58
Module Configuration Register (MCFG) ..............................................................58
External Interrupts Configuration Register (EICFG) ............................................59
2.4.3 GPIO with Echo Configuration .....................................................................................59
Input to Output Echo Enable Register 1 and 2 (IOEE1 and IOEE2) ....................60
3.0 Power, Reset and Clocks
3.1 POWER .....................................................................................................................................62
3.1.1 Power Planes ..............................................................................................................62
3.1.2 Power States ...............................................................................................................62
3.1.3 Power Connection and Layout Guidelines ..................................................................63
3.2 RESET SOURCES AND TYPES ...............................................................................................65
3.2.1 VPP Power-Up Reset ...................................................................................................66
3.2.2 VCC Power-Up Reset ...................................................................................................66
3.2.3 WATCHDOG Reset and Debugger Interface Reset ....................................................66
3.2.4 Warm Reset .................................................................................................................66
3.2.5 Host Domain Reset .....................................................................................................67
Using RESET2 Input ............................................................................................67
Host Domain Reset Actions .................................................................................67
3.3 CLOCK DOMAINS .....................................................................................................................68
LPC Clock ............................................................................................................68
RTC (32 KHz) Clock ............................................................................................68
4.0 Embedded Controller Modules
4.1 BUS INTERFACE UNIT (BIU) ...................................................................................................69
4.1.1 Features ......................................................................................................................69
4.1.2 Functional Description .................................................................................................69
Interface ...............................................................................................................69
Static Memory and I/O Support ...........................................................................69
Byte Access .........................................................................................................69
Clock and Bus Cycles ..........................................................................................70
4.1.3 Clock Cycles ................................................................................................................71
Optional Clock Cycles ..........................................................................................71
Other Clock Cycles ..............................................................................................71
Table of Contents (Continued)
www.national.com 8 Revision1.07
PC87591E/S/L
Control Signals ....................................................................................................72
4.1.4 Early Write Bus Cycle ..................................................................................................72
4.1.5 Late Write Bus Cycle ...................................................................................................74
4.1.6 Normal Read Bus Cycle ..............................................................................................76
4.1.7 Fast Read Bus Cycle ...................................................................................................79
4.1.8 I/O Expansion Bus Cycles ...........................................................................................80
4.1.9 Development Support ..................................................................................................81
Bus Status Signals ...............................................................................................81
Core Bus Monitoring ............................................................................................82
4.1.10 BIU Registers ..............................................................................................................83
BIU Configuration Register (BCFG) .....................................................................83
I/O Zone Configuration Register (IOCFG) ...........................................................84
Static Zone Configuration Register (SZCFGn) ....................................................85
4.1.11 Usage Hints .................................................................................................................86
4.2 DMA CONTROLLER (DMAC) ...................................................................................................87
4.2.1 Features ......................................................................................................................87
4.2.2 Functional Description .................................................................................................87
4.2.3 Channel Assignment in PC87591x ..............................................................................87
4.2.4 Transfer Types ............................................................................................................88
Direct (Fly-By) Transfers ......................................................................................88
Indirect (Memory-to-Memory) Transfers ..............................................................89
4.2.5 Bus Policy ....................................................................................................................90
Intermittent Operation Mode ................................................................................90
Continuous Operation Mode ................................................................................90
4.2.6 Operation Modes .........................................................................................................91
Single Transfer Operation ....................................................................................91
Double Buffer Operation ......................................................................................91
Auto-Initialize Operation ......................................................................................92
4.2.7 Software DMA Request ...............................................................................................92
4.2.8 DMAC Registers ..........................................................................................................92
DMAC Register Map ............................................................................................92
Device A Address Counter Register (ADCAn) .....................................................93
Device A Address Register (ADRAn) ..................................................................93
Device B Address Counter Register (ADCBn) .....................................................93
Device B Address Register (ADRBn) ..................................................................93
Block Length Counter Register (BLTCn) .............................................................94
Block Length Register (BLTRn) ...........................................................................94
DMA Control Register (DMACNTLn) ...................................................................94
DMA Status Register (DMASTATn) .....................................................................96
4.2.9 Usage Hints .................................................................................................................97
4.3 INTERRUPT CONTROL UNIT (ICU) .........................................................................................98
4.3.1 Features ......................................................................................................................98
4.3.2 Non-Maskable Interrupt (NMI) .....................................................................................98
External NMI Inputs .............................................................................................98
Non-Maskable Interrupt Processing ....................................................................98
PFAIL Input ..........................................................................................................98
4.3.3 Maskable Interrupts .....................................................................................................98
Maskable Interrupt Vectors ..................................................................................99
Table of Contents (Continued)
Revision 1.07 9 www.national.com
PC87591E/S/L
Pending Interrupts ...............................................................................................99
Interrupt Priorities ................................................................................................99
Power-Down Modes ............................................................................................99
External Interrupt Inputs ......................................................................................99
Interrupt Assignment ............................................................................................99
4.3.4 ICU Registers ............................................................................................................101
ICU Register Map ..............................................................................................101
Interrupt Vector Register (IVCT) ........................................................................101
NMI Status Register (NMISTAT) .......................................................................101
Power Fail Interrupt Control and Status Register (PFAIL) .................................102
Interrupt Status Register 0 (ISTAT0) .................................................................102
Interrupt Status Register 1 (ISTAT1) .................................................................103
Interrupt Enable and Mask Register 0 (IENAM0) ..............................................103
Interrupt Enable and Mask Register 1 (IENAM1) ..............................................103
Edge Interrupt Clear Register 0 (IECLR0) .........................................................104
Edge Interrupt Clear Register 1 (IECLR1) .........................................................104
4.3.5 Usage Hints ...............................................................................................................104
Initializing ...........................................................................................................104
Clearing .............................................................................................................104
Nesting ...............................................................................................................104
4.4 MULTI-INPUT WAKE-UP (MIWU) ...........................................................................................105
4.4.1 Features ....................................................................................................................105
4.4.2 Operation ...................................................................................................................105
4.4.3 MIWU Registers ........................................................................................................109
MIWU Register Map ..........................................................................................109
Edge Detection Register (WKEDG1) .................................................................109
Edge Detection Register (WKEDG2) .................................................................110
Edge Detection Register (WKEDG3) .................................................................110
Edge Detection Register (WKEDG4) .................................................................110
Pending Register (WKPND1) ............................................................................110
Pending Register (WKPND2) ............................................................................110
Pending Register (WKPND3) ............................................................................110
Pending Register (WKPND4) ............................................................................111
Enable Register (WKEN1) .................................................................................111
Enable Register (WKEN2) .................................................................................111
Enable Register (WKEN3) .................................................................................111
Enable Register (WKEN4) .................................................................................111
Pending Clear Register (WKPCL1) ...................................................................111
Pending Clear Register (WKPCL2) ...................................................................112
Pending Clear Register (WKPCL3) ...................................................................112
Pending Clear Register (WKPCL4) ...................................................................112
4.4.4 Usage Hints ...............................................................................................................112
4.5 GENERAL-PURPOSE I/O (GPIO) PORTS .............................................................................113
GPIO Port Functionality .....................................................................................113
4.5.1 Features ....................................................................................................................114
4.5.2 GPIO Port Px .............................................................................................................114
Bidirectional Port with Alternate Function ..........................................................114
4.5.3 GPI Port Py ................................................................................................................116
Input Only Port with Alternate Function .............................................................116
4.5.4 GPO Port Pz ..............................................................................................................117
Output Only Port with Alternate Function ..........................................................117
Table of Contents (Continued)
www.national.com 10 Revision1.07
PC87591E/S/L
4.5.5 GPIO Port Pw ............................................................................................................118
GPIO Port Signals Shared with Development System Signals .........................118
4.5.6 GPIO Port Registers ..................................................................................................119
GPIO Register Map ...........................................................................................119
Port Alternate Function Registers (PxALT, PyALT and PzALT) ........................119
Port Direction Registers (PxDIR and PwDIR) ....................................................120
Port Data Output Register (PxDOUT, PzDOUT and PwDOUT) ........................120
Port Data Input Registers (PxDIN, PyDIN and PwDIN) .....................................120
Port Weak Pull-Up Registers (PxWPU, PyWPU) ..............................................121
4.6 PS/2 INTERFACE ....................................................................................................................122
4.6.1 Features ....................................................................................................................122
4.6.2 General Description ...................................................................................................122
4.6.3 Operating With the Shift Mechanism Disabled ..........................................................124
4.6.4 Operating With the Shift Mechanism Enabled ...........................................................125
Receive Mode ....................................................................................................126
Transmit Mode ...................................................................................................127
4.6.5 PS/2 Interface Registers ............................................................................................128
PS/2 Register Map .............................................................................................129
PS/2 Data Register (PSDAT) .............................................................................129
PS/2 Status Register (PSTAT) ..........................................................................129
PS/2 Control Register (PSCON) ........................................................................130
PS/2 Output Signal Register (PSOSIG) .............................................................131
PS/2 Input Signal Register (PSISIG) .................................................................132
PS/2 Interrupt Enable Register (PSIEN) ............................................................133
4.7 MULTI-FUNCTION 16-BIT TIMER (MFT16) ...........................................................................134
4.7.1 Features ....................................................................................................................134
4.7.2 Clock Source Unit ......................................................................................................135
Pre-Scaler ..........................................................................................................135
External Event Clock .........................................................................................135
Pulse Accumulate Mode ....................................................................................135
Slow-Speed Clock .............................................................................................135
Counter Clock Source Select .............................................................................136
4.7.3 Timer/Counter and Action Unit ..................................................................................136
Operation Modes ...............................................................................................136
Mode 1, PWM and Counter ...............................................................................136
Mode 2, Dual Input Capture ...............................................................................137
Mode 3, Dual Independent Timer ......................................................................138
Mode 4, Input Capture and Timer ......................................................................139
4.7.4 Timer Interrupts .........................................................................................................140
4.7.5 Timer I/O Functions ...................................................................................................141
4.7.6 Operation in Development System ............................................................................141
4.7.7 MFT16 Registers .......................................................................................................142
MFT16 Register Map .........................................................................................142
Timer/Counter Register 1 (TnCNT1) .................................................................142
Reload/Capture Register A (TnCRA) .................................................................142
Reload/Capture Register B (TnCRB) .................................................................142
Timer/Counter Register 2 (TnCNT2) .................................................................143
Clock Pre-Scaler Register (TnPRSC) ................................................................143
Clock Unit Control Register (TnCKC) ................................................................143
Timer Mode Control Register (TnCTRL) ............................................................144
Table of Contents (Continued)
Revision 1.07 11 www.national.com
PC87591E/S/L
Timer Interrupt Control Register (TnICTL) .........................................................145
Timer Interrupt Clear Register (TnICLR) ...........................................................146
4.8 PULSE WIDTH MODULATOR (PWM) ....................................................................................147
4.8.1 Features ....................................................................................................................147
4.8.2 Functional Description ...............................................................................................147
4.8.3 Cycle Time and Duty Cycle Calculation ....................................................................148
4.8.4 Power Modes .............................................................................................................148
4.8.5 PWM Registers ..........................................................................................................148
PWM Register Map ............................................................................................148
Clock Pre-Scaler Register (PRSC) ....................................................................148
Cycle Time Register (CTR) ................................................................................149
Duty Cycle Registers 0 to 7 (DCRi) ...................................................................149
PWM Polarity Register (PWMPOL) ...................................................................150
PWM Control Register (PWMCNT) ...................................................................150
4.9 UNIVERSAL SYNCHRONOUS/ASYNCHRONOUS RECEIVER-TRANSMITTER (USART) ..151
4.9.1 Features ....................................................................................................................151
4.9.2 Functional Overview ..................................................................................................151
4.9.3 Operation ...................................................................................................................153
4.9.4 USART Registers ......................................................................................................158
USART Register Map ........................................................................................158
Receive Data Buffer Register (URBUF) ............................................................158
Transmit Data Buffer Register (UTBUF) ............................................................158
Baud Rate Pre-Scaler Register (UPSR) ............................................................158
Baud Rate Divisor Register (UBAUD) ...............................................................158
Frame Select Register (UFRS) ..........................................................................159
Mode Select Register (UMDSL) ........................................................................160
Status Register (USTAT) ...................................................................................161
Interrupt Control Register (UICTRL) ..................................................................162
4.9.5 Usage Hints ...............................................................................................................162
4.10 TIMER AND WATCHDOG (TWD) ...........................................................................................164
4.10.1 Features ....................................................................................................................164
4.10.2 Functional Description ...............................................................................................164
4.10.3 TWD Registers ..........................................................................................................166
TWD Register Map ............................................................................................166
Timer and WATCHDOG Configuration Register (TWCFG) ...............................166
Timer and WATCHDOG Clock Pre-Scaler Register (TWCP) ............................167
TWD Timer 0 Register (TWDT0) .......................................................................167
TWDT0 Control and Status Register (T0CSR) ..................................................168
WATCHDOG Count Register (WDCNT) ............................................................168
WATCHDOG Service Data Match Register (WDSDM) .....................................168
4.10.4 Usage Hints ...............................................................................................................169
4.11 ANALOG TO DIGITAL CONVERTER (ADC) ..........................................................................170
4.11.1 Features ....................................................................................................................170
4.11.2 Functional Description ...............................................................................................170
4.11.3 Voltage Measurement ...............................................................................................173
4.11.4 Temperature Measurement .......................................................................................173
4.11.5 ADC Operation ..........................................................................................................174
Reset .................................................................................................................174
ADC Clock .........................................................................................................174
Table of Contents (Continued)
www.national.com 12 Revision1.07
PC87591E/S/L
Initializing the ADC ............................................................................................174
Enabling and Disabling the ADC .......................................................................174
Interrupt Structure ..............................................................................................175
ADC Operating Principles ..................................................................................175
Reading Measurement Results .........................................................................176
Failure Detection ................................................................................................177
4.11.6 ADC Registers ...........................................................................................................177
ADC Register Map .............................................................................................177
ADC Status Register (ADCSTS) ........................................................................178
ADC Configuration Register (ADCCNF) ............................................................179
ADC Clock Control Register (ACLKCTL) ...........................................................179
ADC Delay Control Register (ADLYCTL) ..........................................................180
Local Diode Overtemperature Limit Register (TLOCOTL) .................................181
ADC Parameters Index Register (ADCPINX) ....................................................181
ADC Parameters Data Register (ADCPD) .........................................................181
Temperature Channel Control Register (TCHANCTL) ......................................182
Temperature Channel Data Buffer (TCHANDAT) ..............................................182
Voltage Channel 1 Control Register (VCHN1CTL) ............................................183
Voltage Channel 1 Data Buffer (VCHN1DAT) ...................................................184
Voltage Channel 2 Control Register (VCHN2CTL) ............................................184
Voltage Channel 2 Data Buffer (VCHN2DAT) ...................................................184
Voltage Channel 3 Control Register (VCHN3CTL) ............................................185
Voltage Channel 3 Data Buffer (VCHN3DAT) ...................................................185
4.11.7 Usage Hints ...............................................................................................................185
Power Supply and Layout Guidelines ................................................................185
Power Consumption ..........................................................................................185
Back-Drive Protection ........................................................................................185
Measuring Out of Range Voltages .....................................................................185
Filtering the Noise on Voltage Input Signals ......................................................186
Calculating the Voltage Channel Delay .............................................................186
Thermistor-Based Temperature Measurement ..................................................186
Remote Diode Selection ....................................................................................187
Filtering the Noise on Temperature Input Signals .............................................187
Calculating the Temperature Channel Delay .....................................................188
PC Board Layout ...............................................................................................188
Twisted Pair and Shielded Cables .....................................................................189
4.12 DIGITAL TO ANALOG CONVERTER (DAC) ..........................................................................190
4.12.1 Features ....................................................................................................................190
4.12.2 Functional Description ...............................................................................................190
4.12.3 D/A Conversion .........................................................................................................190
Output Signal .....................................................................................................190
Reference Voltage .............................................................................................191
Conversion Time ................................................................................................191
4.12.4 Operation ...................................................................................................................192
Initializing the DAC ............................................................................................192
Enabling and Disabling the DAC .......................................................................192
4.12.5 DAC Registers ...........................................................................................................193
DAC Register Map .............................................................................................193
DAC Control Register (DACCTRL) ....................................................................193
DAC Data Channel 0-3 Registers (DACDAT0-3) ..............................................194
4.12.6 Usage Hints ...............................................................................................................194
Power Consumption ..........................................................................................194
Table of Contents (Continued)
Revision 1.07 13 www.national.com
PC87591E/S/L
DAC Output Protection ......................................................................................194
Output Voltage Accuracy ...................................................................................194
Output Settling Time ..........................................................................................195
Filtering Noise on Output Signals ......................................................................195
4.13 ACCESS.BUS (ACB) INTERFACE .........................................................................................196
4.13.1 Features ....................................................................................................................196
4.13.2 Functional Description ...............................................................................................196
“Acknowledge After Every Byte” Rule ................................................................198
4.13.3 Master Mode ..............................................................................................................199
4.13.4 Slave Mode ................................................................................................................201
4.13.5 Power-Down ..............................................................................................................201
4.13.6 SDA and SCL Pin Configuration ................................................................................201
4.13.7 ACB Clock Frequency Configuration .........................................................................202
4.13.8 ACB Registers ...........................................................................................................202
ACB Register Map .............................................................................................202
ACB Serial Data Register (ACBnSDA) ..............................................................202
ACB Status Register (ACBnST) ........................................................................203
ACB Control Status Register (ACBnCST) .........................................................204
ACB Control Register 1 (ACBnCTL1) ................................................................205
ACB Own Address Register (ACBnADDR and ACBnADDR2) ..........................206
ACB Control Register 2 (ACBnCTL2) ................................................................206
ACB Control Register 3 (ACBnCTL3) ................................................................207
4.13.9 Usage Hints ...............................................................................................................207
4.14 ANALOG COMPARATORS MONITOR (ACM) .......................................................................208
4.14.1 Features ....................................................................................................................208
4.14.2 Functional Description ...............................................................................................208
4.14.3 Voltage Level .............................................................................................................209
4.14.4 ACM Operation ..........................................................................................................210
Reset .................................................................................................................210
Sampling Delay ..................................................................................................210
Initializing the ACM ............................................................................................210
Interrupt Structure ..............................................................................................211
ACM Operating Sequences ...............................................................................211
4.14.5 ACM Registers ..........................................................................................................212
ACM Register Map ............................................................................................212
ACM Control and Status Register (ACMCTS) ...................................................213
ACM Configuration Register (ACMCNF) ...........................................................214
ACM Timing Control Register (ACMTIM) ..........................................................215
Comparison Threshold Data Register (THRDAT) .............................................216
Comparison Result Register (CMPRES) ...........................................................216
Voltage Level Data Buffer - Input 0 through 7 (VOLDAT0-7) ............................217
4.14.6 Usage Hints ...............................................................................................................217
Voltage Level Burst ............................................................................................217
4.15 ON-CHIP RAM .........................................................................................................................218
4.16 ON-CHIP FLASH .....................................................................................................................218
4.16.1 Features ....................................................................................................................218
4.16.2 Functional Description ...............................................................................................219
4.16.3 Flash Interface States and Timing Control ................................................................222
Table of Contents (Continued)
www.national.com 14 Revision1.07
PC87591E/S/L
4.16.4 Flash Access and Control ..........................................................................................224
4.16.5 Parallel Flash Interface ..............................................................................................226
4.16.6 Flash Protection .........................................................................................................226
4.16.7 Flash Interface Registers ...........................................................................................228
Information Block Access Index Register (IBAI) ................................................228
Information Block Data Register (IBD) ...............................................................229
Flash Core Write Protect Register 0 (FCWP0) ..................................................229
Flash Memory Control Register (FLCR) ............................................................230
Flash Memory Status Register (FLSR) ..............................................................231
Flash Memory Pre-Scaler Register (FLPSLR) ...................................................231
Flash Memory Start Time Register (FLSTART) .................................................232
Flash Memory Transition Time Register (FLTRAN) ..........................................232
Flash Memory Program Time Register (FLPROG) ............................................232
Flash Memory Page Erase Time Register (FLPERASE) ...................................233
Flash Memory Section Erase Time Register (FLSERASE) ...............................233
Flash Memory End Time Register (FLEND) ......................................................233
Flash Memory Section Erase End Time Register (FLSEND) ............................234
Flash Memory Recovery Time Register (FLRCV) .............................................234
4.17 POWER MANAGEMENT CONTROLLER (PMC) ...................................................................235
4.17.1 Features ....................................................................................................................235
4.17.2 The Core Domain Power Modes ...............................................................................235
4.17.3 Switching Between Power Modes .............................................................................236
Decreasing Power Consumption .......................................................................236
Increasing Activity ..............................................................................................236
Power Mode Switch Protection ..........................................................................237
4.17.4 The Power Management Controller Status Register (PMCSR) .................................237
4.17.5 Usage Hints ...............................................................................................................238
4.18 HIGH-FREQUENCY CLOCK GENERATOR (HFCG) .............................................................239
4.18.1 Features ....................................................................................................................239
4.18.2 Functional Description ...............................................................................................239
4.18.3 HFCG States .............................................................................................................240
PMC Enabled SuperI/O Disabled State .............................................................240
SuperI/O Enabled State .....................................................................................242
4.18.4 The Programmable Pre-Scaler: Core Domain Clock Generation ..............................242
4.18.5 State Transitions ........................................................................................................242
4.18.6 48 MHz Clock Monitor ...............................................................................................243
4.18.7 HFCG Registers .......................................................................................................243
HFCG Register Map ..........................................................................................243
HFCG Control Register 1 (HFCGCTRL1) ..........................................................244
HFCGM Low Value Register (HFCGML) ...........................................................245
HFCGM High Value Register (HFCGMH) .........................................................245
HFCGN Value Register (HFCGN) .....................................................................245
HFCGI Low Value Register (HFCGIL) ...............................................................246
HFCGI High Value Register (HFCGIH) .............................................................246
HFCG Pre-Scaler Register (HFCGP) ................................................................246
HFCG Control Register 2 (HFCGCTRL2) ..........................................................247
4.19 THE DEBUGGER INTERFACE ...............................................................................................248
4.19.1 Features ....................................................................................................................248
4.19.2 Structure ....................................................................................................................248
Table of Contents (Continued)
Revision 1.07 15 www.national.com
PC87591E/S/L
4.19.3 Debugger Interface Functional Description ...............................................................249
Rx Data Link ......................................................................................................249
TX Data Link ......................................................................................................250
Debugger Reset Circuit .....................................................................................250
ISE Interrupt Control ..........................................................................................250
Clock Synchronization .......................................................................................251
4.19.4 Flash Interface Functional Description ......................................................................251
4.19.5 Test Access Port (TAP) .............................................................................................253
TAP Signals .......................................................................................................254
TAP Controller ...................................................................................................254
4.19.6 TAP Instruction Register ............................................................................................256
Design and Construction ...................................................................................256
Instruction Register Operation ...........................................................................257
Instructions ........................................................................................................258
Flash Support Instructions .................................................................................258
Debugger Interface Instructions .........................................................................259
4.19.7 TAP Data Registers, Debugger Interface ..................................................................260
Bit Arrangement and Mapping ...........................................................................260
Functionality in Various TAP Controller States ..................................................260
Debug Bypass Register (BYPASS) ...................................................................261
Debug Data Register (DBGDATA) ....................................................................261
Debug Abort Mask Register (DBGMASKS) .......................................................261
4.19.8 TAP Data Registers, Flash Interface .........................................................................262
Flash Control and Status Register (FL_CT_ST) ................................................262
Flash Identification Register (FL_ID) .................................................................263
Flash Address Register (FL_ADDR) ..................................................................264
Flash Data Register (FL_DATA) ........................................................................265
Flash Erase Register (FL_ERASE) ...................................................................266
4.19.9 Core Registers, Debugger Interface ..........................................................................267
Core Register Map .............................................................................................267
Debug Receive Data Registers 0, 2, 4, 6, 8, 10, 12 and 14 (DBGRXD0-14) ....267
Debug Receive Status Register (DBGRXST) ....................................................268
Debug Transmit Data Registers 0, 2, 4, 6, 8, 10, 12 and 14 (DBGTXD0-14) ....268
Debug Transmit Lock Register (DBGTXLOC) ...................................................269
Debug Transmit Status Register (DBGTXST) ...................................................269
Debug TINT Assert Register (DBGTINT) ..........................................................270
Debug Abort Generate Register (DBGABORT) .................................................270
Debug ISE Source Registers A (DBGISESRCA) ..............................................271
4.19.10 Usage Hints ..............................................................................................................271
4.20 DEVELOPMENT SYSTEM SUPPORT ...................................................................................272
4.20.1 Features ....................................................................................................................272
4.20.2 The ISE Interrupt .......................................................................................................272
4.20.3 Break Line and Reset Output Interrupt ......................................................................272
4.20.4 TRIS Strap Input Pin ..................................................................................................272
4.20.5 Freezing Events .........................................................................................................273
4.20.6 Monitoring Activity During Development ....................................................................273
Bus Status Signals .............................................................................................273
Transaction Effect on the External Bus .............................................................274
Pipe Status Signals (PFS and PLI) ....................................................................274
4.20.7 On-Chip Hardware Breakpoint ..................................................................................274
Table of Contents (Continued)
www.national.com 16 Revision1.07
PC87591E/S/L
4.20.8 CR16B Development Support Registers ...................................................................275
Debug Configuration Register (DBGCFG) .........................................................275
Debug Freeze Enable Register (DBGFRZEN) ..................................................276
5.0 Host Controller Interface Modules
5.1 KEYBOARD AND MOUSE CONTROLLER INTERFACE .......................................................277
5.1.1 Features ....................................................................................................................277
5.1.2 General Description ...................................................................................................277
Host Addresses .................................................................................................277
Core Interrupts ...................................................................................................277
Host Interrupts ...................................................................................................277
Keyboard/Mouse Channel (6016, 6416) ............................................................278
Status Read .......................................................................................................279
5.1.3 Host Interface Registers ............................................................................................280
Host Interface Register Map .............................................................................280
Data Out Buffer Register (DBBOUT, Legacy 6016) ..........................................280
Status Register (STATUS, Legacy 6416) ..........................................................281
Data In Buffer Register (DBBIN, Legacy 6016) .................................................281
Command In Buffer Register (COMAND, Legacy 6416) ...................................281
5.1.4 Core Interface Registers ............................................................................................282
Core Interface Register Map ..............................................................................282
Host Interface Control Register (HICTRL) .........................................................282
Host Interface IRQ Control Register (HIIRQC) ..................................................283
Host Interface Keyboard/Mouse Status Register (HIKMST) ..............................284
Host Interface Keyboard Data Out Buffer Register (HIKDO) .............................284
Host Interface Mouse Data Out Buffer Register (HIMDO) .................................285
Host Interface Keyboard/Mouse Data In Buffer Register (HIKMDI) ...................285
5.2 POWER MANAGEMENT (PM) CHANNELS ...........................................................................285
5.2.1 Features ....................................................................................................................285
5.2.2 General Description ...................................................................................................286
Host Addresses .................................................................................................286
Core Interrupts ...................................................................................................287
Host Interrupt Generation Modes ......................................................................287
Status Read .......................................................................................................289
Host Data Read from Host Interface Power Management Channel ..................290
5.2.3 Core PM Registers ....................................................................................................290
Core PM Register Map ......................................................................................291
Host Interface PM n Status Register (HIPMnST) ..............................................291
Host Interface PM n Data Out Buffer (HIPMnDO) .............................................292
Host Interface PM n Data Out Buffer with SCI (HIPMnDOC) ............................292
Host Interface PM n Data Out Buffer with SMI (HIPMnDOM) ...........................292
Host Interface PM n Data In Buffer (HIPMnDI) ..................................................293
Host Interface PM n Data In Buffer with SCI (HIPMnDIC) .................................293
Host Interface PM n Control Register (HIPMnCTL) ...........................................294
Host Interface PM n Interrupt Control Register (HIPMnIC) ................................295
Host Interface PM n Interrupt Enable Register (HIPMnIE) ................................296
5.3 SHARED MEMORY AND SECURITY .....................................................................................297
5.3.1 Host Bus to Core Bus Access Translation .................................................................297
5.3.2 Memory Mapping and Host Address Translation ......................................................297
5.3.3 Indirect Memory Read and Write Transaction ...........................................................300
Table of Contents (Continued)
Revision 1.07 17 www.national.com
PC87591E/S/L
5.3.4 Locking Between Domains ........................................................................................300
5.3.5 Host Access Protection .............................................................................................301
Response to a Restricted Access ......................................................................302
5.3.6 Random Number Generator (PC87591S) .................................................................303
5.3.7 Signaling Interface .....................................................................................................303
5.3.8 Shared Memory Host Registers ................................................................................303
Shared Memory Indirect Memory Address Register 0 (SMIMA0) ......................304
Shared Memory Indirect Memory Address Register 1 (SMIMA1) ......................304
Shared Memory Indirect Memory Address Register 2 (SMIMA2) ......................304
Shared Memory Indirect Memory Address Register 3 (SMIMA3) ......................304
Shared Memory Indirect Memory Data Register (SMIMD) ................................305
Shared Memory Host Control Register (SMHC) ................................................305
Shared Memory Host Status Register (SMHST) ...............................................305
Shared Memory Host Access Protect Register 1 and 2 (SMHAP1-2) ...............306
Shared Memory Host Semaphore Register (SMHSEM) ....................................306
5.3.9 Shared Memory Core Registers ................................................................................307
Shared Memory Core Control and Status Register (SMCCST) .........................307
Shared Memory Core Top Address Register (SMCTA) .....................................308
Shared Memory Host Semaphore Register (SMHSEM) ....................................308
Shared Memory Core Override Read Protect Registers 0-2 (SMCORP0-2) .....309
Shared Memory Core Override Write Protect Registers 0-2 (SMCOWP0-2) ....310
Random Number Generator Control/Status Register, RNGCS (PC87591S) ....311
Random Number Generator Data Register, RNGD (PC87591S) ......................312
5.3.10 Usage Hints ...............................................................................................................312
5.4 CORE ACCESS TO HOST-CONTROLLED MODULES .........................................................313
5.4.1 Core Access to Host-Controlled Module Registers ...................................................314
Indirect Host I/O Address Register (IHIOA) .......................................................314
Indirect Host Data Register (IHD) ......................................................................314
Lock SuperI/O Host Access Register (LKSIOHA) .............................................315
SuperI/O Access Lock Violation Register (SIOLV) ............................................315
Core to SIB Modules Access Enable Register (CRSMAE) ................................316
SIB Control Register (SIBCTRL) .......................................................................317
5.5 MOBILE SYSTEM WAKE-UP CONTROL (MSWC) ................................................................318
5.5.1 Features ....................................................................................................................318
5.5.2 Wake-Up Event Detection and Status Bits ................................................................318
5.5.3 Wake-Up Output Events ............................................................................................320
5.5.4 Other MSWC Controlled Elements ............................................................................322
Host Configuration Address Selection ...............................................................322
Host Keyboard Fast Reset .................................................................................322
GA20 Pin Functionality ......................................................................................322
5.5.5 MSWC Host Registers ...............................................................................................323
MSWC Host Register Map .................................................................................323
Wake-Up Event Status Register 0 (WK_STS0) .................................................323
Wake-Up Events Enable Register (WK_EN0) ...................................................324
Wake-Up Configuration Register (WK_CFG) ....................................................325
Wake-Up Signals Value Register (WK_SIGV) ...................................................325
Wake-Up ACPI State Register (WK_STATE) ....................................................326
Wake-Up Event Routing to SMI Enable Register 0 (WK_SMIEN0) ...................327
Wake-Up Event Routing to IRQ Enable Register 0 (WK_IRQEN0) ...................328
5.5.6 MSWC Core Registers ..............................................................................................328
Table of Contents (Continued)
www.national.com 18 Revision1.07
PC87591E/S/L
MSWC Control Status Register 1 (MSWCTL1) .................................................329
MSWC Control Status Register 2 (MSWCTL2) .................................................330
MSWC Control Status Register 3 (MSWCTL3) .................................................330
Host Configuration Base Address Low (HCFGBAL) ..........................................331
Host Configuration Base Address High (HCFGBAH) ........................................331
MSWC Interrupt Enable Register 2 (MSIEN2) ...................................................331
MSWC Host Event Status Register 0 (MSHES0) ..............................................332
MSWC Host Event Interrupt Enable Register (MSHEIE0) .................................333
5.5.7 Usage Hints ...............................................................................................................334
PWUREQ Output Connection ............................................................................334
RESET2 Events .................................................................................................334
6.0 Host-Controlled Modules and Host Interface
6.1 DEVICE ARCHITECTURE AND CONFIGURATION ..............................................................335
6.1.1 Configuration Structure and Access ..........................................................................335
The Index-Data Register Pair ............................................................................335
Banked Logical Device Registers Structure ......................................................336
Standard Logical Device Configuration Register Definitions .............................337
6.1.2 Standard Configuration Registers .............................................................................340
SuperI/O Control and Configuration Registers ..................................................340
Logical Device Control and Configuration Registers .........................................340
Control ...............................................................................................................340
Standard Configuration ......................................................................................341
Special Configuration .........................................................................................341
6.1.3 Default Configuration Setup ......................................................................................341
6.1.4 Address Decoding .....................................................................................................341
6.1.5 Interrupt Serializer .....................................................................................................342
6.1.6 Protection ..................................................................................................................342
6.1.7 LPC Interface .............................................................................................................342
LPC Transactions Supported .............................................................................342
Core Interrupt .....................................................................................................343
CLKRUN Functionality .......................................................................................343
LPCPD Functionality ..........................................................................................343
6.1.8 SuperI/O Configuration Registers ..............................................................................343
SuperI/O ID Register (SID) ................................................................................344
SuperI/O Configuration 1 Register (SIOCF1) ....................................................344
SuperI/O Configuration 5 Register (SIOCF5) ....................................................345
SuperI/O Configuration 6 Register (SIOCF6) ....................................................345
SuperI/O Revision ID Register (SRID) ...............................................................346
SuperI/O Configuration 8 Register (SIOCF8) ....................................................346
SuperI/O Configuration 9 Register (SIOCF9) ....................................................347
SuperI/O Configuration D Register (SIOCFD) ...................................................347
6.1.9 Mobile System Wake-Up Control (MSWC) Configuration .........................................348
Logical Device 4 (MSWC) Configuration ...........................................................348
6.1.10 Keyboard and Mouse Controller (KBC) Configuration ...............................................348
Logical Devices 5 and 6 (Mouse and Keyboard) Configuration .........................348
6.1.11 Shared Memory Configuration ...................................................................................349
Logical Device 15 (0F16) (Shared Memory) Configuration ................................349
Memory Range Programing ...............................................................................350
Shared Memory Configuration Register ............................................................351
Table of Contents (Continued)
Revision 1.07 19 www.national.com
PC87591E/S/L
Shared Memory Base Address High Byte Register ...........................................351
Shared Memory Base Address Low Byte Register ............................................352
Shared Memory Size Configuration Register ....................................................352
6.1.12 Real Time Clock (RTC) Configuration .......................................................................353
Logical Device 16 (1016) RTC Configuration .....................................................353
RAM Lock Register (RLR) .................................................................................353
Date Of Month Alarm Register Offset (DOMAO) ...............................................354
Month Alarm Register Offset (MONAO) ............................................................354
Century Register Offset (CENO) .......................................................................354
6.1.13 Power Management Interface Channel 1 Configuration ............................................355
Logical Device 17 (1116) Power Management Channel 1 .................................355
6.1.14 Power Management Interface Channel 2 Configuration ............................................355
Logical Device 18 (1216) Power Management Channel 2 .................................355
6.2 REAL-TIME CLOCK (RTC) .....................................................................................................356
6.2.1 Bus Interface .............................................................................................................356
6.2.2 RTC Clock Generation ..............................................................................................356
6.2.3 Internal Oscillator .......................................................................................................356
6.2.4 External Oscillator .....................................................................................................357
Connections .......................................................................................................357
Signal Parameters .............................................................................................358
6.2.5 Timing Generation .....................................................................................................358
6.2.6 Timekeeping ..............................................................................................................358
6.2.7 Updating ....................................................................................................................359
6.2.8 Alarms .......................................................................................................................359
6.2.9 Power Supply ............................................................................................................360
6.2.10 System Bus Lockout ..................................................................................................361
6.2.11 Power-Up Detection ..................................................................................................361
6.2.12 Oscillator Activity .......................................................................................................362
6.2.13 Interrupt Handling ......................................................................................................362
6.2.14 Battery-Backed RAMs and Registers ........................................................................363
6.2.15 RTC Registers ...........................................................................................................363
Seconds Register (SEC) ....................................................................................364
Seconds Alarm Register (SECA) .......................................................................365
Minutes Register (MIN) ......................................................................................365
Minutes Alarm Register (MINA) .........................................................................365
Hours Register (HOR) .......................................................................................365
Hours Alarm Register (HORA) ...........................................................................366
Day Of Week Register (DOW) ...........................................................................366
Date Of Month Register (DOM) .........................................................................366
Month Register (MON) .......................................................................................366
Year Register (YER) ..........................................................................................367
RTC Control Register A (CRA) ..........................................................................367
RTC Control Register B (CRB) ..........................................................................368
RTC Control Register C (CRC) ..........................................................................369
RTC Control Register D (CRD) ..........................................................................370
Date of Month Alarm Register (DOMA) .............................................................370
Month Alarm Register (MONA) ..........................................................................370
Century Register (CEN) .....................................................................................371
6.2.16 BCD and Binary Formats ...........................................................................................371
Table of Contents (Continued)
www.national.com 20 Revision1.07
PC87591E/S/L
6.2.17 Usage Hints ...............................................................................................................371
6.2.18 RTC General-Purpose RAM Map ..............................................................................371
7.0 Device Specifications
7.1 GENERAL DC ELECTRICAL CHARACTERISTICS ...............................................................372
7.1.1 Recommended Operating Conditions .......................................................................372
7.1.2 Absolute Maximum Ratings .......................................................................................372
7.1.3 Capacitance ..............................................................................................................373
7.1.4 Power Supply Current Consumption under Recommended Operating Conditions ...373
7.1.5 Voltage Thresholds ....................................................................................................373
7.2 DC CHARACTERISTICS OF PINS BY I/O BUFFER TYPES .................................................374
7.2.1 Input, CMOS Compatible with Schmitt Trigger ..........................................................374
7.2.2 Input, PCI 3.3V ..........................................................................................................374
7.2.3 Input, SMBus Compatible ..........................................................................................374
7.2.4 Input, TTL Compatible ...............................................................................................375
7.2.5 Input, TTL Compatible with Schmitt Trigger ..............................................................375
7.2.6 Output, TTL Compatible Push-Pull Buffer .................................................................375
7.2.7 Output, Open-Drain Buffer .........................................................................................376
7.2.8 Output, PCI 3.3V .......................................................................................................376
7.2.9 Exceptions .................................................................................................................376
7.2.10 Terminology ...............................................................................................................376
7.3 INTERNAL RESISTORS .........................................................................................................377
DC Test Conditions ............................................................................................377
7.3.1 Pull-Up Resistor .........................................................................................................377
7.3.2 Pull-Down Resistor ....................................................................................................377
7.4 ANALOG CHARACTERISTICS ...............................................................................................378
7.4.1 ADC Characteristics ..................................................................................................378
Voltage Measurement ........................................................................................378
Temperature Measurement ...............................................................................380
7.4.2 ACM Characteristics ..................................................................................................380
7.4.3 DAC Characteristics ..................................................................................................381
7.5 PACKAGE THERMAL INFORMATION ...................................................................................381
7.6 AC ELECTRICAL CHARACTERISTICS ..................................................................................382
7.6.1 AC Test Conditions ....................................................................................................382
Definitions ..........................................................................................................382
7.6.2 Reset Timing .............................................................................................................384
7.6.3 Clock Timing ..............................................................................................................385
General ..............................................................................................................386
7.6.4 BIU Timing .................................................................................................................388
7.6.5 GPIO Ports Timing ....................................................................................................393
7.6.6 PWM Timing ..............................................................................................................394
7.6.7 MSWC Timing ...........................................................................................................394
7.6.8 PS/2 Interface Timing ................................................................................................395
7.6.9 ACCESS.bus Timing .................................................................................................396
7.6.10 MFT16 Timing ...........................................................................................................399
Table of Contents (Continued)
Revision 1.07 21 www.national.com
PC87591E/S/L
7.6.11 ICU/Development Timing ..........................................................................................400
7.6.12 Asynchronous Edge Detected Signals Timing ..........................................................401
7.6.13 Debugger Interface Timing ........................................................................................402
7.6.14 USART Timing ...........................................................................................................404
7.6.15 LCLK and RESET1-2 ................................................................................................406
7.6.16 LPC and SERIRQ Signals .........................................................................................407
A. Software for Hardware Interface
A.1 CORE DOMAIN REGISTER LIST ...........................................................................................408
A.1.1 Module Configuration ................................................................................................408
A.1.2 Bus Interface Unit (BIU) .............................................................................................408
A.1.3 DMA Controller ..........................................................................................................408
A.1.4 General-Purpose I/O (GPIO) Ports ............................................................................409
A.1.5 PS/2 Ports .................................................................................................................411
A.1.6 Host Interface (KBC, PM1 and PM2Channels) .........................................................411
A.1.7 Multi-Function Timer (MTF16) 1 ................................................................................412
A.1.8 Multi-Function Timer (MFT16) 2 ................................................................................412
A.1.9 Timing and WATCHDOG (TWD) ...............................................................................413
A.1.10 Analog to Digital Converter (ADC) .............................................................................413
A.1.11 Digital to Analog Converter (DAC) .............................................................................413
A.1.12 ACCESS.bus Interface (ACB) 1 ................................................................................414
A.1.13 ACCESS.bus Interface (ACB) 2 ................................................................................414
A.1.14 Analog Comparators Monitor (ACM) .........................................................................414
A.1.15 Power Management (PM) ..........................................................................................415
A.1.16 High Frequency Clock Generator (HFCG) ................................................................415
A.1.17 Development System Support ...................................................................................415
A.1.18 Multi-Input Wake-Up (MIWU) ....................................................................................415
A.1.19 Interrupt Control Unit (ICU) ........................................................................................416
A.1.20 Debugger Interface ....................................................................................................416
A.1.21 Pulse Width Modulator (PWM) ..................................................................................417
A.1.22 Universal Synchronous/Asynchronous Receiver Transmitter (USART) ....................417
A.1.23 Flash Interface ...........................................................................................................418
A.1.24 Shared Memory Core ................................................................................................418
A.1.25 Core Access to SuperI/O ...........................................................................................419
A.1.26 Mobile System Wake-Up Control (MSWC) ................................................................419
A.2 HOST DOMAIN REGISTER LIST ...........................................................................................420
A.2.1 Configuration Registers .............................................................................................420
Common SuperI/O Configuration ......................................................................420
Shared Memory .................................................................................................420
RTC Configuration .............................................................................................420
A.2.2 Host Runtime Registers .............................................................................................420
Shared Memory Host .........................................................................................421
MSWC Host Registers .......................................................................................421
Host Interface (HI) .............................................................................................421
Power Management Channel 1 .........................................................................422
Table of Contents (Continued)
www.national.com 22 Revision1.07
PC87591E/S/L
Power Management Channel 2 .........................................................................422
RTC ...................................................................................................................422
A.3 CORE DOMAIN REGISTER LAYOUT ....................................................................................424
A.3.1 Module Configuration ................................................................................................424
A.3.2 Bus Interface Unit (BIU) .............................................................................................424
A.3.3 DMA Controller ..........................................................................................................424
A.3.4 General-Purpose I/O (GPIO) Port .............................................................................424
A.3.5 PS/2 Interface ............................................................................................................425
A.3.6 Core Interface ............................................................................................................425
A.3.7 Multi-Function Timer (MFT16) ...................................................................................426
A.3.8 Timing and WATCHDOG (TWD) ...............................................................................426
A.3.9 Analog to Digital Converter (ADC) .............................................................................426
A.3.10 Digital to Analog (DAC) .............................................................................................427
A.3.11 ACCESS.bus Interface (ACB) ...................................................................................427
A.3.12 Analog Comparators Monitor (ACM) .........................................................................427
A.3.13 Power Management (PM) ..........................................................................................427
A.3.14 High-Frequency Clock Generator (HFCG) ................................................................427
A.3.15 Development System Support ...................................................................................427
A.3.16 Multi-Input Wake-Up (MIWU) ....................................................................................427
A.3.17 Interrupt Control Unit (ICU) ........................................................................................428
A.3.18 Debugger Interface ....................................................................................................428
A.3.19 Pulse with Modulator (PWM) .....................................................................................429
A.3.20 Universal Synchronous/Asynchronous Receiver Transmitter (USART) ....................429
A.3.21 Flash Interface ...........................................................................................................429
A.3.22 Shared Memory Core ................................................................................................429
A.3.23 Core Access to SuperI/O ...........................................................................................430
A.3.24 MSWC .......................................................................................................................430
A.4 HOST DOMAIN REGISTER LAYOUT .....................................................................................431
Host Configuration Registers .............................................................................431
A.4.1 SuperI/O Configuration ..............................................................................................431
A.4.2 Shared Memory Configuration ...................................................................................431
A.4.3 RTC Configuration .....................................................................................................431
Host Runtime Registers .....................................................................................431
A.4.4 Shared Memory Host .................................................................................................431
A.4.5 MSWC Host ...............................................................................................................432
A.4.6 Host Interface (HI) Registers .....................................................................................432
A.4.7 RTC Registers ...........................................................................................................432
B. Software for Hardware Interface
B.1 FACTORY PARAMETERS ......................................................................................................434
B.2 PROTECTION INFORMATION ...............................................................................................435
Revision 1.07 23 www.national.com
PC87591E/S/L
1.0 Introduction
1.1 DOCUMENT ORGANIZATION
This document describes the PC87591x architecture and device specifications. It is organized as follows:
Chapter 1,Introduction, provides an overview of PC87591x modules, system connections, operating modes and configura-
tion.
Chapter 2,Signal/Pin Description and Configuration, lists the PC87591x pins and describes their functions and multiplex-
ing options.
Chapter 3,Power, Reset and Clocks, describes the PC87591x power supplies, clock scheme and reset sequence.
Chapter 4,Embedded Controller Modules, describes the modules that comprise the CompactRISC core peripherals.
Chapter 5, Host Controller Interface Modules, describes the modules and functions that interface core operation with the
host.
Chapter 6,Host-Controlled Modules and Host Interface, defines the configuration and control functions.
Chapter 7,Device Specifications, defines the AC, DC and analog characteristics of the PC87591x.
Appendix A, Summary of Registers, provides a composite listing of all relevant data on core domain registers and summa-
rizes the registers’ layouts.
Appendix B, This section includes directions for the software to handle some predetermined hardware interfaces and pro-
vides details of software-to-hardware interface conventions.
1.2 GENERAL DESCRIPTION
The PC87591x is a highly integrated, embedded controller with an embedded RISC core and system functions. Targeted
for a wide range of portable applications that use the Low Pin Count (LPC) interface, it also features a security system and
host BIOS firmware.
1.2.1 System Connections
Figure 1 shows the system connections of the PC87591x in a typical mobile PC application. The PC87591x requires little, if
any, system glue elements. For a typical application, the PC87591x includes all required memory and peripherals on-chip.
For more complex applications, it allows simple low-cost expansion, using its bus. Some of the features illustrated are mu-
tually exclusive, depending on pin functions.
The major elements of the PC87591x are:
Embedded Controller (EC) functions, which include: PS/2 devices, keyboard matrix, ACCESS.bus, timers, D/A and
A/D converters and GPIO pins that can be assigned to various functions, as needed. External memory and peripheral
devices may be added to extend the functionality of the on-chip resources.
Host Processor interface based on the LPC bus and additional signals for interrupts and system power management
Power Supplies for Host interface functions, EC and backup battery
Clocks, using a 32.768 KHz crystal and optional clock output
Strap inputs to initialize the PC87591x to different operation modes
In addition to the wide range of internal peripherals, the PC87591x provides hooks so that the system can be expanded in
an easy and cost-effective manner, as follows:
I/O expansion to support additional I/O port pins, using low-cost, standard 74HCxx devices or ASICs
On-chip memories may be expanded to interface with external RAM, flash or ROM devices (176-pin package only).
1.2.2 Power Management
The PC87591x has an advanced power management scheme controlled by the host and/or the PC87591x firmware. The
supported SuperI/O functions may be controlled directly by the host, using ACPI compliant schemes. The EC may also in-
terface with the host via one or two communication channels. Power Management events are available for ACPI-compliant
operation with the respective parts of the host chipset.
The PC87591x is designed to operate as the embedded controller of an ACPI-compliant system. It is equipped with various
system power monitor and control functions and advanced means to control its own power consumption and power modes.
ACPI-compliant wake-up and sleep control is integrated into the PC87591x. These functions are powered by VCC.
1.0 Introduction (Continued)
www.national.com 24 Revision1.07
PC87591E/S/L
or
Clock
Expansion
Memory
Host System Bus (LPC Compatible)
32KX1/32KCLKIN
32KX2
LFRAME
LAD0-3
LDRQ
SERIRQ
PWUREQ
RD
WR0, WR1*
SEL0*
A19-8*
D15-8*
AD7-0
DA3-0
IOPA7-0
IOPB7-0
IOPC7-1
IOPD7-4,3-0
RESET-2
RTC
Battery VBAT
Crystal
32.768 KHz
SRAM or
Flash
ENV0
AVCC
AGND
VDD, VCC
GND
Power
Supply
SCL1-2
D7-0
SMI
LPCPD IOPH7-0
IOPE7-0
IOPF7-0
IOPI7-0
CLKRUN
LCLK
EXWINTn
PFAIL
RI1-2, RING
SHBM
I/O
Expansion
TA1-2
BADDR0-1
TRIS
IOPC0
SELIO
SDA1-2
TB1-2
SWIN
Analog/
System
ENV1
NC
NC
Figure 1. PC87591x System Connection Diagram, 128-Pin and 176-Pin Packages
ADC
DAC
Functions
that use:
GPIO
Timers
Interrupts
Ring Wake-Up
On Control
Configuration
Inputs
(Power-Up)
Digital
32KOUT/CLKOUT/CLK
Diode
DP
DN
PWM7-0
On Switch
IOPJ7-2*
IOPK7-0*
URXD, UTXD, USCLK USART I/F
A7-0
CPU/Remote
PC87591x
Key:
*= Available only in
176-pin package
ACCESS.bus
PSCLK1
PSDAT1
External Keyboard
PSCLK2
PSDAT2
PSCLK3
PSDAT3
External Mouse Auxiliary PS/2
Interface
Interface
Interface
PSCLK4
PSDAT4
ECSCI
KBRST
KBSOUT15-0
KBSIN7-0
Internal
Keyboard
Matrix
GA20
(Optional
in ‘E’& ‘S’)
IOPL4-0*
IOPM7-0*
IOPJ1-0
1.0 Introduction (Continued)
Revision 1.07 25 www.national.com
PC87591E/S/L
The Keyboard Controller and the EC functions (core and associated peripherals) are powered by VCC, which remains active
as long as the system has a power source (e.g., main battery or outlet). Using VCC, the core may be programed to monitor
and control the system even when the host processor is turned off. To support this, the PC87591x is equipped with advanced
means to control its power consumption: software controlled clock frequency throttling, the ability to disable modules, and
four power modes. These power modes include:
Active Mode - Full functionality
Active Mode Executing WAIT Instruction - Core execution and associated operations (such as memory access) are suspended
Idle - Main clock is stopped, but the device can be woken up by internal or external events. The system tick timer is
still operational and can be used to periodically wake up the device.
Power Off - VCC is absent and only backup battery is available to supply the Real Time Clock (RTC) and retain the
state of some memory and configuration elements.
1.2.3 Operating Environments
The PC87591x can operate in one of the following four environments:
Internal ROM Enabled (IRE). Used while the PC87591x operates in the production system and executes the appli-
cation. The on-chip flash or ROM is the main source of code for the device.
On-Board Development (OBD). Used to debug the PC87591x code while it is mounted on its final production board.
All pins have their IRE functionality. Interface to a debugger (running on the host) is through the JTAG-based debug-
ger interface. OBD environment is binary and cycle-by-cycle compatible with IRE environment.
Development (DEV). Used in Application Development Boards (ADB) or In System Emulators (ISE). In this environ-
ment, the on-chip flash or ROM is replaced with off-chip SRAM memory to allow flexible and fast development of ap-
plication code. Some pins are allocated to development system use, and the GPIO functions associated with them
are replicated using off-chip logic as part of the ADB system. DEV environment is binary and cycle-by-cycle compat-
ible with OBD and IRE environments.
Programing (PROG). Used to program the on-chip flash in parallel programers. No other operation is possible in this
environment.
1.3 INTERNAL ARCHITECTURE
The PC87591x consists of several main components divided into three groups:
Core Domain
CR16B core processing unit
Bus Interface Unit and Memory Controller (BIU)
RAM and flash memory
Core peripherals
Host Domain
Host-Controlled functions
Host Interface
Host-Controller Interface
The descriptions below detail the functions of the various blocks shown in Figure 2.
1.0 Introduction (Continued)
www.national.com 26 Revision1.07
PC87591E/S/L
Figure 2. PC87591x Functional Block Diagram
1.3.1 Processing Unit
The CompactRISC CR16B core (referred to in this datasheet as the “core”) is an advanced, general-purpose 16-bit micro-
processor core with a RISC architecture. The core is responsible for arithmetic and logic operations, as well as program
control.
For more details about the core structure and instruction set, see CR16B Programmer’s Reference Manual, Revision 2.2,
September 1999 (Literature Number: 633150-001)
1.3.2 Bus Interface Unit and Memory Controller (BIU)
The BIU enables access to off-chip memory and I/O devices. It is organized in zones, as follows:
Zone 0 - Expansion Memory (flash and/or SRAM). This memory may be used for the core code, data and/or the host
BIOS program.
Zone 1 - This zone is available for off-chip in DEV environment only and is used for emulating the operation of the
off-chip base memory, using an off-chip SRAM. In IRE and OBD environments, the configuration of this zone should
be the same as in DEV environment to enable cycle-by-cycle compatibility.
The Base memory is partitioned into two zones, fast and slow. The access time to the fast zone is defined by the con-
figuration registers of Zone 1 in the BIU. The access time to the slow zone is defined by the configuration registers of
Zone 2 in the BIU. Only one chip select signal is used—the AND of the two BIU select outputs.
I/O Zone - This zone can be used for I/O expansion. In DEV environment, it can be used to recreate GPIO signals,
whose pins are used for the development system interface.
Configuration registers that control the bus transactions are associated with each zone and are part of the BIU module, See
Section 4.1 on page 69 for details. For details about the link between DEV environment and the BIU, see Section 1.4.3 on
page 30.
1.3.3 On-Chip Memory
RAM. The 2048/4096-byte on-chip RAM is mostly used for the storage of program variables and the stack. It can also store
short programs used while the flash memory is being updated. Part of the on-chip RAM is reserved for use by the core de-
velopment tools monitor program, TMON. For information, see the CompactRISCPC87591x Tmonlib Version 3.1.2.3 Re-
lease Letter, March 2001,
Flash. The PC87591E and PC87591S are equipped with a large on-chip flash. This flash includes a main block and an in-
formation block. The flash main block is also referred to as on-chip Base Memory and may be used to store core code and
constant data.
Core Bus
Peripheral Bus
Bus
KBC + PM
Host I/F
RTC
Processing
Unit
RAM
External
BIU
CR16B Core
32.768 KHz
ICU
HFCG
PMC
ADC
ACB
GPIO WDG
FLASH or ROM
MIWU
Memory + I/O
MFT16
Timer +
Adapter
PS/2
I/F
(X2)
CLK DAC
(X2)
Memory
Debugger
I/F
Shared mem.
+ Security
LPC
I/F Serial
IRQ SMI
Functions
Internal Bus
CR Access
DMA
JTAG
KBSCAN +
ACM USART
Peripherals
LPC Bus I/F
I/F Functions
PWM
Reset &
Config
MSWC
Bridge
Controlled
Host
1.0 Introduction (Continued)
Revision 1.07 27 www.national.com
PC87591E/S/L
The PC87591x hardware arbitrates flash usage by the core firmware and the host processor BIOS program when Shared-
BIOS configuration is selected. Flash sharing is based on in-parallel “cycle stealing” so both the host processor and the core
can execute code in parallel from the same memory device. The host processor typically copies the flash contents to the
host’s main memory (DRAM) on system boot to improve access time to it and enable execution when the flash’s contents
is compressed. It is important to do this early in the boot process to reduce resource contention between the core and the
host.
The PC87591E and PC87591S flash memory may be updated by the core firmware, host software, JTAG protocol or via the
parallel interface. Protection mechanisms limit the read, write and erase rights of various sources to guarantee flash content
integrity and confidentiality, where applicable. See Section 4.16.6 on page 226 for more details about the flash update and
protection mechanisms.
In DEV environment, access to the main block of the flash is disabled and replaced by off-chip SRAM to enable easy and
efficient debugging. For operation in OBD environment, the application should be linked with the TMON program and loaded
into the on-chip flash. See the CompactRISCPC87591x Tmonlib Version 3.1.2.3 Release Letter, March 2001, for infor-
mation on TMON program integration and specification of requirements.
The PC87591L is equipped with a small pre-programed flash, which functions as a boot ROM. The devices are shipped pre-
programed and may not be programed in the field. Some devices intended for development purpose may be programed via
the JTAG interface.
The information block of the flash has two dedicated areas: one for factory parameters and another for the protection word.
The factory parameters are saved during the device production and are used for various calibrations (see Appendix B.1 on
page 434 for the factory parameters block organization and usage). The protection word holds information on access rights
to the flash and the size of the core and host boot blocks. See Section 4.16.6 on page 226 and Appendix B.2 on page 435
for more information.
1.3.4 Peripherals
The ICU (Interrupt Control Unit) collects interrupts from various internal and external (through the MIWU) sources and no-
tifies the core of the event using the vectored interrupt mechanism. It supports 31 maskable interrupt inputs (see Table 16
on page 99 for the interrupt assignment) and a non-maskable interrupt (NMI) through the PFAIL input.
The MIWU (Multi-Input Wake-Up) module enables collecting various internal and external interrupt sources (events), gen-
erates interrupts in Active mode and enables the PC87591x to return from Idle mode to Active mode. The core can individ-
ually enable or disable the various wake-up conditions. The PC87591x has a total of 28 wake-up signals, some of which are
grouped to generate a single interrupt signal to the ICU.
The PMC (Power Management Controller) controls PC87591x power consumption according to the required activity level.
Power consumption is adjusted by controlling the clock frequency and selective enabling/disabling of three power modes:
Active, Idle and Power Off. Activity can be resumed by external events (through the MIWU) or internal events, such as a
periodic wake-up.
The Clock Generator provides clocks for the various core-related on-chip modules. These clocks are generated directly
from a 32.768 KHz crystal or from the on-chip High-Frequency Clock Generator (HFCG). The HFCG generates the high-
frequency clock using the RTC’s 32.768 KHz clock signal as a reference. The PC87591x operation frequency is set by pro-
graming the HFCG registers. The PMC enables and disables high-frequency clock generation, according to the required
power mode.
The GPIO Ports (General-Purpose Input/Output) module consists of up to 117 GPIO signals (84 in the 128-pin package)
that provide interface and control for the PC system. Some of these I/O port signals share their pins with an alternate function
(see Table 8 on page 54) and may be mutually exclusive. When configured as inputs, some of these signals can interrupt
the core when an event is detected, even if the device is in Idle mode. An example is the SWIN input, which is dedicated to
the PC On/Off switch.
Internal keyboard scanning is supported by 16 open-drain output signals and eight input signals. Switch-based keyboard
matrices are supported with CMOS Schmitt trigger inputs with internal pull-up resistors. Resistive keyboard matrices are
supported with analog comparator inputs with variable thresholds and optional internal pull-up resistors. Section 4.14 on
page 208 describes the functionality of the analog comparator (ACM) circuitry. For power efficiency, the inputs include an
interrupt and a wake-up capability, so that pressing/releasing keys may be identified without scanning the keyboard matrix
in either Active or Idle modes. The keyboard interrupt is controlled by the MIWU.
The PS/2 Interface enables interface with industry-standard, PS/2-compatible keyboard, mouse and other pointing devic-
es. The PC87591x supports up to four PS/2 devices via its dedicated 4-channel PS/2 interface module. Each channel has
two quasi-bidirectional signals. The symmetric structure of the channels enables software-controlled interchanging of devic-
es to channels.
The PC87591x includes a hardware accelerator, which allows the PS/2 channels to be controlled with minimal software
overhead. It also eliminates the sensitivity to interrupt latency that characterized traditional solutions.
1.0 Introduction (Continued)
www.national.com 28 Revision1.07
PC87591E/S/L
The ACB Interface is a two-wire serial interface compatible with the ACCESS.bus physical layer. It is also compatible with
Intel’s SMBus and Philips’ I2C. This module can serve as a bus master or slave and performs both transmit or receive op-
erations. As a slave, it can respond to two assigned addresses, a global call address and an SMBus ARP address.
The PC87591x includes two ACB Interface modules to allow operation on two isolated buses in the system.
The USART (Universal Synchronous Asynchronous Receiver Transmitter) gives full-duplex support for a wide range of
software programmable baud rates and data formats. It handles automatic parity generation and several error detection
schemes. It also supports DMA transfers to allow for fast processor-independent receive and transmit. It implements flow
control logic to provide the capability for hardware handshaking.
The MFT16 (Multi-Function 16-Bit Timer) contains two 16-bit timers with a range of operation modes. These timers can op-
erate, using several clock sources, in PWM, Capture or Counter mode to satisfy a wide range of application requirements.
The PC87591x includes two MFT16 modules, each of which may be assigned to functions and configured independently.
The TWD (Timer and WATCHDOG) module has a 16-bit periodic interrupt timer that can be programed to generate inter-
rupts at pre-defined intervals and an 8-bit WATCHDOG timer that can reset the PC87591x whenever the software loses
control of the processor.
The periodic timer is typically used as a system tick timer. This timer is fed by the 32.768 KHz clock. Thus its counting is not
impacted by the setting of the HFCG, and it may continue to operate even in Idle mode. This enables it to serve as a periodic
wake-up source during Idle mode.
The PWM (Pulse Width Modulator) module provides eight modulated outputs. The output signals have the same program-
mable frequency and individually-controlled duty cycles.
The ADC (Analog to Digital Converter) provides the PC87591x with an accurate means for measuring slow changing volt-
ages and temperature. The ADC module can measure up to ten external and four internal voltages with 10-bit resolution
over a voltage range of 0 to 2.97V. It can measure temperature using thermistors or perform diode-based temperature mea-
surement. Special circuits are provided to allow accurate measurement of temperature, based on the voltage drop on the
diode junction. This technique is tuned for measuring the temperature of processors with an internal diode.
The DAC (Digital to Analog Converter) has four channels of voltage output. Each of the four DAC channels has an 8-bit res-
olution with a full output range from AGND to AVCC. The DAC provides a settling time of about 1 µs on a 50 pF load.
The Debugger Interface module provides a JTAG-based interface to a remote, host-based debugger. This interface en-
ables device debugging while in OBD environment (i.e., in the final production board) or in DEV environment once in the
development system. The Debugger Interface module uses the JTAG interface to enable programing of the on-chip flash in
both these environments.
1.3.5 Host-Controller Interface Modules
Chapter 5 on page 277 describes a set of modules that resides in the boundary between the host-controlled functions and
the core-controlled functions. These modules are used for message communication, data exchange, memory access and
generating power management events to the host. Chapter 5 also discusses the mechanism that enables the core to access
the host-controlled peripherals.
The Keyboard Controller, Power Management module has three channels that are available for keyboard and power
management (EC)-related host-controller communication.
The keyboard and mouse data channel (i.e., host legacy I/O addresses 6016 and 6416) is compatible with the legacy inter-
face of keyboard controllers. It may be used with polling or interrupts. For use with interrupts, the module can generate the
two legacy IRQ signals: IRQ1 and IRQ12. In addition, the PC87591x generates the gate A20 control signal (GA20 pin) and
a soft reset signal (KBRST pin) to the host. Optionally, this KBRST reset signal can be used to prevent the host from ac-
cessing the shared flash when the PC87591x cannot perform the shared memory access during PC87591x boot-up. See
“GA20 Pin Functionality” on page 322 and “Host Keyboard Fast Reset” on page 322 for details).
The PC87591x supports three Power Management channels, compliant with ACPI requirements for Embedded Controller
(EC) interface. This enables the PC87591x to implement an EC interface that operates in either shared or private modes.
The number of Power Management channels in use and the addresses they respond to (i.e., legacy host I/O addresses 6216
and 6616) are configured in the Host Controlled Functions configuration space. These channels may generate IRQ, SMI or
SCI events to the host. The Power Management channels include a PC87570-compatible mode and an enhanced scheme
that enables more efficient control by the core.
Shared Memory and Security is supported between the host and the core. This sharing may be used for the support of a
shared BIOS scheme, secured information storage and/or for the PC87591x firmware update by the host. The base memory
of the PC87591x and, if needed, the expansion memory can be used as shared memory. The use of the Expansion memory
is optional. The Shared Memory module provides means for the host to access the shared memory. It can also secure ac-
cess to portions of the shared memory for read and/or write operations to allow reliable and tamper-protected storage and
secured update. In addition (PC87591S only), this module includes a random number generator (RNG) that provides hard-
ware-generated random numbers to the core.
1.0 Introduction (Continued)
Revision 1.07 29 www.national.com
PC87591E/S/L
The Mobile System Wake-Up module includes various system wake-up and power management services that may be
handled either by the host or the core. ¨(wake-upsources may be the RTC or external events such as ring detection on the
RING input or modem RI inputs. The module provides hooks for ACPI-compliant drivers, which enable the drivers to handle
wake-up events, change the system power state (including turning it off) and interface to the core firmware. Mask bits can
be enabled to determine whether the core or the host handles each one of the events. In addition, this module provides sta-
tus information about the host domain (e.g., reset input state and VDD supply status).
The Core Access to Host-Controlled Peripherals module enables core access to SuperI/O modules. It can interleave us-
age of a module with the host or take control of it and prevent any host access to that module.
1.3.6 Host-Controlled SuperI/O Modules and Host Interface
The Host Interface is based on Intel’s Low Pin Count (LPC) interface, as defined in LPC Interface Specification, Revision
1.0. This interface enables the host to perform read and write cycles using I/O space accesses and memory space accesses
and FWH transactions. Interrupts are sent to the host, using the serial IRQ protocol.
The PC87591x supports the advanced power management features of the LPC bus. The SMI signal may be sent to interrupt
the host and put it in System Management Mode (SMM). The PWUREQ signal may be connected to one of the wake-up
inputs of the host chipset and used to trigger an SCI event for various EC communication purposes. The PC87591x can
operate with a slowed down or stopped LPC clock and can re-start the LPC clock as part of the system power management
capabilities, using the CLKRUN signal. The LPCPD input enables turning off LPC bus supply while the PC87591x and some
Host Controlled functions are operating.
Host Configuration. The PC87591x includes seven logical devices, each with associated configuration registers, in addi-
tion to a set of global configuration registers.
The central configuration register set supports ACPI-compliant PnP configuration. The configuration registers are structured
as a subset of the Plug and Play Standard registers defined in Appendix A of the Plug and Play ISA Specification, Revision
1.0a by Intel and Microsoft. All system resources assigned to the functional blocks (I/O address space and IRQ lines) are
configured in and managed by the central configuration register set. In addition, some function-specific parameters are con-
figurable through the configuration registers and distributed to the functional blocks through special control signals.
The RTC (Real Time Clock) has a low-power timekeeping mechanism that provides a time-of-day, year-2000-compatible
calendar with a century counter and alarm features. It can work from either VCC or a backup battery, using an internal switch.
Other features include three maskable interrupt sources and 242 bytes of general-purpose RAM. An external battery source
maintains valid RAM and time during VCC failure. The RTC is software compatible with the DS1287 and MC146818.
1.4 OPERATING ENVIRONMENTS
On power-up reset, the ENV1-0 and TRIS input signals select one of the following operating environments:
Internal ROM Enabled (IRE)
On Board Development (OBD)
Development (DEV)
Programing (PROG)
See Section 2.3 on page 53 for more information about these pins and controlling the loads connected to them.
Code written for IRE environment is executable in all environments, since it is binary compatible. The execution time of code
in on-chip Base Memory (in IRE environment) is identical to that in OBD and DEV environments; i.e., the operation is cycle-
by-cycle compatible.
PC87591x devices are tested to ensure that they operate in either IRE or OBD environment. Only selected parts are tested
for operation in DEV environment.
1.4.1 IRE Environment
IRE environment is used while the PC87591x operates in the production system and executes the application. The on-chip
flash (ROM in PC87591L) is the main source of code for the device. In this environment, after reset, the PC87591x starts
running the code written in the internal flash first address, which is part of the flash’s core boot block. In PC87591E and
PC87591S the core boot-code size may vary from 4 Kbytes to128 Kbytes, as defined in the protection word. To prevent ex-
ecution from non-programed flash (typically due to interrupted update), the code in the boot sector should verify the validity
of the information in other parts of the flash. Once this is successfully done, the core may start executing from these parts
as well. The External Memory, if available, can also be used to store code and/or data.
The PC87591L is shipped with 4 Kbytes of on-chip boot code. The user is expected to use an external memory for most of
the code and constant data.
To maximize on-chip flash (ROM) performance, configure the BIU as described in Section 4.1.11 on page 86 and
Section 4.16.2 on page 219.
1.0 Introduction (Continued)
www.national.com 30 Revision1.07
PC87591E/S/L
See Figure 1 on page 24 for a system example in IRE environment. In this environment, the ENV0, ENV1 and TRIS strap
pins do not need any external pull-up resistors.
1.4.2 OBD Environment
OBD environment is used for debugging the PC87591x firmware while it is mounted on its final production board. All pins
have their IRE functionality, and the interface to a debugger running on the host is enabled using the JTAG based debugger
interface. In OBD Environment, code is executed from the on-chip flash memory. Breakpoints on data and code access may
be applied using the core hardware breakpoint mechanism. The monitor stored in the on-chip flash is used as part of the
debugging environment. Erasing and reprograming the flash is enabled through the JTAG-based debugger interface.
OBD environment is binary and cycle-by-cycle compatible with IRE environment.
See Figure 3 on page 31 for a system example in OBD environment. In this environment, the ENV0 and TRIS strap pins are
left unconnected, and ENV1 requires an external pull-up resistor. If the flash Contents Protect bit in the protection word is
cleared (0), the PC87591x remains reset until the bit is set; see Section 4.16.6 on page 226.
1.4.3 DEV Environment
DEV environment is used in Application Development Boards (ADBs) or In System Emulators (ISEs). It may only be used
when the chip is packed in its 176-pin package. In this mode, the on-chip flash is replaced with off-chip SRAM memory to
allow flexible and fast development of application code. Some pins are allocated for development system use, and the GPIO
functions associated with the pins are replicated using off-chip logic as part of the ADB system. DEV environment is binary
and cycle-by-cycle compatible with OBD and IRE environments.
In this environment, the pins of ports PH, PI, PJ, PK, PL and PM are allocated for the interface to the off-chip Base Memory,
core status signals, reset output and a breakpoint input. The system may regain these ports using the I/O Expansion protocol
and off-chip logic, while maintaining cycle-by-cycle and binary compatibility with IRE and OBD environments. Using the
same software, this environment is binary and cycle-by-cycle compatible with IRE and OBD environments. All features of
IRE environment can be implemented either directly or by using additional external logic.
See Figure 4 on page 32 for a system example in DEV environment. In this environment, the ENV0 strap pin needs an ex-
ternal pull-up resistor and the ENV1 and TRIS pins are left unconnected. If the flash Contents Protect bit in the protection
word is cleared (0), the PC87591x remains reset until the bit is set; see Section 4.16.6 on page 226.
1.4.4 PROG Environment
PROG environment is used to program the on-chip flash. It can be used to program the on-chip flash with an external flash
programer. In PROG environment, the PC87591x remains reset indefinitely, I/O pins are allocated for the on-chip flash in-
terface ports and the on-chip flash interface is accessible directly through the I/O pins.
In this environment, both ENV0 and ENV1 strap pins need an external pull-up resistor. The TRIS pin can be either left un-
connected or connected to a pull-down resistor.
1.5 MEMORY MAP
ThePC87591xhas two address domains: core and host. The host address space is composed of the host I/O address space
and the host memory space. Section 1.5.1 discusses the mapping of memories and peripherals into the core address space.
Figure 5 illustrates the memory map and the shared access schemes that are possible. Section 1.5.2 discusses the mapping
of the host address space and ways of accessing it. The PC87591x enables several memories in the core address space
to have restricted access to the host. These memories are referred to as “shared memory” or “shared BIOS”. In addition, the
core can access the Host Controlled Functions. Section 1.5.2 and Section 1.5.3 discuss these instances of cross-domain
access, respectively.
1.0 Introduction (Continued)
Revision 1.07 31 www.national.com
PC87591E/S/L
TCK
TMS
ENV0
ENV1
NC
VCC R1
TDI
TDO
TINT
or
Clock
Host System Bus (LPC Compatible)
32KX1/32KCLKIN
32KX2
LFRAME
LAD0-3
LDRQ
SERIRQ
PWUREQ
RD
WR0, WR1*
SEL0*
A19-8*
D15-8*
AD7-0
DA3-0
IOPA7-0
IOPB7-0
IOPC7-1
IOPD7-4,3-0
RESET(1-2)
RTC
Battery VBAT
Crystal
32.768 KHz
AVCC
AGND
VDD, VCC
GND
Power
Supply
SCL1-2
D7-0
SMI
LPCPD IOPH7-0
IOPE7-0
IOPF7-0
IOPI7-0
CLKRUN
LCLK
EXWINTn
PFAIL
RI1-2, RING
SHBM
I/O
Expansion
TA1-2
BADDR0-1
TRIS
IOPC0
SELIO
SDA1-2
TB1-2
SWIN
Analog/
System
Figure 3. OBD Environment PC87591x System Connection Diagram, 128-Pin and 176-Pin Packages
ADC
DAC
Functions
that use:
GPIO
Timers
Interrupts
Ring Wake-Up
On Control
Configuration
Inputs
(Power-Up)
Digital
32KOUT/CLKOUT/CLK
Diode
CPU/Remote
DP
DN
PWM7-0
On Switch
IOPJ7-2*
IOPK7-0*
URXD, UTXD, USCLK USART I/F
A7-0
Key:
*= Available only in
176-pin package
JTAG I/F
Debugger
to
PC87591x
ACCESS.bus
PSCLK1
PSDAT1
External Keyboard
PSCLK2
PSDAT2
PSCLK3
PSDAT3
External Mouse Auxiliary PS/2
Interface
Interface
Interface
PSCLK4
PSDAT4
ECSCI
KBRST
KBSOUT15-0
KBSIN7-0
Internal
Keyboard
Matrix
GA20
Expansion
Memory
SRAM or
Flash
(Optional
in ‘E’& ‘S’)
IOPL4-0*
IOPM7-0*
IOPJ1-0
1.0 Introduction (Continued)
www.national.com 32 Revision1.07
PC87591E/S/L
RD
WR1-0
SEL0
A19-0
D15-8
TCK
D7-0
TMS
TDI
TDO
TINT
ENV0
ENV1
NC
VCC
R1
BRKL_RST
BST2-0
PFS
PLI
BE1,0
CBRD
RD
WR1-0
A19-0
D15-0
SELIO
SEL1
or
Clock
Host System Bus (LPC Compatible)
32KX1/32KCLKIN
LFRAME
LAD0-3
LDRQ
SERIRQ
PWUREQ
AD7-0
DA3-0
IOPA7-0
IOPB7-0
IOPC7-1
IOPD7-0
RESET(1-2)
RTC
Battery VBAT
Crystal
32.768 KHz
AVCC
AGND
VDD, VCC
GND
Power
Supply
SCL1-2
SMI
LPCPD
IOPE7-0
IOPF7-0
CLKRUN
LCLK
EXWINTn
PFAIL
RI1-2, RING
SHBM
TA1-2
TRIS
IOPC0
SDA1-2
TB1-2
SWIN
Analog/
System
Figure 4. DEV Environment PC87591x System Connection Diagram,176-Pin Package
ADC
DAC
Functions
that use:
GPIO
Timers
Interrupts
Ring Wake-Up
On Control
Configuration
Inputs
(Power-Up)
Digital
32KOUT/CLKOUT/CLK
Diode
CPU/Remote
DP
DN
PWM7-0
On switch
URXD, UTXD, USCLK USART I/F
BADDR0-1
32KX2
JTAG I/F
Debugger
to
Development
Support
I/O
Expansion
Restored
Ports
PH
PI
PJ
Off-chip
Base
(Flash emul.
using SRAM)
Memory
PK
PL
PM
NC
CLK
PC87591x
ACCESS.bus
PSCLK1
PSDAT1
External Keyboard
PSCLK2
PSDAT2
PSCLK3
PSDAT3
External Mouse Auxiliary PS/2
Interface
Interface
Interface
PSCLK4
PSDAT4
ECSCI
KBRST
KBSOUT15-0
KBSIN7-0
Internal
Keyboard
Matrix
GA20
Expansion
Memory
SRAM or
Flash
(Optional
in ‘E’& ‘S’)
1.0 Introduction (Continued)
Revision 1.07 33 www.national.com
PC87591E/S/L
1.5.1 Core Address Domain Memory Map
The memory and I/O devices are directly mapped into the 2 Mbyte address space of the core. The core address space can
include both code and data. However, access to data stored in the first 64 Kbytes of the address space is more efficient.
Most of the core code and constant data (including its boot section) is stored in the Base Memory. This memory is:
On-chip flash in IRE and OBD environments
Off-chip memories (SRAM or flash memory) in DEV environment
External memory may be added to the Base Memory to expand the amount of memory available for the application. The on-
chip RAM and various peripherals are also mapped into the core address space.
Tables 1 to 3 show how the PC87591x memory and I/O devices are mapped in the core address space. Appendix A on
page 408 shows the address map of the registers for the other modules.
Addresses not included in the following three tables or Appendix A are reserved. Attempts to access reserved addresses
produce unpredictable results.
Table 1. PC87591S Memory Map
Address Size
(Bytes) Description
Purpose Environment
00 000016 00 DFFF16 56K Base Memory IRE & OBD - Internal Flash
DEV - External Base Memory
00 E80016 00 F7FF16 4K System RAM
00 F88016 00 F8FF16 Flash Control Registers1
00 F90016 00 F90A16 11 Shared BIOS and Security Registers1
1. See Appendix A on page 408 for details of the implemented registers.
00 F98016 00 F98F16 16 BIU Registers1
00 FA0016 00 FA7F16 DMA Controller Registers11
00 FB0016 00 FBFF16 256 I/O Expansion
00 FC0016 00 FFFF16 1K On-chip Module Registers1
01 000016 01 FFFF16 64K Base Memory (cont.) IRE & OBD - Internal flash
DEV - External Base Memory
02 000016 0F FFFF16 896K Reserved IRE & OBD
Base Memory DEV - External Base Memory
10 000016 1F FFFF16 1024K Expansion Memory2
2. Available in 176-pin package only.
Figure 5. PC87591x Memory Domains
0
64K
0
4G
Mem
Space
0
2M
Core Address Domain
Host Address Domain
Host Domain Memory
Core Access to Host
End of Flash
External
Memory
Expansion
1M
I/O
Space Controlled Functions 0
2M External
Memory
Expansion
1M
4K
External
Memory
Expansion
PC87591L
PC87591E
PC87591S
(End of Core Memory
Wrap-Around 2M)
1.0 Introduction (Continued)
www.national.com 34 Revision1.07
PC87591E/S/L
Table 2. PC87591E Memory Map
Table 3. PC87591L Memory Map
Register Abbreviations and Access
The following abbreviations are used to indicate the Register Type:
R/W= Read/Write
R= The Read portion of a register, where a read from a specific address returns the value of a specific register; a
write to the same address is to a different register.
W= The Write portion of a register as described above for ‘R’.
RO= Read Only
WO= Write Only
R/W1C= Read/Write 1 to Clear. Writing 1 to a bit clears it to 0. Writing 0 has no effect.
Address Size
(Bytes) Description
Purpose Environment
00 000016 00 DFFF16 56K Base Memory IRE & OBD - Internal Flash
DEV - External Base Memory
00 F00016 00 F7FF16 2K System RAM
00 F88016 00 F8FF16 Flash Control Registers1
00 F90016 00 F90A16 11 Shared BIOS and Security Registers1
1. See Appendix A on page 408 for details of the implemented registers.
00 F98016 00 F98F16 16 BIU Registers1
00 FA0016 00 FA7F16 DMA Controller Registers11
00 FB0016 00 FBFF16 256 I/O Expansion
00 FC0016 00 FFFF16 1K On-chip Module Registers1
01 000016 0F FFFF16 960K Reserved IRE & OBD
Base Memory DEV - External Base Memory
10 000016 1F FFFF16 1024K Expansion Memory2
2. Available in 176-pin package only.
Address Size
(Bytes) Description
Purpose Environment
00 000016 00 0FFF16 4K Base Memory IRE & OBD - Internal Flash
DEV - External Base Memory
00 100016 00 DFFF16 52K Expansion Memory 1
1. The Expansion Memory size is limited to 1 Mbyte and is aliased between addresses above and
below 01 000016.
00 F00016 00 F7FF16 2K System RAM
00 F88016 00 F8FF16 Flash Control Registers1
00 F90016 00 F90A16 11 Shared BIOS and Security Registers2
2. See Appendix A on page 408 for details of the implemented registers.
00 F98016 00 F98F16 16 BIU Registers1
00 FA0016 00 FA7F16 DMA Controller Registers11
00 FB0016 00 FBFF16 256 I/O Expansion
00 FC0016 00 FFFF16 1K On-chip Module Registers1
01 000016 0F FFFF16 960K Expansion Memory
10 000016 1F FFFF16 1024K Expansion Memory
1.0 Introduction (Continued)
Revision 1.07 35 www.national.com
PC87591E/S/L
Eitherbyte-wideorword-widetransactionstoanyaddress withinthe memory address space may be used to access memory
devices.
Only byte-wide transactions may be used to access byte-wide registers, and only word-wide transactions may be used to
access word-wide registers. Attempts to read a write-only register or write to a read-only register cause unpredictable re-
sults.
Zeros must be written to reserved bits unless stated otherwise. Reading reserved bits returns an undefined value. When
modifying a register with reserved bits, the data read from reserved a bit can be written back to it.
Accessing Base Memory
In the PC87591E and PC87591S the Base memory is the main storage for code and data. When Shared BIOS is enabled,
the Base memory may also be used for storing BIOS code and data. Figure 6 on page 35 illustrates how on-chip and off-
chip Base Memory are mapped to the PC87591E and PC87591S address space.
The Base Memory is divided into two zones:
Fast Zone - for addresses with Base Memory in the range of 00 0000 to 01 FFFF. The access time to this zone is
controlled by the BIU Zone 1 configuration registers.
Slow Zone - for addresses with Base Memory in the range of 02 0000 to 0F FFFF. The access time to this zone is
controlled by the BIU Zone 2 configuration registers.
In the PC87591L, the base memory is used for storing code and data required for basic boot operations. The rest of the code
and data are stored in the Expansion Memory shared by the core firmware and host BIOS. Figure 7 on page 36 illustrates
how on-chip and off-chip Base Memory are mapped to the PC87591L address space.
IRE and OBD Environments - On-Chip Base Memory. In IRE and OBD environments, the on-chip flash (ROM) is used as
Base memory. Note that the size of the available memory may differ among members of PC87591x family (see Tables 1 to
3). The access time to it is controlled by BIU Zones 1 and 2. To allow cycle-by-cycle compatibility with DEV environment,
both zones should be programed in the same way for all environments. Thus to maximize on-chip flash (ROM) performance,
configure BIU Zones 1 and 2, as described in Section 4.1.11 on page 86 and Section 4.16 on page 218, with minimal access
time supported at the frequency in use, as defined in “Flash Read, Write and Erase Time” on page 222.
Off-Chip Base Memory. In DEV environment (when on-chip flash is disabled), the code and constant data are stored in off-
chip Base Memory. In the PC87591E and PC87591S, this off-chip Base Memory has 1016 Kbytes of address space
(00 000016 to 00 DFFF16 and 01 000016 to 0F FFFF16). In the PC87591L, the size of the off-chip Base Memory is 4 Kbytes.
To ensure that the code fits into the on-chip flash in IRE and OBD environments later on, both the code and constant data
should fit within the defined flash size, for the selected member of the PC87591x family.
0
56 K
64 K
Off-Chip Base Memory
On-Chip Base Memory
Figure 6. Base Memory Address Mapping - PC87591E and PC87591S
56 K
128K
Core Address Map 00 0000
02 0000
Zone 2
Access Time
01 FFFF
0F FFFF
Control
Zone 1
Access Time
Control
2 M
1 M
PC87591S
Flash Size
PC87591E
Flash Size
1.0 Introduction (Continued)
www.national.com 36 Revision1.07
PC87591E/S/L
Accessing Expansion Memory
Expansion Memory Configuration is available in PC87591x versions packed in 176-pin packages. Access to it is enabled
only after:
The pins used for the memory interface are configured to operate as Expansion Memory interface signals (see
Section 2.4 on page 54 for details on the alternate functions configuration).
The BIU Zone 0 Configuration register (SZCFG0), which controls the memory access parameters (e.g., bus width and
access time), is set to support the configuration in use.
The interface signals to the Expansion Memory are:
8-bit flash or SRAM: SEL0, RD, WR0, D0-7 and A0-19 (fewer address lines may be used with a smaller flash).
16-bit flash or SRAM: SEL0, RD, WR0-1, D0-15 and A1-19 (fewer address lines may be used with a smaller flash).
Figure 8 shows the External Memory Address Range mapping to the core, in the PC87591E and PC87591S devices.
Figure 9 shows the External Memory Address Range mapping to the core in the PC87591L device. Note that in PC87591L
devices, the External Memory is aliased to low addresses of the core address space, enabling access to memory locations
in the flash from both an address in the low memory and an address in the upper part of the memory.
0
4 K
64 K
Off-Chip Base Memory
On-Chip Base Memory
Figure 7. Base Memory Address Mapping - PC87591L
4 K
Core Address Map 00 0000
00 0FFF
Zone 1
Access Time
Control
PC87591L
Flash Size
2 M
1 M
1.0 Introduction (Continued)
Revision 1.07 37 www.national.com
PC87591E/S/L
External Memory Mapping into Shared BIOS Memory
When the shared BIOS memory is enabled using the SHBM strap input (SHBM=1) or the Shared Memory Configuration
Registers (LDN=10h), the Expansion Memory address range is mapped into the address range of the host. The PC87591x
uses the wrap-around effect of the core address space (on a 2 Mbyte boundary) using “growing down” addresses, which
enables the host to view the Expansion flash as a continuation of the BIOS Memory. See Section 5.3.2 on page 297 for de-
tails of the memory mapping scheme.
Accessing I/O Expansion Space
The I/O expansion protocol enables implementing I/O devices or GPIO ports in the system, in addition to those available on-
chip, for IRD, OBD and DEV environments. In addition, in DEV environment, some of the on-chip I/O port pins are used to
interface with off-chip peripherals. In such a case, the I/O expansion protocol is used to implement the functionality of these
I/O ports, using off-chip external logic. Access to these ports is through the same addresses used for the ports’ on-chip im-
plementation.
0
56 K
64 K
128 K
2 M
1 M
Core Address Map Expansion Memory Address
Figure 8. Expansion Memory (Zone 0) Address Range - PC87591E and PC87591S
1 M
0
0
4K
64 K
2 M
1 M
Core Address Map Expansion Memory Address
Figure 9. Expansion Memory (Zone 0) Address Range - PC87591L
0
1 M
1.0 Introduction (Continued)
www.national.com 38 Revision1.07
PC87591E/S/L
The I/O expansion space is mapped to the address space 00 FB0016 to 00 FBFF16. This space is partitioned as follows:
Addresses in the range 00 FB0016 to 00 FB2216 are used by GPIO ports PH, PI, PJ, PK, PL and PM (either on-chip
or in their off-chip implementation, while the chip is in DEV environment).
Address 00 FBFE16 is used only in DEV environment by the MCFGSH register and must be written after each write
to the MCFG with the same data written to the MCFG.
Addresses in the range 00 FBC016 to 00 FBFF16 are reserved for development board use.
All other addresses may be used by the application for adding additional I/O elements.
The PC87591x accesses the off-chip I/O expansion using the I/O zone of the BIU. The zone select signal (SELIO), address
lines A0-7 and the RD and WR0 signals are used to interface to the off-chip logic.
1.5.2 Host Address Domain Memory Map
The host address space includes memory space and I/O space.
The I/O space used by the PC87591x is configured through the PC87591x configuration registers. The configuration register
address is defined by strap inputs (BADDR0-1) to be one of two fixed addresses or an address defined by the core using
registers in the MSWC module.
When a Shared BIOS scheme is enabled via the SHBM strap input, the PC87591x is mapped to enable the host to boot from
a shared flash device. The PC87591x supports either memory or FWH transactions for the host memory interface, with au-
tomatic selection between them (see Section 6.1.11 on page 349). Section 5.3 on page 297 discusses the mapping of mem-
ory between the host and core domains and the read and write access protection scheme from the host and core sides.
Following the boot process, the Shared Memory configuration registers (see Section 6.1.11 on page 349) enable setting
memory sharing. The configuration setting includes defining the memory protocol in use (memory or FWH) and the address
range used in the host address space. The configuration registers allow the defaults set by the SHBM strap input to be over-
ridden; this enables using the shared memory for purposes other than system BIOS (e.g., PC87591x firmware update and
secured storage of information).
1.5.3 Core Access to Host Controlled Peripherals
The core may access host domain devices through the Core to Host Controlled Functions access bridge. The bridge em-
ploys an indirect mapping scheme.
There is only a single set of peripheral registers for host and core use. The bus arbitration guarantees that only one of the
two register accesses occurs at any given time, but this does not prevent problems that may be caused by conflicting write
transactions. When such a case is expected, the core lock mechanism may be used to protect access to one or more of the
devices. The lock may also be used to protect from the host from access to devices due to the security reasons.
The core accesses a register by specifying the logical device and the offset of the register within the logical device. Note that
the configuration registers’ index and data registers are also handled as a logical device. The core triggers a read by writing
1 to the read start bit and waits for the bit to clear; it can then read the data from the data register. The core triggers a write
by performing a write operation to the data register.
Section 5.4 on page 313 provides details of the bridge and its operation.
Revision 1.07 39 www.national.com
PC87591E/S/L
2.0 Signal/Pin Description and Configuration
2.1 CONNECTION DIAGRAMS
176-pin Low Profile Plastic Quad Flatpack (LQFP)
Order Number PC87591E-VPC / PC87591S-VPC / PC87591L-VPC
NS Package Number VPC176
85
80
75
70
65
60
55
5 101520253035
95100105110
40
115120
125
130
50
90
135
140
145
150
155
160
165
170
175
1
45
IOPE1/AD5
IOPE0/AD4
AD3
AD2
AD1
AD0
NC
NC
KBSIN7
KBSIN6
KBSIN5
KBSIN4
KBSIN3
KBSOUT15
KBSOUT14
KBSOUT13
KBSOUT12
IOPJ7/BRKL_RSTO
IOPJ6/PLI
IOPJ5/PFS
IOPJ4/BST2
IOPJ3/BST1
IOPJ2/BST0
GND
VCC
IOPK3/A11
IOPK2/A10
VCC
GND
IOPI0/D0
IOPI1/D1
IOPI2/D2
IOPI3/D3
IOPK1/A9
IOPK0/A8
IOPI4/D4
IOPI5/D5
IOPI6/D6
IOPI7/D7
IOPM0/D8
IOPM1/D9
IOPJ1/WR0
IOPJ0/RD
IOPM2/D10
IOPM3/D11
32KX1/32KCLKIN
GND
32KX2
VBAT
IOPB0/URXD
IOPB1/UTXD
IOPB2/USCLK
IOPB3/SCL1
IOPB4/SDA1
VCC
GND
CLK
IOPC1/SCL2
IOPC2/SDA2
VCC
IOPB7/RING/PFAIL/RESET2
IOPH1/A1/ENV1
IOPH2/A2/BADDR0
IOPH3/A3/BADDR1
IOPH4/A4/TRIS
IOPH5/A5/SHBM
IOPH6/A6
IOPH7/A7
IOPK4/A12
IOPK5/A13_BE0
VCC
GND
IOPF7/PSDAT4
IOPF6/PSCLK4
IOPK6/A14_BE1
IOPK7/A15_CBRD
IOPF5/PSDAT3
IOPF4/PSCLK3
IOPF3/PSDAT2
IOPF2/PSCLK2
IOPL0/A16
IOPL1/A17
IOPF1/PSDAT1
IOPF0/PSCLK1
TMS
TDO
TINT
TCK
IOPL2/A18
IOPL3/A19
DA3
DA2
DA1
DA0
NC
NC
AGND
AVCC
DN/AD9
DP/AD8
IOPE3/AD7
IOPE2/AD6
NC
NC
SEL0
SEL1
IOPL4/WR1
IOPC0
IOPC3/TA1
IOPC5/TA2
IOPC4/TB1/EXWINT22
IOPD6
IOPD7
IOPC6/TB2/EXWINT23
SELIO
IOPH0/A0/ENV0
KBSIN2
TDI
KBSOUT0
KBSOUT1
KBSOUT2
KBSOUT3
KBSOUT4
KBSOUT5
KBSOUT6
KBSOUT7
KBSOUT8
KBSOUT9
KBSOUT10
KBSOUT11
KBSIN0
KBSIN1
PC87591x
176-pin LQFP
(Top View)
NC
IOPM4/D12
IOPM5/D13
IOPM6/D14
IOPE4/SWIN
IOPE6/LPCPD/EXWINT45
LCLK
RESET1
SERIRQ
LDRQ
LFRAME
VDD
GND
LAD3
LAD2
LAD1
LAD0
SMI
PWUREQ
IOPB6/KBRST
NC
NC
IOPD4
IOPD5
VCC
GND
IOPC7/CLKOUT
IOPM7/D15
IOPE7/CLKRUN/EXWINT46
IOPD0/RI1/EXWINT20
NC
IOPE5/EXWINT40
IOPD1/RI2/EXWINT21
IOPD2/EXWINT24/RESET2
IOPD3/ECSCI
IOPA0/PWM0
IOPA1/PWM1
IOPA2/PWM2
IOPA6/PWM6
IOPA3/PWM3
IOPA5/PWM5
IOPA4/PWM4
IOPA7/PWM7
IOPB5/(GA20)
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 40 Revision1.07
PC87591E/S/L
128-pin LQFP Package
Order Number: PC87591E-VLB / PC87591S-VLB
NS Package Number VLB128
IOPE4/SWIN
IOPE6/LPCPD/EXWINT45
LCLK
RESET1
SERIRQ
LDRQ
LFRAME
VDD
GND
LAD3
LAD2
LAD1
LAD0
SMI
PWUREQ
IOPB6/KBRST
IOPB5/(GA20)
IOPC7/CLKOUT
IOPE7/CLKRUN/EXWINT46
IOPD0/RI1/EXWINT20
GND
VCC
IOPE1/AD5
IOPE0/AD4
AD3
AD2
AD1
AD0
IOPH1/A1/ENV1
IOPH2/A2/BADDR0
IOPH3/A3/BADDR1
IOPH4/A4/TRIS
IOPH5/A5/SHBM
IOPH6/A6
VCC
GND
IOPF7/PSDAT4
IOPF6/PSCLK4
IOPF5/PSDAT3
IOPF4/PSCLK3
IOPF3/PSDAT2
IOPF2/PSCLK2
IOPF1/PSDAT1
IOPF0/PSCLK1
TMS
TDO
TINT
TCK
DA3
DA2
DA1
DA0
AGND
AVCC
DN/AD9
DP/AD8
IOPE3/AD7
IOPE2/AD6
IOPH0/A0/ENV0
TDI PC87591x
128-pin LQFP
(Top View)
1
5
10
15
20
25
30
110
115
120
125
55
50
45
40
60
65
70
75
80
85
90
95
100
105
35
VCC
GND
IOPI0/D0
IOPI1/D1
IOPI2/D2
IOPI3/D3
IOPI4/D4
IOPI5/D5
IOPI6/D6
IOPI7/D7
IOPJ1/WR0
IOPJ0/RD
32KX1/32KCLKIN
GND
32KX2
VBAT
IOPB0/URXD
IOPB1/UTXD
IOPB2/USCLK
IOPB3/SCL1
IOPB4/SDA1
IOPC1/SCL2
IOPC2/SDA2
VCC
IOPB7/RING/PFAIL/RESET2
IOPH7/A7
IOPC0
IOPC3/TA1
IOPC5/TA2
IOPC4/TB1/EXWINT22
IOPC6/TB2/EXWINT23
SELIO
IOPE5/EXWINT40
KBSOUT11
KBSOUT0
KBSOUT1
KBSOUT10
KBSOUT9
KBSOUT8
KBSOUT7
KBSOUT6
KBSOUT5
KBSOUT4
KBSOUT3
KBSOUT2
IOPA7/PWM7
IOPA6/PWM6
IOPA5/PWM5
IOPA4/PWM4
IOPA3/PWM3
IOPA2/PWM2
IOPA1/PWM1
IOPA0/PWM0
IOPD3/ECSCI
IOPD2/EXWINT24/RESET2
IOPD1/RI2/EXWINT21
KBSIN0
KBSIN1
KBSIN2
KBSIN3
KBSIN4
KBSIN5
KBSIN6
KBSIN7
KBSOUT15
KBSOUT14
KBSOUT13
KBSOUT12
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 41 www.national.com
PC87591E/S/L
2.2 BUFFER TYPES AND SIGNAL/PIN DIRECTORY
The following sections contain detailed functional descriptions and electrical DC characteristics for the PC87591x signals.
The pin multiplexing and function selection criteria are described in Section 2.4 on page 54. The signal DC characteristics
are denoted by a buffer type symbol described briefly below and in further detail in Section 7.2 on page 374. The pin multi-
plexing information refers to two different types of multiplexing:
MUX - Multiplexed, denoted by a slash (/) between pins in the diagram in Section 2.1 on page 39. Pins are shared
between two different functions. Each function is associated with different board connectivity. Normally, the function
selection is determined by the board design and can not be changed dynamically. The multiplexing options must be
configured by the core in order to comply with the board implementation.
MM - Multiple Mode, denoted by an underscore (_) between pins in the diagram in Section 2.1 on page 39. Pins have
two or more modes of operation within the same function. These modes are associated with the same external
(board) connectivity. Mode selection may be controlled by the device driver through the registers of the functional
block and do not require a special setup. These pins are not considered multiplexed pins from the configuration per-
spective. The mode selection method as well as the signal specification in each mode are described in the functional
description.
Table 4. Buffer Types
Symbol Description
INAC Input, analog to ACM
INAD Input, analog to ADC
INCS Input, CMOS compatible, with Schmitt Trigger
INDI Input, analog from remote diode
INOSC Input, from crystal oscillator (not characterized)
INPCI Input, PCI 3.3V
INSM Input, SMBus compatible
INTInput, TTL compatible
INTS Input, TTL compatible, with Schmitt Trigger
INULR Input, power, resistor protected (not characterized)
Op/n Output, push-pull output buffer that is capable of sourcing pmA and sinking
nmA
ODnOutput, open-drain output buffer that is capable of sinking nmA
ODA Output, analog from DAC
ODI Output, analog to remote diode
OOSC Output, to crystal oscillator (not characterized)
OPCI Output, PCI 3.3V
PWR Power pin
GND Ground pin
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 42 Revision1.07
PC87591E/S/L
2.2.1 ACCESS.bus (ACB1 and ACB2) Interface
2.2.2 Analog Interface
2.2.3 Clocks
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
SCL2-1 125,
121 169,
163 I/O INSM/OD2VCC ACCESS.bus Serial Clock 1 and 2 Signals.
An internal pull-up for this pin is optional.
SDA2-1 126,
122 170,
164 I/O INSM/OD2VCC ACCESS.bus Serial Data 1 and 2 Signals.An
internal pull-up for this pin is optional.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
AD9-0 70-61 94-93,
90-87,
84-81
IIN
AD AVCC Analog to Digital Converter Inputs.
DA3-0 76-73 102-99 O ODA AVCC Digital to Analog Converter Outputs.
DP 69 93 O ODI AVCC Diode Anode. Remote diode current source.
Connected to remote discrete diode.
DN 70 94 I INDI AVCC Diode Cathode. Remote diode current sink.
Connected to remote discrete diode. Must be
grounded when not used.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
32KCLKIN 116 158 I INTVPP 32.768 KHz Clock Input.
32KX1 116 158 I INOSC VPP 32.768 KHz Crystal Oscillator Input. Input
from external crystal oscillator circuitry. See
Figure 113 on page 356.
32KX2 118 160 O OOSC VPP 32.768 KHz Crystal Oscillator Output. Output
to external crystal oscillator circuitry. See
Figure 113 on page 356.
CLK N/A 47 O O1/2 VCC Clock Output. PC87591x Core Domain system
clock. Available in all environments, in the
176-pin package option.
CLKOUT 3 1 O O2/4 VCC Clock Output. This pin may output either the
32.768 KHz clock or the Core Domain system
clock (CLK). CLKM bit in MCFG register
selects the output clock frequency.
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 43 www.national.com
PC87591E/S/L
2.2.4 Core Bus Interface Unit (BIU)
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
A3-0 95-92 127-124 O O1/2 VCC Address Bus, bits 0-19. Core external address
bus. Affected or used by any transaction on the
internal core-bus, including DMA transactions
and accesses to the internal memory.
A19-8 N/A 103-104
112-113
120-121
129-130
134-135
142-143
A7-4 99-96 133-131,
128 OO
2/12 VCC
D7-4,
D3-0 109-
102 147-144
141-138 I/O INT/O1/2 VCC Data bus, bits 0-15. Core external data bus.
Used for core access to external memory or I/O
devices. When accessing an 8-bit external
memory or I/O device, only D0-7 should be
used.
D15-14,
D13-12,
D11-10,
D9-8
N/A 149-148
156-155
4-3
28-27
RD 110 150 O O1/2 VCC Read Control. Core external read strobe. Can
be used as output enable for external memory
of I/O devices.
SEL0 N/A 173 O O1/2 VCC Zone Select 0. Chip-select signal for external
memory devices mapped to zone 0.
SEL1 N/A 174 O O1/2 VCC Zone Select 1. Chip-select signal for external
memory devices mapped to zones 1 and 2
(Base Memory). Available in DEV environment
for off-chip emulation of the on-chip flash or
ROM. In IRE and OBD environments, zones 1
and 2 are mapped to the on-chip flash or ROM
and SEL1 output is inactive.
SELIO 112 152 O O1/2 VCC I/O Zone Select. Chip-select signal for external
I/O devices mapped to this zone. Can be used
for mapping off-chip I/O expansion devices to
the core address space.
WR1 N/A 48 O O1/2 VCC Write Control 1 and 0. Indicates writes to bytes
1 and 0, respectively, of the BIU data bus.
WR0 111 151
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 44 Revision1.07
PC87591E/S/L
2.2.5 Development System Support
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
BE1-0 N/A 121,129 O O1/2 VCC Byte Enable bits 1 and 0 on monitor bus
cycles.
BRKL_RSTO N/A 76 I INT/O1/2 VCC Break Line and Reset Out. When the Core
bus is active, the pin is used as a BRKL input.
It Indicates to the core that a breakpoint is
needed once the currently fetched instruction
goes into execution.
When the core bus is not active, the signal is
used as a RSTO output. It indicates to the
system that an internal reset to the core and
its peripherals occurred.
BST2-0 N/A 69,
63-62 OO
1/2 VCC Bus Status bits 2-0 on monitor bus cycles. In
DEV environment, these pins allow monitoring
of the external bus cycles. When OBR bit in
BCFG register is set, the internal bus cycles
are also visible on the external bus. See also
Table 41 on page 273.
CBRD N/A 120 O O1/2 VCC Core Bus Read Status on monitor bus
cycles.
Available in all modes. See Section 4.1.9 on
page 81.
PFS N/A 70 O O1/2 VCC Pipe Flow Status.
PLI N/A 75 O O1/2 VCC Pipe Long Instruction.
TCK 78 106 I INTS VCC JTAG Test Clock.
TDI 80 108 I INTVCC JTAG Test Data In.
TDO 79 107 O O1/2 VCC JTAG Test Data Out.
TINT 77 105 O OD2VCC JTAG Test Interrupt.
TMS 81 109 I INTVCC JTAG Test Mode Select.
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 45 www.national.com
PC87591E/S/L
2.2.6 General-Purpose I/O (GPIO) and Internal Keyboard Scan
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
KBSIN7-0 60-53 80-77,
74-71 IIN
CS/INAC VCC Keyboard Scan Inputs. The input side of the
internal keyboard scan lines. These inputs may
be configured to work with either Schmitt trigger
inputs, for operation with switch based
keyboards, or with internal analog voltage
comparators to interface to a resistive keyboard
matrix. KBSIN7-0 are referenced to VCC and
are designed to work using a 3.3V supply. See
Section 4.14 on page 208 for more details.
KBSOUT15-0 52-37 68-64,
61-56,
53-49
OOD
6VCC Keyboard Scan Outputs. The output side of
the internal keyboard scan lines.
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 46 Revision1.07
PC87591E/S/L
IOPA7-0 33-26 43,
40-36,
33-32
I/O INTS/O3/6 VCC General-Purpose I/O Ports. The GPIO
registers are accessible by the core for read,
write and configuration. Each of these GPIO
signals can be individually configured to be
input or output. The pins may be used as GPIO
or assigned to their respective alternate
functions. See Section 2.4 on page 54 for
assignment of GPIO pins to alternate functions.
See Section 4.5 on page 113 for further details
on the GPIO pins and their functionality.
IOPD1-0 23-22 29, 26
IOPB7-3 123,
6-5,
122-121
165,
6-5,
164-163
I/O INTS/O1/2 VCC
IOPC6-1 2-1,
128-125 176-175
172-169
IOPH3-0 95-92 127-124
IOPI7-0 109-102 147-144
141-138
IOPJ7-2 N/A 76-75
70-71
63-62
IOPJ1-0 111-110 151-150
IOPK7-0 N/A 120-121
129-130
134-135
142-143
IOPL4-0 N/A 48,
103-104
112-113
IOPM7-0 N/A 28-27,
4-3,
156-155
149-148
IOPB2-0 120,
114-113 162,
154-153 I/O INTS/O2/4 VCC
IOPC7 3 1
IOPD7-4 N/A 55-54,
42-41 I/O INTS/O2/12 VCC
IOPD3-2 25-24 31-30
IOPF7-0 89-82 119-114
111-110
IOPH7-4 99-96 133-131
128
IOPC0 124 168 O O3/6 VCC General-Purpose Output Port IOPC0. IOPC0
is are targeted for use as power supply control
for the power supply unit. It is accessible by the
core for write and configuration. On VCC Power-
Up reset, the default state TRI-STATE; it is not
affected by other types of reset. See Section 4.5
on page 113 for further details on these GPIO
pins and their functionality.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 47 www.national.com
PC87591E/S/L
IOPE7-0 21-20,
34,
4,
68-65
25-24,
44,
2,
90-87
IIN
TS VCC General-Purpose Input Port. These pins serve
as input-only pins. The GPIO registers are
accessible by the core for read and
configuration. The pins may be used as GPIO
or assigned to their respective alternate
functions. IOPE0-3 and IOPE5 do not have an
internal pull-up resistor option. Note that
IOPE0-3 and IOPE6-7 are not 5V tolerant. See
Section 2.4 on page 54 for GPIO pin
assignment to alternate functions. See
Section 4.5 on page 113 for further details on
the GPIO pins and their functionality.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 48 Revision1.07
PC87591E/S/L
2.2.7 Host Interface
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
CLKRUN 21 25 I/O INPCI/OD6VDD Clock Run. Same as PCI CLKRUN. When
high, indicates that the LPC clock will be slowed
down or stopped. In this case, the PC87591x
may pull it down to request full speed of the
clock.
GA20 5 5 O O1/2 VCC Gate A20. Implemented using IOPB5 port
output. See Section 5.5.4 on page 322 for
signal operation and behavior when VDD is
down.
KBRST 6 6 O O1/2 VCC Keyboard Reset Output. See Section 5.5.4
on page 322 for signal operation and behavior
when VDD is down.
LAD0-3 10-13 15-13,
10 I/O INPCI/OPCI VDD LPC Address-Data. Multiplexed command,
address bidirectional data and cycle status.
LCLK 16 18 I INPCI VDD LPC Clock. Practically the PCI clock (up to 33
MHz).
ECSCI 25 31 O O2/12 VCC EC SCI. Generates an Embedded Controller
SCI interrupt to the chipset. This signal is
typically connected to one of the chipset GPI
inputs.
LDRQ 8 8 O OPCI VDD LPC DMA Request. Encoded Bus Master
request for LPC I/F.
LFRAME 9 9 I INPCI VDD LPC Frame. Low pulse indicates the beginning
of a new LPC cycle or the termination of a
broken cycle.
LPCPD 20 24 I INPCI VCC Power Down. Indicates that power will be shut
off on the LPC interface.
RESET1 17 19 I INPCI VCC Reset 1. A falling edge on this signal starts a
reset sequence of the PC87591x. For details,
see details in Section 3.2 on page 65.
RESET2 24/123 30/165 I INCS VDD Reset 2. A level low reset to the LPC interface
and Host Controlled Functions configuration
registers and Shared Memory host registers.
For details, see Section 3.2 on page 65.
RESET2 is either assigned to one of two
optional pins or it is disabled, as defined in the
protection words stored in the flash memory.
See Section 2.4.1 on page 54 and
Section 4.16.6 on page 226 for the
configuration of this signal.
PWUREQ 19 23 O O1/2 VCC Power-Up Request.
SERIRQ 7 7 I/O INPCI/OPCI VDD Serial IRQ. The interrupt requests are
serialized over a single pin, where each IRQ
level is delivered during a designated time slot.
SMI 18 22 I/O INTS/OD12 VCC System Management Interrupt.
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 49 www.national.com
PC87591E/S/L
2.2.8 Interrupt and Wake-Up Inputs (ICU and MIWU)
2.2.9 Power and Ground
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
EXWINT20
EXWINT21
EXWINT22
EXWINT23
EXWINT24
EXWINT40
EXWINT45
EXWINT46
22
23
128
2
24
34
20
21
26
29
172
176
30
44
24
25
IIN
TS VCC External Wake-up/Interrupt Inputs. Fed into
the Multi-Input Wake-up Unit (MIWU) for wake-
up or interrupt. Can be used as external
source for wake-up or interrupt. For details on
interrupt and wake-up event assignment, see
Table 17 on page 105.
PFAIL 123 165 I INCS VCC Power Fail. Non-maskable external interrupt
source. This assigned interrupt is non-
maskable only after being enabled by software
after reset.
SWIN 4 2 I INCS VCC Power Switch Input. Indicates a user request
to turn the power on or off. This signal is
connected to the Multi-Input Wake-up Unit
(MIWU) for wake-up of the core domain and
interrupt generation to the core for handling.
For details on interrupt and wake-up event
assignment, see Table 17 on page 105.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
AGND 72 96 I GND Analog Ground. Used as ground for the Analog
to Digital Converter (ADC) and the Digital to
Analog Converter (DAC).
AVCC 71 95 I PWR Analog 3.3V Power supply. Used as power
supply for the Analog to Digital Converter (ADC)
and the Digital to Analog Converter (DAC).
GND 15, 36,
90,
101,
117
17, 35,
46,122,
137,
159,167
I GND Ground. Serves for both on-chip logic, output
drivers and back-up battery circuit. See “Power
Connection and Layout Guidelines” on page 63
for details on connections with AGND.
VBAT 119 161 I INULR Battery Power Supply. Provides battery backup
to the Mobile System Wake-Up Control registers,
to the RTC and to the 32 KHz crystal oscillator
when VCC is lost. The pin is connected to the
internal logic through a series resistor for UL
protection.
VCC 35,
91,100,
115
34, 45,
123,136,
157,166
I PWR Standby Digital 3.3V Power Supply. Used for
all core-domain digital logic and all associated
I/O pins.
VDD 14 16 I PWR Digital 3.3V Power Supply. Serves as power
supply for the LPC interface and some of the
host-controlled functions.
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 50 Revision1.07
PC87591E/S/L
2.2.10 PS/2 Interface
2.2.11 Strap Configuration
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
PSCLK4-1 88, 86,
84, 82 118,
116,
114,
110
I/O INT/O2/12 VCC PS/2 Channel 1 through 4 Clock signal.
PSDAT4-1 89, 87,
85, 83 119,
117,
115,
111
I/O INT/O2/12 VCC PS/2 Channel 1 through 4 Data signal.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
BADDR1-0 95-94 127-126 I INCS VCC I/O Base Address. Sampled at VCC Power-Up
reset to determine the base address of the
configuration Index-Data register pair as follows:
No pull-up resistor: 2E16-2F16
10 Kexternal pull-up
resistor on BADDR0:4E16-4F16
10 Kexternal pull-up
resistor on BADDR1:Core defined
ENV1-0 93-92 125-124 I INCS VCC Environment Select 1 and 0. Sampled at VCC
Power-Up reset to determine the device
operation environment, either IRE, OBD or DEV.
Each pin is pulled to 0 (set environment to IRE =
00) by an internal resistor or set to 1 by an
external 10 Kpull-up resistor.
For further details refer to Section 2.3 on
page 53.
SHBM 97 131 I INCS VCC Shared Host BIOS Memory. Sampled at VCC
Power-Up reset to determine the state of the
shared Host BIOS memory. Pulled to 0 (disables
the shared host BIOS memory) by an internal
resistor or set to 1 by an external 10 Kpull-up
resistor to enable the shared BIOS mode.
TRIS 96 128 I INCS VCC TRI-STATE. Forces the device to float all its
output and I/O pins (except for DAC outputs and
32KX2) if an external pull-up resistor is
connected. Sampled at VCC Power-Up reset.
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 51 www.national.com
PC87591E/S/L
2.2.12 Mobile System Wake-Up Control (MSWC)
2.2.13 Timers and PWM
2.2.14 Universal Synchronous/Asynchronous Receiver/Transmitter (USART)
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
RING 123 165 I INCS VCC Telephone Line Ring. Detection of a pulse
train on this pin is a wake-up event that can
activate the power-up request (PWUREQ). The
pin has a Schmitt Trigger input buffer, powered
by VCC.
RI1 22 26 I INTS VCC Ring Indicator. When low, indicates that a
telephone ring signal has been received by the
modem. Ring signals are monitored during
power-off for wake-up event detection.
RI2 23 29
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
TA2 1 175 I/O INT, O1/2 VCC Timer Pin A for Timers 2 and 1.
TA1 127 171
TB2 2 176 I INTVCC Timer Pin B for Timers 2 and 1.
TB1 128 172
PWM7-0 33-26 43,
40-36,
32-33
OO
3/6 VCC PWM Output 7-0.
Signal 128-Pin
LQFP 176-Pin
LQFP I/O Buffer
Type Power
Well Description
UTXD 114 154 O O2/4 VCC USART Transmit Data.
URXD 113 153 I INTVCC USART Receive Data.
USCLK 120 162 I/O INCS/O2/4 VCC USART Serial Clock. May be used as input or
output when the USART is configured to
operate in its synchronous mode of operation.
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 52 Revision1.07
PC87591E/S/L
2.2.15 Internal Pull-Up and Pull-Down Resistors
The signals listed in Table 5 can optionally support internal pull-up (PU) and/or pull-down (PD) resistors. See Section 7.3 on
page 377 for the values of each resistor type.
Table 5. Internal Pull-Up and Pull-Down Resistors
Signal 128-Pin
LQFP 176-Pin
LQFP Type Comments
ACCESS.bus (ACB)
SCL2-1 125,
121 169,
163 PU80 Programmable
SDA2-1 126,
122 170,
164 PU80 Programmable
General-Purpose I/O (GPIO) Ports
IOPA7-0 33-26 43, 40-36,
33-32 PU80 Programmable
IOPB7-0 123, 6-5,
122,121,120,
114-113
165, 6-5,
164-163,
120,114-113
PU80 Programmable
IOPC7-0 3-1,128-125 3,176-175,
172-169 PU80 Programmable
IOPD7-4 N/A 55-54, 42-
41 PU80 Programmable
IOPD3-0 25-21 31-30, 29,
26
IOPE7,6,4 21-20, 4 25-24, 2 PU80 Programmable
IOPF7-0 89-82 119-114,
111-110 PU80 Programmable
Internal Keyboard Scan (KBC)
KBSIN7-0 60-53 80-77, 74-
71 PU80 Programmable
PS/2 Interface
PSCLK4-1 88, 86,
84, 82 118,116,
114,110 PU80 Programmable
PSDAT4-1 89, 87,
85, 83 119,117,
115,111 PU80 Programmable
Strap Configuration
BADDR1-0 95-94 127-126 PD80 Strap1
1. Active only during VCC Power-Up reset.
ENV1-0 93-92 125-124 PD80 Strap1
TRIS 96 128 PD80 Strap1
SHBM 97 131 PD80 Strap1
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 53 www.national.com
PC87591E/S/L
2.3 STRAP PINS
During VCC Power-Up reset, the ENV(0-1), TRIS, SHBM and BADDR strap input signals are sampled. Internal pull-down
resistors set these signals to 0. These resistors are active only during VCC Power-Up reset. An external 10 Kresistor con-
nected to VCC may be used to set them to 1.
Setting the Environment
ENV0 and ENV1 determine the operating environment. Table 6 shows the settings allowed. Pulling both ENV0 and ENV1
to 1 produces unpredictable results. In IRE and OBD environments, the TRIS strap input may be used for floating all the
device signals. In other cases it should be kept low.
Figures 1 on page 24, 3 on page 31 and 4 on page 32 demonstrate how to use the ENV0-1 signals to configure the
PC87591x for IRE, OBD and DEV environments, respectively.
Other Strap Pin Settings
Table 7 provides brief descriptions of other strap inputs. For details on SHBM and TRIS, see Section 5.3 on page 297 and
Section 4.20.4 on page 272, respectively.
System Load on Strap Pins
The loads on the strap pins should not cause the voltage on them to drop below VIH when the pins should be high (1), or to
rise above VIL when they should be low (0). See Section 7.3.2 on page 377.
If the load caused by the system on the strap pins exceeds 10 µA, use either an external pull-down resistor to keep the pin
at 0 or a pull-up resistor with lower resistance to keep the pin at 1.
To reduce power consumption, in Idle mode, pins with strap inputs on them and a signal function other than GPIO are put
in TRI-STATE or drive the strap-pin value. For pins with strap inputs that function as GPIO, it is recommended that the ap-
plication drive the strap value as output to the value defined by the strap pin. For pins with strap and address line function-
ality, when the address configuration is enabled, the signal is driven by the hardware to its strap value on reset.
Table 6. Environment Pin Settings
Environment ENV0 ENV1 TRIS
IRE 0 0 01
1. When set to 1, the PC87591x is put in TRI-STATE
mode.
OBD 0 1 01
DEV 1 0 0
PROG 1 1 0
Table 7. Other Strap Pin Settings
Strap Pin Internal Pull-Down (0) External Pull-Up (1)
BADDR1-0 SuperI/O Configuration Base Address see Table 47 on page 335
SHBM Disables shared memory with host BIOS Enables shared memory with host BIOS
TRIS Normal operation While in IRE and OBD environments, causes PC87591x to
float its output and I/O signals for system test purposes
and clip-on ISE use
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 54 Revision1.07
PC87591E/S/L
Strap Pin Status Register (STRPST)
The STRPST register is a byte-wide, read-only register. It enables the software to read the value set to strap pins during
Power-Up reset. STRPST bits provide the value of their respective strap input. See Table 7 for bit details.
Location: 00 FF1216
Type: RO
Reset Value: According to external straps
2.4 ALTERNATE FUNCTIONS
2.4.1 GPIO with Alternate Functions
The PC87591x uses the GPIO port pins to multiplex functions, thereby maximizing the device’s flexibility. Table 8 lists all the
pins with such alternate functions and summarizes their selection criteria. To select alternate pin functions, strap inputs flash
memory and configuration registers are used as follows:
The ports’ Alternate Function Control register controls the IOPA, IOPB, IOPC, IOPD, IOPE and IOPF pins. Each of
the ports’ pins may be used as a GPIO port or its alternate function, based on the setting of the corresponding bit in
PxALT register.
The environment setting and MCFG bits control port IOPH, IOPI, IOPJ, IOPK, IOPL and IOPM pins. In IRE and OBD
environments, these pins may function either as GPIO or their alternate function (as indicated in the table). In DEV
environment, they all function as their alternate functions.
Interrupts may be enabled together with the use of the pin as input or with its alternate function when the alternate
function is an input. Enabling the interrupt input is done via the port’s alternate function or the respective bit in EICFG
register.
Strap inputs and their associated internal pull-down resistor function during VCC Power-Up reset.
The Protection Word in the flash configures the use of RESET2 input.
When a pin is used as GPIO and not as its alternate function, disable the alternate function in the relevant module’s register.
Note: In Table 8, the PKG column shows pins available in both 128- and 176-pin packages and pins available only in 176-
pin packages.
Bit 76543210
Name Reserved BADDR1 BADDR0 SHBM
Reset
Table 8. Alternate Function Selection
PKG GPIO Alternate Function 1 Alternate Function 2
128/176 Name Type Module Signal Name Select Module Signal Name Select
128/176 IOPA0 I/O PWM PWM0 PAALT.0
128/176 IOPA1 I/O PWM1 PAALT.1
128/176 IOPA2 I/O PWM2 PAALT.2
128/176 IOPA3 I/O PWM3 PAALT.3
128/176 IOPA4 I/O PWM4 PAALT.4
128/176 IOPA5 I/O PWM5 PAALT.5
128/176 IOPA6 I/O PWM6 PAALT.6
128/176 IOPA7 I/O PWM7 PAALT.7
128/176 IOPB0 I/O USART URXD PBALT.0
128/176 IOPB1 I/O UTXD PBALT.1
128/176 IOPB2 I/O USCLK PBALT.2
128/176 IOPB3 I/O ACCESS.bus SCL1 PBALT.3
128/176 IOPB4 I/O SDA1 PBALT.4
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 55 www.national.com
PC87591E/S/L
128/176 IOPB5 I/O GA20 and
KBRST (GA20) PBALT.5=01
128/176 IOPB6 I/O KBRST PBALT.6
128/176 IOPB7 I/O MSWC RING PBALT.7 ICU PFAIL/
RESET22PBALT.7/
REST2EN=01
128/176 IOPC1 I/O ACCESS.bus SCL2 PCALT.1
128/176 IOPC2 I/O SDA2 PCALT.2
128/176 IOPC3 I/O Timers TA1 PCALT.3
128/176 IOPC4 I/O TB1 PCALT.4 MIWU EXWINT22 PCALT.4
128/176 IOPC5 I/O TA2 PCALT.5
128/176 IOPC6 I/O TB2 PCALT.6 MIWU EXWNT23 PCALT.6
128/176 IOPC7 I/O Clocks CLKOUT PCALT.7 &
MCFG.CLKOM
128/176 IOPD0 I/O MSWC RI1 PDALT.0 MIWU EXWINT20 PDALT.0
128/176 IOPD1 I/O RI2 PDALT.1 EXWINT21 PDALT.1
128/176 IOPD2 I/O RESET2 RST2EN=10 EXWINT24 PDALT.2
128/176 IOPD3 I/O Host I/F ECSCI PDALT.3
128/176 IOPE0 I ADC Voltage AD4 PEALT.0
128/176 IOPE1 I AD5 PEALT.1
128/176 IOPE2 I AD6 PEALT.2
128/176 IOPE3 I AD7 PEALT.3
128/176 IOPE4 I MIWU SWIN PEALT.4
128/176 IOPE5 I MIWU EXWINT40 PEALT.5
128/176 IOPE6 I LPC Interface LPCPD PEALT.6 EXWINT45 EICFG.
EXWINT45
128/176 IOPE7 I CLKRUN PEALT.7 EXWINT46 EICFG.
EXWINT46
128/176 IOPF0 I/O PS2 Interface PSCLK1 PFALT.0
128/176 IOPF1 I/O PSDAT1 PFALT.1
128/176 IOPF2 I/O PSCLK2 PFALT.2
128/176 IOPF3 I/O PSDAT2 PFALT.3
128/176 IOPF4 I/O PSCLK3 PFALT.4
128/176 IOPF5 I/O PSDAT3 PFALT.5
128/176 IOPF6 I/O PSCLK4 PFALT.6
128/176 IOPF7 I/O PSDAT4 PFALT.7
Table 8. Alternate Function Selection (Continued)
PKG GPIO Alternate Function 1 Alternate Function 2
128/176 Name Type Module Signal Name Select Module Signal Name Select
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 56 Revision1.07
PC87591E/S/L
128/176 IOPH0 I/O Core BIU A0 DEV Env or
MCFG.
ENEIO=1
or MCFG.
ENEMEM=1
Straps ENV0 Power-up
128/176 IOPH1 I/O A1 ENV1
128/176 IOPH2 I/O A2 BADDR0
128/176 IOPH3 I/O A3 BADDR1
128/176 IOPH4 I/O A4 TRIS
128/176 IOPH5 I/O A5 SHBM
128/176 IOPH6 I/O A6
128/176 IOPH7 I/O A7
128/176 IOPI0 I/O D0
128/176 IOPI1 I/O D1
128/176 IOPI2 I/O D2
128/176 IOPI3 I/O D3
128/176 IOPI4 I/O D4
128/176 IOPI5 I/O D5
128/176 IOPI6 I/O D6
128/176 IOPI7 I/O D7
128/176 IOPJ0 I/O RD
128/176 IOPJ1 I/O WR0
176 IOPJ2 I/O Development
System
Observability
BST0 DEV Env.
176 IOPJ3 I/O BST1
176 IOPJ4 I/O BST2
176 IOPJ5 I/O PFS
176 IOPJ6 I/O PLI
176 IOPJ7 I/O BRKL_RSTO
Table 8. Alternate Function Selection (Continued)
PKG GPIO Alternate Function 1 Alternate Function 2
128/176 Name Type Module Signal Name Select Module Signal Name Select
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 57 www.national.com
PC87591E/S/L
176 IOPK0 I/O Core BIU A8 DEV Env. or
MCFG.
ENEMEM=1
176 IOPK1 I/O A9
176 IOPK2 I/O A10
176 IOPK3 I/O A11
176 IOPK4 I/O A12
176 IOPK5 I/O A13_BE0
176 IOPK6 I/O A14_BE1
176 IOPK7 I/O A15_CBRD
176 IOPL0 I/O A16
176 IOPL1 I/O A17
176 IOPL2 I/O A18
176 IOPL3 I/O A19
176 IOPL4 I/O WR1 DEV Env. or
(MCFG.
ENEMEM=1
and MCFG.
EXMEM16=1)
176 IOPM0 I/O D8
176 IOPM1 I/O D9
176 IOPM2 I/O D10
176 IOPM3 I/O D11
176 IOPM4 I/O D12
176 IOPM5 I/O D13
176 IOPM6 I/O D14
176 IOPM7 I/O D15
128/176 ADC Voltage AD9 ADCCNF. REM-
DEN=0 ADC Temp DN ADCCNF.
REMDEN=1
128/176 AD8 DP
1. GA20 is implemented using the GPIO.
2. RESET2 use is orthogonal to the other alternate functions and is determined by the setting in the on-chip flash
Protection Word (see Section 4.16.6 on page 226), although it is recommended to use it in conjunction with an
interrupt on the same pin. See “Using RESET2 Input” on page 67.
Table 8. Alternate Function Selection (Continued)
PKG GPIO Alternate Function 1 Alternate Function 2
128/176 Name Type Module Signal Name Select Module Signal Name Select
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 58 Revision1.07
PC87591E/S/L
2.4.2 System Configuration Registers
For a summary of the abbreviations used for Register Type, see Section 2 on page 34.
Register Map
Module Configuration Register (MCFG)
The MCFG register is a read/write, byte-wide register. It is used for global system configuration and setup.
Write operations to the MCFG register should write zeros to all reserved bits. On reset, non-reserved bits of MCFG are
cleared to 0. MCFG can be written in Active mode only. Its contents is preserved in Idle mode.
In IRE and OBD environments, all MCFG fields should be used to designate associated pins as GPIO ports or their alternate
functions. In DEV environment, the pins are always allocated for development system use. The I/O ports functionality can
be implemented using off-chip logic.
To guarantee binary and cycle-by-cycle compatibility among the different environments, define the MCFG fields as required
for IRE and OBD even when in DEV environment, and use the I/O Expansion protocol to build an off-chip implementation
of the I/O ports when they are used by the application.
ADBs or ISE systems use the MCFG Shadow (MCFGSH, write only) register to select the functionality of the signal that
reaches the user’s application.
All write operations to the MCFG must be immediately followed by a write to the MCFG Shadow (MCFGSH) register. This
register is part of the development system and is accessed by an access to the I/O Zone (SELIO).
MCFG is loaded with either 0016 or 8016 on reset. See the description of GTMON for behavior of bit 7 during reset.
Software should load MCFGSH with the MCFG register’s value after reset.
The format of MCFG (and MCFGSH) is as follows:
MCFG Location: 00 FF1016
MCFGSH Location: 00 FBFE16
Type: R/W
Mnemonic Register Name Type
MCFG Module Configuration Register R/W
EICFG External Interrupts Configuration Register R/W
IOEE1 and
IOEE2 Input to Output Echo Enable Register 1 and 2 R/W
Bit 76543210
Name GTMON Reserved CLKOM EXMEM16 ENEMEM ENEIO
Reset See text 0000000
Bit Description
0ENEIO (Enable Expansion I/O). Enables the use of the I/O Expansion protocol for expanding the amount of
GPIO pins available to the application. In IRE and OBD environments, when ENEIO is cleared, the associated
pins are used as GPIO signals. When set, enables the use of BIU I/O Zone (SELIO) for the interface with off-
chip logic. Use the BIU I/O Zone configuration to select the access parameters to the I/O Expansion logic and
its bus width.
1ENEMEM (Enable Expansion Memory). Enables the use of the Expansion memory for expanding the amount
of memory available to the application to more than what is provided on chip. When cleared, the associated pins
are used as GPIO signals. When set, enables the use of BIU Zone 0 (SEL0) and the associated address and
data lines for the interface with flash or SRAM devices. Use BIU Zone 0 configuration to select the access
parameters to the Expansion memory and its width.
Set this bit in the 176-pin package only.
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 59 www.national.com
PC87591E/S/L
External Interrupts Configuration Register (EICFG)
The EICFG register is a read/write, byte-wide register. It enables the use of some of the external interrupts. The EICFG bits
have impact only when the pin is configured to its GPIO function. EICFG is cleared (0016) on reset.
Note that some of the pins that have an external interrupt (not controlled by the EICFG register) have an alternate function
that is an input. When a pin’s alternate function is selected, its interrupt function is also enabled.
The format of EICFG is as follows:
Location: 00 FF0016
Type: R/W
2.4.3 GPIO with Echo Configuration
Some of GPIO pins may be paired to generate an input to output echoing with software masking. The input GPIO are input
ports (Px or Py) with a wake-up function. The output ports are a Px type enhanced with the echo mechanism, as described
in Section 4.5.2 on page 114. The input echoing is enabled only when the respective Echo Enable bit in IOEE1-2 registers
is set. The input port should be configured to enable the interrupt function.
2EXMEM16 (16-bit-Wide Expansion Memory). Enables the use of the 16-bit-wide Expansion memory, when the
ENEMEM is set. The bus width indicated in this register should be the same as the bus width defined in Zone
0 of the BIU (SEL0).
0: The External Memory to be eight bits wide
1: Enables the use of a 16-bit-wide External Memory
4-3 CLKOM (Clock Out Mode). Selects the mode of operation of the CLKOUT signal. This field is in effect only
when this signal is set for output.
Bits
4 3 Description
0 0: Reserved (default)
0 1: CLK - a clock at the core frequency is driven out
1 0: 32.768 KHz clock output
1 1: Reserved
6-4 Reserved.
7GTMON (Go-to Target Monitor Set Flag). This bit is set to indicate that the code should jump to the beginning
of the Target Monitor (TMON). The reset routine of the application should check this bit and behave accordingly.
Once cleared, this bit can not be set by software.
Bit 76543210
Name Reserved EXWINT46 EXWINT45
Reset 00000000
Bit Description
0EXWINT45 (Enable EXWINT45).
0: EXWINT45 input is blocked (disabled) while not being read as a GPIO.
1: EXWINT45 input is open; this enables the detection of changes on the input to trigger interrupts.
1EXWINT46 (Enable EXWINT46).
0: EXWINT46 input is blocked (disabled) while not being read as a GPIO.
1: EXWINT46 input is open; this enables the detection of changes on the input to trigger interrupts.
7-2 Reserved.
Bit Description
2.0 Signal/Pin Description and Configuration (Continued)
www.national.com 60 Revision1.07
PC87591E/S/L
Input to Output Echo Enable Register 1 and 2 (IOEE1 and IOEE2)
The IOEE1 and IOEE2 registers are read/write, byte-wide registers. They enable the echoing of some of the General-Pur-
pose Input ports, equipped with wake-up, to a specified output. The IOEE bits have an impact only when the output GPIO
is configured to its GPIO function. IOEE1 and IOEE2 are cleared (0016) on reset.
The format of IOEE1 is:
IOEE1 Location: 00 FF0216
Type: R/W
Table 9. GPIO Echo Functions Routing and Echo Enable Bit Assignments
Output Port Echo Enable Bit Input Port
IOPA0 EEPA0 bit in IOEE1 register IOPC4/EXWINT22
IOPA1 EEPA1 bit in IOEE1 register IOPE6/LPCPD/EXWINT45
IOPA2 EEPA2 bit in IOEE1 register IOPE7/CLKRUN/EXWINT46
IOPA3 EEPA3 bit in IOEE1 register IOPF6/PSCLK4
IOPA4 EEPA4 bit in IOEE1 register IOPF7/PSDAT4
IOPC0 EEPC0 bit in IOEE2 register IOPE4/SWIN
IOPB0 EEPB0 bit in IOEE2 register IOPD0/EXWINT20
IOPB1 EEPB1 bit in IOEE2 register IOPD1/EXWINT21
IOPB2 EEPB2 bit in IOEE2 register IOPC6/EXWINT23
IOPD3 EEPD3 bit in IOEE2 register IOPD2/EXWINT24
Bit 76543210
Name Reserved EEPA4 EEPA3 EEPA2 EEPA1 EEPA0
Reset 00000000
Bit Description
0EEPA0.
0: Echo Disabled
1: Echo Enabled
1EEPA1.
0: Echo Disabled
1: Echo Enabled
2EEPA2.
0: Echo Disabled
1: Echo Enabled
3EEPA3.
0: Echo Disabled
1: Echo Enabled
4EEPA4.
0: Echo Disabled
1: Echo Enabled
7-5 Reserved.
2.0 Signal/Pin Description and Configuration (Continued)
Revision 1.07 61 www.national.com
PC87591E/S/L
The format of IOEE2 is:
IOEE2 Location: 00 FF0416
Type: R/W
See Table 9 on page 60 for the assignment of the Echo Enable bits to GPIO pairs.
Bit 76543210
Name Reserved EEPC0 EEPD3 EEPB2 EEPB1 EEPB0
Reset 00000000
Bit Description
0EEPB0.
0: Echo Disabled
1: Echo Enabled
1EEPB1.
0: Echo Disabled
1: Echo Enabled
2EEPB2.
0: Echo Disabled
1: Echo Enabled
3EEPD3.
0: Echo Disabled
1: Echo Enabled
4EEPC0.
7-5 Reserved.
www.national.com 62 Revision1.07
PC87591E/S/L
3.0 Power, Reset and Clocks
3.1 POWER
3.1.1 Power Planes
The PC87591x has four power planes (wells), as shown in Table 10.
Table 10. PC87591x Power Planes
For correct PC87591x operation, VCC must be applied whenever VDD is applied. Apply AVCC at the same time that VCC is
applied, protection is provided against rise-time differences only.
3.1.2 Power States
The PC87591x has three main power states:
Battery Fail
Host Domain, Suspend, Analog and Battery Backed power planes are all powered off (i.e., in this case VDD,V
CC,
AVCC and VBAT are all inactive).
Power Fail
Host Domain, Suspend and Analog power planes are powered off. Battery Backed power plane is powered on (i.e.,
in this case VDD,V
CC and AVCC are inactive; VBAT is active).
Power Applied
Suspend, Analog and Battery Backed power planes are powered on, Host Domain power plane may be on or off (i.e.,
in this case VCC,AV
CC are active, VBAT and VDD may be active or inactive).
The Power Applied state has several sub-states, depending on the domain:
The host domain has Host Power On and Host Power Off states, according to the VDD status;
The core domain and host-core interface have Active and Idle states. For details, see Section 4.17 on page 235.
The following power states are illegal:
Host domain on and Suspend and/or Analog off (i.e., VDD active and VCC and/or AVCC are inactive).
Suspend on and Analog off (i.e., VCC active and AVCC inactive) and vice-versa.
Power Plane Description Power Pins Ground Pins
Host Domain Powers the LPC interface and host controlled
functions (except for RTC and MSWC) and
some external signals1
1. See the tables in Section 2.2.1 on page 42 to Section 2.2.13, specifically the Power Well
column, for how the PC87591x external interface signals are assigned to various power
planes.
VDD GND
Suspend Powers the core domain, the host-core interface,
the MSWC and their external signals1VCC GND
Analog Powers some internal analog circuits and their
external signals1AVCC AGND
Battery Backed
Powers the RTC, some MSWC registers, the
32.768 KHz clock/crystal oscillator signals and
some other storage elements that should be
preserved at all times1VPP2
2. VPP is an internal power signal derived from VCC or VBAT. VPP is taken from VCC if it is
greater than the minimum value defined; otherwise, VBAT is used as the VPP source. For
more details on the switching between them, refer to Section 6.2.9 on page 360.
GND
3.0 Power, Reset and Clocks (Continued)
Revision 1.07 63 www.national.com
PC87591E/S/L
The following table summarizes the power states described in relation with the PC87591x power planes.
Figure 10 shows the power state transitions.
Figure 10. Power State Transitions
3.1.3 Power Connection and Layout Guidelines
The PC87591x requires a power supply voltage of 3.3V ±10% for all the digital supplies (VCC and VDD). The analog power
supply requires a voltage of 3.3V ±10% or 3.3V ±5%. A 3.3V ±5% analog supply is recommended since it improves the
accuracy of measuring input voltage values close to the full-scale (see Section 7.4.1 on page 378).
Table 11. PC87591x Power States and Related Power Planes
Power State Host Domain
(VDD)Suspend
(VCC)Analog
(AVCC)
Battery
Backed
(VPP)VBAT
Battery Fail - - - - -
Power Fail - - - + +
Power Applied
Active and Idle x + + + x
Host Power Off - + + + x
Host Power On + + + + x
Illegal1
1. Operation is not guaranteed.
+--xx
x+-xx
x-+xx
VBAT Off and VCC Off (VPP Off)
Battery Fail
Power Fail
Host
Power Off
Host
Power On
Active
Idle
VBAT On (VPP On)
and VCC Off
VCC On and
VCC On
VCC On and
VDD Off
VDD Off VDD On
Hardware
Event
VCC On and
VDD On
VCC On
VDD On
Power Applied
(VCC On)
VBAT On (VPP On)
and VCC Off
Core DomainHost Domain
Active
with WAIT
Software
Controlled
Hardware
Event
Software
Controlled
VDD Off
3.0 Power, Reset and Clocks (Continued)
www.national.com 64 Revision1.07
PC87591E/S/L
Both AVCC and VCC should be applied for correct operation; and although the PC87591x is protected against damage if op-
erated with only one of them (AVCC or VCC), the ADC and DAC modules do not function correctly in such a case and may
cause current leakage. Therefore, ADC and DAC modules should be left at their reset condition (disabled) or disabled by
firmware until AVCC is within the limits specified above. In addition, the AVCC is internally isolated from VCC to enable AVCC
to be externally filtered or driven by a low-noise power supply.
ThePC87591x is designed to operate with a Lithium backup battery that supplies voltage up to 3.6V. The PC87591x includes
an internal current-limiting resistor on the VBAT input as required to meet UL regulations.
VDD,V
CC and VBAT use a common ground return, named digital ground and marked GND. The analog circuits supplied by
AVCC use a separate ground return, named analog ground and marked AGND. This ensures effective isolation of the analog
modules from noise caused by the digital modules.
The following directives are recommended for the PC87591x power and ground connections (see Figure 11 for the power
supply connections):
Ground Connection
Use two ground planes, one for the digital signals (GND) and one for the analog signals (AGND). The following ground con-
nections should also be made:
The analog ground plane (AGND) should be connected at only one point to the digital ground plane (GND). This point
should be located physically near the PC87591x.
The analog ground return pin of the PC87591x (AGND) should be connected to the analog ground plane.
The decoupling capacitors of the analog supply (AVCC) pin should be connected to the analog ground plane as close
as possible to the AGND pin.
The ground reference of the voltage input signals to the ADC module (VIN0-9 in Figure 11) should be connected to
the AGND plane close to the PC87591x.
The ground reference of the voltage output signals from the DAC module (VOUT0-3 in Figure 11) should be connected
to the AGND plane close to the PC87591x.
All GND pins of the PC87591x must be connected to the GND plane.
The decoupling capacitors of the Suspend digital supply (VCC) pin should be located near each VCC-GND pin pair;
one side of each capacitor should be connected to the ground plane.
The ground reference of the voltage input signals to the ACM module (KBVIN0-7 in Figure 11) should be connected
to the GND plane close to the PC87591x.
The decoupling capacitors of the Host digital supply (VDD) pin should be located near the VDD-GND pair; one side of
each capacitor should be connected to the ground plane.
The ground return and the decoupling capacitor of the backup battery supply (VBAT) pin should be located near the
PC87591x; one of the capacitor’s sides should be connected to the ground plane.
Note that low-impedance ground layers improve noise isolation and reduce ground bounce problems.
Power Connection
All PC87591x supply pins must be connected to the appropriate power plane, and decoupling capacitors must be used as
recommended below.
The analog supply pin, AVCC, should be connected to a low-noise power supply that has the same voltage as the digital
supply (3.3V). If the AVCC pin is connected to the same power supply as the VCC pin, it is recommended to use an external
LC or RC filter for the AVCC pin. An example of an LC filter [L1and (C1+C2)] is shown in Figure 11. An RC filter is obtained
by replacing L1 (in Figure 11) with a 10 resistor (not shown in the figure).
Decoupling Capacitors
The following decoupling capacitors should be used to reduce power supply deeps, ground bounce and EMI (refer to
Figure 11 for the position of capacitors, e.g., C1, C2, etc.):
Suspend digital supply (VCC): Place one 0.1 µF capacitor (C3) on each VCC-GND pin pair as close as possible to the
pin pair. Also, place one 1047 µFC
4tantalum capacitor on the common net as close as possible to the chip.
Host digital supply (VDD): Place one 0.1 µF capacitor (C5) on the VDD-GND pin pair as close as possible to the pin
pair. Also, place one 10-47 µF tantalum capacitor (C6) on the common net as close as possible to the chip.
Backup battery (VBAT): Place one 0.1 µF capacitor (C7) on the VBAT pin as close as possible to the pin.
Analog supply (AVCC): Place a 0.1 µF capacitor (C2) and a 10-47 µF tantalum capacitor (C1) on the AVCC pin as
close as possible to the pin.
3.0 Power, Reset and Clocks (Continued)
Revision 1.07 65 www.national.com
PC87591E/S/L
3.2 RESET SOURCES AND TYPES
The PC87591x has several input reset types:
VPP Power-Up reset (for VPP supplied functions only)
Activated when either VCC or VBAT is powered up after both have been off.
VCC Power-Up reset
Activated when VCC is powered up.
Warm reset
Activated on RESET1 input falling edge.
WATCHDOG and Debugger Interface resets:
WATCHDOG reset
Activated on request from the TWD module (WATCHDOG signal is asserted); see Section 4.10 on page 164.
Debugger Interface reset
Activated on request from the Debugger Interface module used during debug and flash updates; see Section 4.19
on page 248.
Host Domain reset
This is divided into two sub-groups: Host Domain Hardware and Host Domain Software reset. Combinations consist-
ing of the flowing events are used to trigger these reset operations:
RESET1 active
When VDD is active, RESET2 is active
On VDD power-up
A Software reset triggered by a write of 1 to bit 1 of SIOCF1 register in the SuperI/O Configuration registers; see
Section 6.1.8 on page 343
Unless otherwise noted, reset references throughout the PC87591x modules default to the following types:
For VPP retained functions: VPP Power-Up reset
For core domain functions and host-core interface functions: VCC Power-Up reset, Warm reset, WATCHDOG reset,
Debugger Interface reset and Software reset
For host domain functions: Host Domain reset
VCC
GND
Digital Ground Plane
Analog
AVCC
C3 0.1
C2
0.1 AGND
Analog Ground Plane
Power
+
C1
AD0
AD9
VIN0
VIN9
C4
22
+
22
VIN
µF
µ
F
µFµF
L1
10-100 µH
(3.3V)
ZL
DA0
DA3
VOUT0
VOUT3
Suspend
Digital
Power
(3.3V)
VDD C5
0.1
C6
22
+
µFµF
BAT
VBAT
(3.3V)
Digital
Power
Host
Backup
Power
C7
0.1
µF
PC87591x
Figure 11. PC87591x Power Supply Connection
KBVIN0
KBVIN7 KBVIN
KBSIN0
KBSIN7
3.0 Power, Reset and Clocks (Continued)
www.national.com 66 Revision1.07
PC87591E/S/L
In DEV environment, the PC87591x outputs to the BRKL_RSTO signal an indication that a reset occurred at the core
domain. See Section 4.20.3 on page 272 for the implementation and usage of RSTO.
The following sections detail the sources and effects of the various resets on the PC87591x, per reset type.
3.2.1 VPP Power-Up Reset
VPP is an internal power signal derived from VCC and VBAT.V
PP Power-Up reset is generated by an internal circuit that de-
tects the status of the VPP power. VPP Power-Up reset signal is active from the rising of VPP until the VPP power is detected
as “good” (i.e., VPP is above VBATDTC). When active, this signal resets all registers whose values are retained by VPP.
For more details, see Section 6.2.9 on page 360.
3.2.2 VCC Power-Up Reset
VCC Power-Up reset is generated by an internal circuit. The PC87591x performs a VCC Power-Up reset when VCC power is
applied. This reset is completed tIRST after the internal clocks have stabilized (see Section 7.6.2 on page 384).
If the 32 KHz crystal is disabled before VCC power-up, external devices should wait at least t32KOSC before accessing the
PC87591x. Any host processor access during this time results in:
The host processor is stalled (by driving a “Long WAIT sync” response on the LPC bus) until after the reset process
is completed and the bus request can be performed.
If HRAPU bit in MSWCTL1 register is set (1), the host processor is reset by asserting KBRST until the internal reset
is completed.
On VCC Power-Up reset, the PC87591x responds as follows:
Enables the 32 KHz crystal, if it is disabled.
Resets the High-Frequency Clock Generator (HFCG) to its default frequency.
Loads default values to all registers whose values are retained by VCC.
Puts pins with strap options into TRI-STATE and enables the internal pull-downs on the strap pins.
Samples the values of the strap pins.
Resets the TAP controller of the Debugger Interface module.
Resets the MSWC, excluding those MSWC registers whose values are retained by VPP
.
Resets Port PC0.
Carries out all the Warm reset actions (see below).
3.2.3 WATCHDOG Reset and Debugger Interface Reset
The PC87591x generates a WATCHDOG reset on request from the TWD module (i.e., a WATCHDOG signal is asserted).
It generates a Debugger Interface reset on request from the Debugger Interface module (reset command). During these re-
sets, the PC87591x performs the VCC Power-Up reset actions, with the following exceptions:
The PC87591x does not sample the value of any strap pin; instead, it maintains the configuration determined by the
strap pins at VCC Power-Up reset.
It does not reset the TAP controller.
On Debugger I/F, reset PC0 is not reset (it is reset on WATCHDOG reset).
It resets the HFCG to its default frequency.
Some MSWC registers do not reset on WATCHDOG or Debugger I/F reset.
The reset periods are identical to the VCC Power-Up reset period.
3.2.4 Warm Reset
Warm reset is activated on the falling edge of RESET1 input. If Warm reset and VCC Power-Up reset occur at the same time,
VCC power-up takes precedence.
3.0 Power, Reset and Clocks (Continued)
Revision 1.07 67 www.national.com
PC87591E/S/L
During a Warm reset, the PC87591x responds as follows:
Terminates core executed instructions
Discards results not yet written to memory
Eliminates any pending core interrupts and traps
Clears the internal latch for the core domain’s edge-sensitive external interrupt
Deactivates the external bus control signals WR(0-1), SEL(0-1), SELIO, RD and BST(0-2)
Puts the address A(0-19) and data D(0-15) buses in TRI-STATE
Switches to core domain’s Active mode
Loads default values into registers, with the exception of:
The Mobile System Wake-Up Control (MSWC) and RTC registers retained by VPP
.
Some registers that are specifically noted to be cleared only by other events
Resets the Debugger interface, except for TAP controller
During Warm reset, strap pins are not sampled and the configuration determined at VCC power-up is unaffected by subse-
quent Warm resets.
The PC87591x core domain and some parts of the host-core interface functions can operate when RESET1 is still asserted
(low). Some parts of the Host Domain Functions that are reset by the Host Domain reset (see following section) are kept
reset as long as RESET1 is asserted.
3.2.5 Host Domain Reset
Using RESET2 Input
The RESET2 input signal is enabled as an alternate function on one of two pins. The Protection Word in the flash memory
is used to define whether the RESET2 input is enabled and, if so, on which of the two pins. See Section 4.16.6 on page 226
for details on RESET2 input configuration.
Note that enabling RESET2 input on either of the signals causes that pin to be used as an input GPIO with an interrupt input
associated with it. It is recommended to use this interrupt function to interrupt the core when a RESET2 event occurs and
to use the interrupt routing to stop activities and resume default values to some system elements not directly reset by the
event.
Host Domain Reset Actions
The reset actions on the host domain are broken into two categories that depend on the reset event source; some of the
actions may happen for both these reset source types and thus are named Host Domain Rest.
Host Domain Hardware Reset: While RESET1 is active, RESET2 is also active if VDD is on or during VDD power-up.
Host Domain Hardware reset performs the following actions:
It brings the LPC interface state machine to its inactive state.
It resets all SuperI/O configuration registers except for those that are battery-backed (see Section 6.1.8 on page 343).
It resets Shared Memory Host Controlled registers
Host Domain Software Reset: This reset is triggered by a write of 1 to bit 1 in SIOCF1 register in the SuperI/O Configura-
tion registers.
Host Domain Software reset performs the following actions:
It resets all SuperI/O configuration registers except those noted to be protected from software reset (i.e., bits that are
locked from write accesses).
It resets Mobile System Wake-Up Control (MSWC) bits and RTC bits marked to be reset by software.
Note that lock bits and memory protect bits are not reset by software reset; instead, they require a hardware reset to unlock
them; this requirement protects these bits from any faulty or malicious software.
For more details, see Section 6.1.3 on page 341.
Host Domain Reset: This term is used when a bit is reset by either a Host Domain Hardware reset or Host Domain Soft-
ware reset.
3.0 Power, Reset and Clocks (Continued)
www.national.com 68 Revision1.07
PC87591E/S/L
3.3 CLOCK DOMAINS
The PC87591x has three clock domains, as shown in Table 12.
Core Domain Clock
The core clock is sourced by the HFCG. The following section gives an overview of the clock domain.
On VCC Power-Up reset, the HFCG is set to generate a 4 MHz clock. The HFCG frequency can be modified by core firm-
ware. See Section 4.18 on page 239.
On WATCHDOG reset (or Debugger interface reset), the HFCG is reset.
LPC Clock
The LPC interface is driven by the LCLK input. LCLK frequency can be up to 33 MHz. The clock CLKRUN signal may be
used as part of a power management scheme that slows the clock down; see “CLKRUN Functionality” on page 343.
RTC (32 KHz) Clock
The RTC clock is the reference for the generation of all other clocks in the PC87591x. The clock is enabled at VCC power-
up and is kept active while VPP is active. Keeping the RTC clock active significantly reduces the PC87591x wake-up time.
The RTC clock is used for time keeping in the RTC; it is also fed into the Power Management Controller (PMC), which pro-
vides the clock to other functions (such as TWD and ACM) that are active at all times (including Idle).
Table 12. PC87591x Clock Domains
Clock Domain Frequency Source Usage
Core See Section 4.18
on page 239 HFCG Core domain and host-core interface
LPC Up to 33 MHz LPC clock input LPC bus interface
RTC 32 KHz Clock input or on-chip oscillator1
1. See Section 6.2.3 on page 356 and Section 6.2.4 on page 357.
RTC, HFCG, TWD, PMC, ACM
Revision 1.07 69 www.national.com
PC87591E/S/L
4.0 Embedded Controller Modules
4.1 BUS INTERFACE UNIT (BIU)
The BIU directly interfaces with a wide variety of devices, including ROM, SRAM and flash memory devices and I/O devices.
It interfaces via address, data and control buses without the need for external glue logic.
The BIU also defines the access time to the on-chip flash Main block to provide cycle-by-cycle compatibility between envi-
ronments; see Section 1.4 on page 29 and “Accessing Base Memory” on page 35. To optimize access time to the on-chip
Base Memory, the Base Memory is split into Fast and Slow Zones. These zones are associated with Zone 1 and Zone 2 of
the BIU, respectively. The SEL1 output signal of the PC87591x is the logical AND of the two SELi outputs of Zones 1 and 2.
4.1.1 Features
Four address zones for static devices (SRAM, ROM, flash, I/O).
Basic bus cycle: two clock cycles.
Configurable fast read bus cycles with 1-cycle read duration.
Wait states: configurable between zero and seven clock cycles.
Hold cycles: configurable between zero and three clock cycles.
I/O expansion support.
Configurable burst on read.
Burst read: one clock cycle.
Configurable early write or late write.
Bus width: configurable per zone - 16-bit or 8-bit.
4.1.2 Functional Description
Interface
The BIU interfaces between:
Internal core bus
External static memory
Off-chip I/O (memory-mapped) devices
The BIU performs the following functions:
Distinguishes between four static memory zones
Selects the relevant configured parameters of the accessed zone (e.g., the number of wait states)
Issues the appropriate bus cycle to access the zone
Each memory zone has a different address range and a set of parameters that define access to this zone. The set of pa-
rameters is software configurable.
Static Memory and I/O Support
The BIU accesses static memory devices (ROM, SRAM, flash and I/O devices) using static read and write bus cycles. The
BIU can be configured to extend the bus cycles with wait cycles.
The BIU supports burst read bus cycles if the accessed zone is configured as burstable. (A burst-read bus cycle is an ex-
tension of the basic-read bus cycle in which additional data is accessed. A burst access usually requires only one clock cycle
per additional data item. It may be extended by up to two clock cycles per additional data item.)
To support both I/O and static memory devices that require long hold times at the end of the access, the BIU can be config-
ured to add up to three Thold clock cycles at the end of the bus cycle. In addition, the BIU can be configured to insert a Tidle
clock cycle between two consecutive accesses to different zones.
Byte Access
The internal core bus is 16-bits wide and supports byte and word transactions.
The BIU issues the appropriate bus cycle to access the right bytes, according to the core bus transaction and the memory de-
vice bus width. Table 13 and Table 14 summarize the details:
4.0 Embedded Controller Modules (Continued)
www.national.com 70 Revision1.07
PC87591E/S/L
Table 13. Bus Cycles of a 16-Bit Data Bus
Table 14. Bus Cycles of an 8-Bit Data Bus
On write cycles of a single byte, the remaining eight bits of the bus are floating.
On read cycles of a single byte, the remaining eight bits of the bus are ignored. There is no need for external pull-up resistors.
Clock and Bus Cycles
There are two types of bus cycles: data transfer and non-data transfer. Data transfer bus cycles cause transfer of data from
or to the memory device. Non-data transfer bus cycles (described in Section 4.1.9 on page 81) are used for observability of
internal bus transactions and do not involve data transfer from or to external devices.
There are four types of data transfer bus cycles:
Early write
Late write
Normal read
Fast read
The BIU uses EWR configuration bit in BCFG register to select the early or late write data transfer bus cycle. It uses FRE in
SZCFGn register (where “n” refers to zone 0, 1 or 2) to select normal read or fast read data transfer bus cycles.
The basic late write bus cycle takes two clock cycles. The basic early write bus cycle takes three clock cycles. When the BIU
uses the early write bus cycle, the RD signal is not required for interfacing with the memory device (with the exception of
flash). On reset, the early write bus cycle is configured.
The basic normal read bus cycle takes two clock cycles. Fast read bus cycle always takes one clock cycle. On reset, the
normal read bus cycle is configured.
Notes:
1. In the descriptions that follow, the “n” in SELn signal refers to two of the three available BIU select signals (numbered 0
or 1, corresponding to zone 0 or zone 1 respectively). The third signal is labelled SELIO.
2. For all timing diagrams, the value of BST0-2 depends on the type of core bus transaction.
3. In the following paragraphs, SZCFGn refers to three of the four BIU zone configuration registers (n = 0, 1 or 2) - the fourth
configuration register is labelled IOCFG.
Number of
Bytes Transferred Core
Bus Bytes Address (LSB) Data Bus Pins
1 B0 0 0-7
1 B1 1 8-15
2 B1 B0 0 0-15
2 B1 1 8-15
B0 Then 0 0-7
Number of
Bytes Transferred Core
Bus Bytes Address (LSB) Data Bus Pins
1 B0 0 0-7
1 B1 1 0-7
2 B0 0 0-7
B1 Then 1 0-71
1. Burst bus cycle, if burstable; otherwise, the core transaction is
broken into “basic” bus cycles.
2 B1 1 0-7
B0 Then 0 0-7
4.0 Embedded Controller Modules (Continued)
Revision 1.07 71 www.national.com
PC87591E/S/L
4.1.3 Clock Cycles
Basic Bus Cycle
A basic bus cycle comprises one to three clock cycles (depending on the type of bus cycle). Adding extra wait or hold clock
cycles extends the data transfer bus cycles. Every data transfer bus cycle has the T1 and T2 clock cycles, with the exception
of the fast read bus cycle, which has only one clock cycle (T1-2).
Tidle Cycle Clock cycles that are not used for bus cycles are called Idle clock cycles (Tidle). Tidle cycles are added when the
BIU does not need to generate a bus transaction or as specifically configured pauses between two consecutive transactions.
When more than one Tidle cycle is requested as a pause, the Tidle cycles overlap and only one Tidle cycle is added.
Tidle clock cycles can be inserted between two consecutive accesses in different zones (to allow long hold times or buffer
disable times). To do this, either program IPRE and/or IPST in SZCFGn register (or IPST in IOCFG register); see Figure 18
on page 77.
Tidle clock cycles are also added between an early write and a read bus cycle, and between a late write and a fast read bus
cycle; see Figure 23 on page 80.
T1 Cycle Every bus cycle starts with T1. In this clock cycle, the address of the selected device (either external or internal)
is set on the address pins. Write bus cycles never drive data during T1.
T2 Cycle The read T2 bus cycles always sample the data at the end of T2.
The write T2 bus cycles always drive data during T2. If no Thold clock cycles follow, the data bus is put in TRI-STATE after
the T2 cycle.
T1-2 Cycle The fast read T1-2 bus cycle is a one-cycle read transaction.
At the start of the clock cycle, the address of the selected device is set on the address pins, and the SELn and RD signals
are activated. At the end of the clock cycle, the BIU samples the data.
T3 Cycle Early write bus cycles always have the T3 clock cycle. No other bus cycles have this clock cycle.
At the start of this clock cycle, SELn (or SELIO) is deactivated; then WR0-1 is deactivated. The address and data remains
valid until T3 is completed. If no Thold clock cycles follow, the data bus is put in TRI-STATE after the T3 cycle.
Optional Clock Cycles
The following clock cycles are optional in a data transfer bus cycle:
TIW (Internal Wait)
T2B (T2 burst)
TBW (Burst Wait)
Thold
TIW Cycle Extend the basic data transfer bus cycle by adding wait clock cycles. To do this, program WAIT in SZCFGn reg-
ister (or IOCFG register) with the required additional wait clock cycles. Wait clock cycles generated by this action are named
TIW (internal wait). TIW cycles are added after T1 and followed by T2 cycles. Data is always driven during wait clock cycles
of a write bus cycle.
T2B Cycle Data of read burst bus cycles is sampled at the end of T2B. If the TBW cycle is not configured, the address is
changed at the start of T2B. Write bus cycles do not have this clock cycle.
TBW Cycle A burst bus cycle can be extended by one wait clock cycle, named TBW. This is done according to WBR in
SZCFGn register. The address is changed at the start of TBW. Write bus cycles do not have this clock cycle.
Thold Cycle Hold cycles are added after T2 or T2B (if there is a burst bus cycle) or T3 (according to HOLD in SZCFGn or
IOCFG register); the address and data (during a write bus cycle) are always valid during these cycles. The data bus is put
in TRI-STATE after the last Thold.
Other Clock Cycles
Special Tidle Cycle During Tidle cycles, one of the SEL0-1 signals and the RD signal may be activated for one clock cycle.
This happens due to special activity on the internal core bus. To avoid contention on the memory bus, it is guaranteed that
this clock cycle is followed by a sufficient number of Tidle cycles before the next T1 cycle is performed.
The number of Tidle cycles that follows is at least the number required by the selected zone as configured in HOLD field in
SZCFGn register.
4.0 Embedded Controller Modules (Continued)
www.national.com 72 Revision1.07
PC87591E/S/L
Burst Read Cycles A read bus cycle consisting of the basic bus cycle plus additional clock cycles called “burst bus cycles”.
The burst bus cycles occur if the bus is burstable (BRE in SZCFGn register is 1), the configured bus width is eight bits and
the core attempts to read a word. When the bus is not burstable (BRE in SZCFGn register is 0), the BIU issues two separate
read bus cycles. Write bus cycles are never burstable, and the BIU always issues two separate write bus cycles.
Control Signals
The write bus cycles use byte write qualifiers on WR0-1 pins:
They access an 8-bit wide memory on D0-7 data lines.
One byte is accessed on basic bus cycles. Only the WR0 pin is used as the byte write qualifier.
They access a 16-bit wide memory on D0-15 data lines.
Either one or two bytes are accessed on basic bus cycles. The WR0 pin is used as an even byte (D0-7) write qualifier
and WR1 pin is used as an odd byte (D8-15) write qualifier.
4.1.4 Early Write Bus Cycle
If EWR in BCFG register is 1, the BIU uses early write bus cycles. This allows removal of the RD signal from the memory
device interface. The basic early write bus cycle takes three clock cycles.
The cycle starts at T1; at this point, the data bus is in TRI-STATE, the address is placed on the address bus and RD is in-
active. indicating that this is a write bus cycle. Then, WR0-1 are activated.
At the first TIW or T2 (when there are no TIW cycles), the data is placed on the data bus and the SELn (or SELIO) is acti-
vated. The bus transaction is terminated at T3; at this point, SELn (or SELIO) becomes inactive. Then WR0-1 become in-
active and the data bus is put in TRI-STATE. The address remains valid until T3 is complete.
Thold clock cycles may follow T3, according to HOLD in SZCFGn or IOCFG registers (may be 0). The address and data re-
main valid until the end of the last Thold cycle. The data is put in TRI-STATE in the clock cycle after the last Thold or T3 (if no
Thold cycle is configured); see Figures 12, 13 and 14.
If a read bus cycle immediately follows an Early Write bus cycle, an idle cycle is added between the two.
4.0 Embedded Controller Modules (Continued)
Revision 1.07 73 www.national.com
PC87591E/S/L
HOLD field in SZCFGn reg. 0
WAIT field in SZCFGn reg. 0
T2
SELn: inactive, WR0-1: inactive;
if HOLD field in SZCFGn reg. = 0 data put in TRI-STATE.
WAIT field in SZCFGn reg. = 0
Hold cycles completed
Address placed on A0-19,
WR0-1: activated
Data placed
on D0-15,
SELn: active Internal waits completed
HOLD in SZCFGn reg. = 0
Address on A0-19 invalid/changed
Data put in TRI-STATE
Data placed on D0-15,
SELn: active
Internal waits corresponding to Wait field in SZCFGn register.
T1
T2
Thold Hold cycles according to HOLD field
in SZCFGn reg.
TIW
T3
T1
end
begin
Note: References to SZCFGn also apply to the IOCFG register.
References to SELn also apply to the SELIO signal.
Figure 12. Early Write Bus Cycle
4.0 Embedded Controller Modules (Continued)
www.national.com 74 Revision1.07
PC87591E/S/L
4.1.5 Late Write Bus Cycle
If EWR in BCFG register is 0, the BIU uses the late write bus cycle. The basic late write bus cycle takes two clock cycles.
This write bus cycle requires the RD signal in the memory device interface.
A write bus cycle starts at T1. When the data bus is in TRI-STATE, the address is placed on the address bus and SELn (or
SELIO) is activated. Next, WR0-1 are activated. RD is inactive to indicate this is a write transaction.
CLK
A0-19
SELx
SELy
RD
WR0-1
D0-15
Normal Read Early Write Read,
T1 T2 T1 T2 T1 T2
All Other Zones
T3
In In
BST0-2 (Note)
(x y)
(y x)
Out
Figure 13. Early Write Following Normal Read with 0 Wait
Bus State
CLK
A0-19
SELn
RD
WR0-1
D0-15
T1 TIW T2 T3 THold
Out
BST0-2
Figure 14. Early Write Bus Cycle with 1 Internal Wait and 1 Hold
Bus State
4.0 Embedded Controller Modules (Continued)
Revision 1.07 75 www.national.com
PC87591E/S/L
At the first TIW or T2 (when there are no TIW cycles), the data is placed on the data bus. The bus cycle is completed at T2;
at this point, WR0-1 are deactivated. The address and data remain valid until T2 is completed.
After T2, the number of Thold cycles specified by HOLD in SZCFGn register (may be 0) is added to the transaction. When
Thold cycles are added, the address and data remain valid until the end of the last Thold cycle. SELn (or SELIO) is deactivated
on the first Thold cycle. When no Thold cycles are specified, SELn (or SELIO) is deactivated in the clock cycle after T2 unless
another read or write from the same zone follows. The data is put in TRI-STATE in the clock cycle after the last Thold or T2
(if no Thold cycle is configured); see Figures 15, 16 and 17.
Hold cycles
according to
HOLD in
SZCFGn reg.
HOLD field in SZCFGn reg. 0
WAIT field in SZCFGn reg. 0 WAIT field in SZCFGn reg. = 0
First Thold;
SELn: inactive.
Hold cycles completed
Address placed on A0-19;
SELn: activated;
WR0-1: activated.
Data placed
on D0-15
Internal waits completed
HOLD field in SZCFGn reg. = 0
Address on A0-19 invalid/changed;
Data put in TRI-STATE;
SELn: inactive.
Data placed on D0-15;
WR0-1: inactive.
Internal waits corresponding to WAIT field in SZCFGn register
T2
Thold
T1
end
begin
Note: References to SZCFGn also apply to the IOCFG register.
References to SELn also apply to the SELIO signal.
TIW
Figure 15. Late Write Bus Cycle
4.0 Embedded Controller Modules (Continued)
www.national.com 76 Revision1.07
PC87591E/S/L
4.1.6 Normal Read Bus Cycle
A read bus cycle starts at T1; at this point, the address is placed on the address bus, SELn (or SELIO) is activated and
WR0-1 are inactive, indicating that this is a read bus cycle. The RD signal is activated on the first TIW or T2 (when there are
no TIW cycles).
At the end of T2, the BIU samples the data on D0-7 or D0-15, according to BW signal in SZCFGn register. After T2, the
number of Thold cycles specified by HOLD in SZCFGn register (may be 0) is added. SELn and RD are deactivated on the
first Thold cycle. The address remains valid until the end of the last Thold cycle.
CLK
A0-19
SEL0-1,
D0-15
RD
WR0-1
Normal Read Late Write Normal Read
T1 T2 T1 T2 T1 T2
Bus State
In Out In
BST0-2
SELIO
Figure 16. Late Write Bus Cycle Between Normal Read Bus Cycles with 0 Wait
CLK
A0-19
SELn
D0-15
RD
WR0-1
Bus State T1 TIW T2 Thold
BST0-2
Figure 17. Late Write Bus Cycle with 1 Internal Wait and 1 Hold
Out
4.0 Embedded Controller Modules (Continued)
Revision 1.07 77 www.national.com
PC87591E/S/L
When no Thold cycles are specified, SELn is deactivated in the clock cycle that follows T2, unless another read from the
same zone follows. The RD signal is always deactivated in the clock cycle following T2; see Figures 18, 19 and 20.
A burst bus cycle supplements the basic read bus cycle if the core attempts to access more bytes (i.e., a word) than the
configured bus width (and BRE in SZCFGn register is set to 1). The burst bus cycle (T2B) follows T2 before the Thold cycles
(if configured). A wait clock cycle (TBW) is added between T2 and T2B if WBR in SZCFGn register is set to 1.
The address of the burst bus cycle is changed on TBW (if configured) or T2B (if no TBW). At the end of T2B, data is sampled.
The RD signal is activated during the burst bus cycle and is deactivated in the clock cycle following T2B; see Figures 21 and
22.
CLK
A0-19
SELx
SELy
RD
WR0-1
D0-15
Normal Read
Normal Read
T1 T2 TIdle T1 T2
In In
(x y)
(y x)
BST0-2
Figure 18. Two Basic Normal Read Bus Cycles with Idle In Between (IPST Bit in SZCFGy Register = 1,
IPRE Bit in SZCFGx Register = 1)
Bus State
CLK
A0-19
SELn
D0-15
RD
WR0-1
Bus State T1 TIW TIW T2 THold
BST0-2
Figure 19. Normal Read Bus Cycle with 2 Internal Waits and 1 Hold
In
4.0 Embedded Controller Modules (Continued)
www.national.com 78 Revision1.07
PC87591E/S/L
Other SZCFGn
configuration
HOLD field in SZCFGn reg. = 0
HOLD field in SZCFGn reg. 0
WAIT field in SZCFGn reg. 0 WAIT field in SZCFGn reg. = 0
Address placed on A0-19;
SELn: activated.
RD: active
Address on A0-19 invalid/changed;
SELn and RD: inactive.
RD: active;
End of T2: Data is sampled.
Internal waits corresponding to WAIT field in SZCFGn register.
TIW
TBW
T1
begin
Hold cycles completed
Thold
T2
T2B
end
{BW = 1 or BRE = 0
or core attempts to read a byte}
BW = 0; {WBR,BRE} = 11;
Core attempts to read a word
Next address on A0-19;
End of T2B: Data sampled.
Hold cycles according
to HOLD field in SZCFGn reg.
First Thold: SELn
and RD are deactivated
In SZCFGn reg.: {BW,WBR,BRE} = 001
Core attempts to read a word
Figure 20. Normal Read Bus Cycle
Note: References to SZCFGn also apply to the IOCFG register.
References to SELn also apply to the SELIO signal.
TBW and T2B states do not exist in bus cycles of the IO zone.
Internal waits completed
In SZCFGn reg.: HOLD 0
Next address
on A0-19
In SZCFGn reg.:
4.0 Embedded Controller Modules (Continued)
Revision 1.07 79 www.national.com
PC87591E/S/L
4.1.7 Fast Read Bus Cycle
When FRE bit in SZCFGn register is 1, the fast read bus cycle is enabled for zone n. The fast read bus cycle takes one clock
cycle.
At the start of the T1-2 clock cycle, the address is placed on the address bus, and SELn and RD are activated. WR0-1 are
inactive, indicating a read bus cycle. At the end of the clock cycle, the BIU samples the data. SELn and RD are deactivated
in the following clock cycle, unless another read from the same zone follows. If a write to the same zone follows and late
write is configured, SELn remains activated. The address remains valid until the start of the clock cycle after the T1-2 clock
cycle.
CLK
A0-19
SELn
D0-7
RD
WR0-1
Bus State T1 T2 T2B
In In
BST0-2
Figure 21. Normal Read Bus Cycle with 0 Wait on Burst
CLK
A0-19
RD
WR0-1
D0-7
T1 TIW TIW T2 TBW
In
SELn
T2B
In
BST0-2
Figure 22. Normal Read Bus Cycle with 2 Internal Waits and 1 Wait on Burst
Bus State
4.0 Embedded Controller Modules (Continued)
www.national.com 80 Revision1.07
PC87591E/S/L
The fast read bus cycle cannot be extended by adding wait cycles (WAIT field in SZCFGn register is ignored during this bus
cycle). Additionally, hold cycles cannot be added (HOLD field in SZCFGn register is also ignored). When a write bus cycle
immediately precedes, in sequence, a fast read bus cycle, an idle clock cycle is forced between the two; see Figure 23.
Note that when the core attempts to access more bytes than the configured bus width (i.e., a word), the transaction is broken
up into “basic” (T1-2) bus cycles.
4.1.8 I/O Expansion Bus Cycles
The I/O expansion bus cycles support the implementation of on-chip I/O port functionality (when the pins of the on-chip I/O
ports are used to support DEV environments) and/or additional ports, using off-chip external logic.
I/O expansion bus cycles access the off-chip I/O device using the following signals:
SELIO.
Address lines A0-7.
The RD and WR0-1 signals may be used.
The design minimizes the off-chip logic required to implement the I/O ports. It is costly to implement a port with pins individ-
ually configured for input or output. Implementing ports for input only or output only reduces expenses.
I/O expansion bus cycle is not generated during an access to a port register if one of the following conditions occurs:
A port pin is available on-chip.
All port pins are inputs and the port is being written.
CLK
A0-19
SELx
SELy
RD
WR0-1
D0-15
Fast Late Write Fast
TIdle T1-2 T1 T2 T1-2 T1
Read Read
TIdle
In Out In
BST0-2
(x y)
(y x)
Idle
Cycle
Figure 23. Fast Read Bus Cycle
Bus State
4.0 Embedded Controller Modules (Continued)
Revision 1.07 81 www.national.com
PC87591E/S/L
I/O Expansion Read/Write Bus Cycle
These cycles are always preceded by a Tidle clock cycle (see Figure 24). The I/O zone is not burstable.
I/O Expansion Example
Figure 25 shows an example of how two ports can be implemented off-chip, using I/O expansion. This example implements
two 8-bit ports by connecting the SELIO, RD and WR0 pins to the latch/buffer controls.
4.1.9 Development Support
The BIU provides the following support for development systems.
Bus Status Signals
The Bus Status BST0-2 signals indicate whether a transaction on the core bus was issued; they also indicate the transaction
type; see Table 41 on page 273.
CLK
A0-19
SELIO
RD
WR0-1
D0-15
Read Write
TIdle T1 T2 TIdle T2 T3T1
In Out
BST0-2
Figure 24. I/O Expansion Bus Cycles (EWR bit in BCFG Register = 1)
Bus State
SELIO174x377
74x541
OE1
CE
OE2
WR01
RD
CP 8-Bit
D
8-Bit
Buffer
Figure 25. Example of an Implementation of Two Ports Using I/O Expansion
8
8
8
D0-7 Latch
PC87591x
1. This routing is for late write. If early write, SELIO is routed
to CP and WR0 to CE. All other routing is unchanged.
4.0 Embedded Controller Modules (Continued)
www.national.com 82 Revision1.07
PC87591E/S/L
Core Bus Monitoring
The core bus monitoring cycle is a non-data transfer bus cycle. It takes a single clock cycle - T1. On this cycle:
The address pins display the address of the internal device accessed on the core bus.
CBRD indicates the direction of the access (read or write).
BE0-1 indicate which data bus bytes are accessed (lower or upper).
BST0-2 display the core bus status.
The core bus monitoring cycle, as shown in Figure 26, is generated only when bit 1 (OBR) in BCFG register is 1.
CLK
A0-12,
T1
SEL0-1
WR0-1
D0-15
RD
BST0-2
SELIO
A16-19
CBRD
BE0-1
Figure 26. Core Bus Monitoring Bus Cycle
Bus State
4.0 Embedded Controller Modules (Continued)
Revision 1.07 83 www.national.com
PC87591E/S/L
4.1.10 BIU Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
BIU Register Map
BIU Configuration Register (BCFG)
The BCFG register controls the configuration of common features to all zones. On reset, this register is initialized to 0716.
Location: Index 00 F98016
Type: R/W
Mnemonic Register Name Type
BCFG BIU Configuration R/W
IOCFG I/O Zone Configuration R/W
SZCFGn Static Zone Configuration R/W
Bit 76543210
Name Reserved ISTL OBR EWR
Reset 00000111
Bit Description
0EWR (Early Write).
0: Late write
1: Early write
1OBR (Observability). Determines if the address and status of internal accesses are observable.
0: Not observable (no toggle of external buses)
1: Observable (external buses toggle)
2ISTL (Internal Stall). Determines if the internal bus is stalled while the BIU is busy.
0: Internal bus activity not stalled when BIU is busy
1: Stall internal bus activity when the external bus is busy
7-3 Reserved.
4.0 Embedded Controller Modules (Continued)
www.national.com 84 Revision1.07
PC87591E/S/L
I/O Zone Configuration Register (IOCFG)
The IOCFG register controls the configuration of the I/O zone. On reset, it is initialized to 069F16.
Location: 00 F98216
Type: R/W
Bit 1514131211109876543210
Name Reserved IPST Res BW Reserved HOLD WAIT
Reset 0000011010011111
Bit Description
2-0 WAIT. Number of TIW clock cycles that extend the bus cycle.
Bits
2 1 0 Number
0 0 0: None
0 0 1: One
0 1 0: Two
0 1 1: Three
1 0 0: Four
1 0 1: Five
1 1 0: Six
1 1 1: Seven
4-3 HOLD. Number of Thold clock cycles.
Bits
4 3 Number
0 0: None
0 1: One
1 0: Two
1 1: Three
6-5 Reserved.
7Bus Width. Sets the external bus width used for the I/O zone. It is initialized during reset to its default value.
0: 8-bit bus
1: 16-bit bus (default)
8Reserved.
9IPST (Idle After Bus Cycle). Determines if an idle cycle follows the current bus cycle when the next bus cycle
is in a different zone.
0: No idle cycle inserted
1: Idle cycle inserted
15-10 Reserved.
4.0 Embedded Controller Modules (Continued)
Revision 1.07 85 www.national.com
PC87591E/S/L
Static Zone Configuration Register (SZCFGn)
The SZCFGn register (where n = 0, 1 or 2) controls the configuration of zone n. On reset, SZCFGn is initialized to 069F16.
Location: Zone 0 - 00 F98416
Zone 1 - 00 F98616
Zone 2 - 00 F98816
Type: R/W
Bit 1514131211109876543210
Name Reserved FRE IPRE IPST Res BW WBR BRE HOLD WAIT
Reset 0000011010011111
Bit Description
2-0 WAIT. Number of TIW clock cycles that extend the bus cycle. Ignored when bit 11 (FRE) of this register is set
to 1.
Bits
2 1 0 Number
0 0 0: None
0 0 1: One
0 1 0: Two
0 1 1: Three
1 0 0: Four
1 0 1: Five
1 1 0: Six
1 1 1: Seven
4-3 HOLD. Number of Thold clock cycles.
Bits
4 3 Number
0 0: None
0 1: One
1 0: Two
1 1: Three
5BRE (Burst Read Enable). Ignored when bit 11 (FRE) of this register is set to 1.
0: Disabled
1: Enabled
6WBR (Wait on Burst Read). Determines if a wait state (TBW) is added on a burst read transaction.
0: No TBW
1: TBW
7BW (Bus Width). Sets the external bus width used for the I/O zone. It is initialized during reset to its default
value.
0: 8-bit bus
1: 16-bit bus (default)
8Reserved.
9IPST (Idle After Bus Cycle). Determines if an idle cycle follows the current bus cycle when the next bus cycle
is in a different zone.
0: No idle cycle inserted
1: Idle cycle inserted
4.0 Embedded Controller Modules (Continued)
www.national.com 86 Revision1.07
PC87591E/S/L
4.1.11 Usage Hints
The following usage hints help configure the BIU to maximize PC87591x performance and avoid contention on the data bus.
1. In IRE environment, access time to the internal flash can use zero wait and zero hold cycles or fast reads depending on
the CLK frequency set for the core and its peripherals (see “Flash Read, Write and Erase Time” on page 222).
Flash sections 0 and 1 (fast zone) and Section 2 (slow zone) can use a fast read bus cycle through the operation fre-
quency of the PC87591x; therefore, program SZCFG1 fields to be: WAIT=000, HOLD=00, BRE=0, WBE=0, BW=1,
FRE=1.
When Section 2 (slow zone) can operate with a fast read bus cycle, program SZCFG2 fields to be: WAIT=000,
HOLD=00, BRE=0, WBE=0, BW=1, FRE=1.
When Section 2 (slow zone) needs to operate with normal read and zero wait, program SZCFG2 fields to be: WAIT =000,
HOLD=00, BRE=0, WBE=0, BW=1, FRE=0.
2. To avoid contention on the data bus when a read bus cycle (no Thold clock cycles) in one zone is followed by a read bus
cycle in another zone, program IPST and IPRE in the different memory (I/O) zones as follows:
10 IPRE (Idle Before Bus Cycle). Inserts an idle cycle before the current bus cycle when this bus cycle is in a new
zone.
0: No idle cycle inserted
1: Idle cycle inserted
11 FRE (Fast Read Enable).
0: Disabled - Normal read bus cycle takes at least two clock cycles
1: Enabled - Normal read bus cycle takes one clock cycle
15-12 Reserved.
Zone IPRE IPST
Zone 0 0 0
Zone 1 1 0
Zone 2 0/11
1. Set IPRE when the zone is con-
figured for fast read.
0
Zone I/O 12
2. An IPRE is forced always for
Zone I/O.
0
Bit Description
Embedded Controller Modules (Continued)
Revision 1.07 87 www.national.com
PC87591E/S/L
4.2 DMA CONTROLLER (DMAC)
The DMAC transfers blocks of data between memory and I/O devices along four independent channels, with minimal inter-
vention by the core. The source and destination addresses and the block size to be transferred may be defined for each of
the channels.
4.2.1 Features
Four Independent Direct Memory Access (DMA) channels.
Direct (fly-by) and indirect (memory-to-memory) transfer types.
Single-buffer, double-buffer and auto initialize operation modes.
Fixed address (I/O device) or updated (memory device).
Address update (increment or decrement) independent of the number of transferred bytes.
Interrupt line for each channel.
Programmable bus policy for each channel: continuous or intermittent use of the bus.
Software DMA request for each channel.
Maximum throughput in direct (fly-by) transfer:
Intermittent:Every three clock cycles.
Continuous:On internal core bus - every clock cycle.
Otherwise:Every two clock cycles.
Maximum throughput in indirect (memory-to-memory) transfer:
Intermittent:Every five clock cycles.
Continuous:On internal core bus - every two clock cycles.
Otherwise:Every four clock cycles.
4.2.2 Functional Description
When transferring blocks of data using the DMAC, the source and destination addresses, as well as the block size and type
of operation, are set up in advance by programing the appropriate control registers. Actual data transfers are handled by the
DMAC channel in response to DMA transfer requests. On receiving a DMA transfer request (DMRQn), if the channel is en-
abled, the DMAC performs the following operations:
1. Acquires control of the core bus according to the DMAC priority on the core bus.
2. Determines priority among the DMAC channels, one clock cycle before T1 of the DMAC transfer cycle. (T1 is the first
clock cycle of the bus cycle.) Priority among the DMAC channels is fixed in descending order, with Channel 0 receiving
the highest priority.
3. Executes data transfer bus cycle(s) according to the values stored in the control registers of the channel being serviced
and according to the accessed memory address. It acknowledges the request during the bus cycle that accesses the
requesting device.
4. If the transfer of a block is terminated, the DMAC does the following:
Updates the termination flags.
Generates an interrupt if enabled.
Goes to step 6.
5. If DMRQn is still active and the Bus Policy is “continuous”, returns to step 3.
6. Relinquishes the internal core bus.
Each DMAC channel can be programed for direct (fly-by) or indirect (memory-to-memory) data transfer. Once a DMAC
transfer cycle is in process, the next transfer request is sampled when the DMAC acknowledge is deactivated and subse-
quently, on the rising edge of each clock cycle.
The configuration of either address freeze or address update (increment or decrement) is independent of the number of
transferred bytes, transfer direction or number of bytes in each DMAC transfer cycle. All these can be configured for each
channel by programing the appropriate control registers.
Each DMAC channel has eight control registers. DMAC channels are described hereafter with the suffix “n”, where n repre-
sents the channel number in the register name (n = 0 to 3).
4.2.3 Channel Assignment in PC87591x
Table 15 shows the assignment of the DMA channels to different tasks in the PC87591x. If a channel is used for memory
block transfers, other resources must be disabled.
Embedded Controller Modules (Continued)
www.national.com 88 Revision1.07
PC87591E/S/L
Table 15. DMA Channel Assignment
4.2.4 Transfer Types
The DMAC uses two data transfer modes, direct (fly-by)and indirect (memory-to-memory).The choice of mode depends on
the correlation between the source and destination bus lengths, the required bus performance and the peripheral structure
(as indicated in Table 15).
Direct (Fly-By) Transfers
Figure 27. DMAC Direct Bus Cycle Followed by a Core Bus Cycle
In Direct mode, each data item is transferred using a single bus cycle without reading the data into the DMAC. It provides
the fastest transfer rate, but it requires identical source and destination bus widths.
Data transfer cannot occur between two memory elements. One of the elements must be the I/O device that requested the
DMA transfer. This device is referred to as the implied I/O device. The other element can be either memory or another I/O
device and is referred to as the addressed I/O device.
The appropriate DMA acknowledge signal for each channel is asserted during the bus cycle.
If the bus policy is “intermittent”, maximum throughput is one transaction every three clock cycles. If bus policy is “continu-
ous”, maximum throughput on the internal core bus is one transaction every two clock cycles.
Since only one address is required in Direct mode, this address is taken from the corresponding ADCAn counter. The DMAC
Channel generates either a read or a write bus cycle according to the setting of DIR bit in DMACNTLn register.
When DIR bit is 0, a read bus cycle from the addressed device is performed, and the data is written to the implied I/O device.
When DIR bit is 1, a write bus cycle to the addressed device is performed, and the data is read from the implied I/O device.
The configuration of either address freeze or address update (increment or decrement) is independent of the number of
transferred bytes, transfer direction, or number of bytes in each DMAC transfer cycle. All these can be configured for each
channel by programing the appropriate control register.
The number of bytes transferred in each cycle is taken from TCS bit in DMACNTLn register. After the data item has been
transferred, the BLTCn counter is decremented by one. The ADCAn counter are updated according to INCAn field and ADA
bit in DMACNTLn register.
Channel Usage Mode Enable Control Interrupt
0 USART Receive Indirect USART registers DMA_INT0
1 USART Transmit Indirect USART registers DMA_INT1
2 Reserved Indirect
3 Reserved Indirect
CLK
DMRQi
ADDR
DMACKi
T1 T2 Tidle T1Bus State
ADCA
Embedded Controller Modules (Continued)
Revision 1.07 89 www.national.com
PC87591E/S/L
Indirect (Memory-to-Memory) Transfers
Figure 28. Indirect Bus Cycle (DIR=0) - External Bus
Figure 29. Indirect Bus Cycle (DIR=1) - External Bus
In Indirect (Memory-to-Memory) mode, data transfers use two consecutive bus cycles. The data is first read into a temporary
register and subsequently written into the destination. This mode is slower than Direct (Fly-By) mode, but it provides support
for different source and destination bus widths.
Indirect mode also facilitates block transfers between two memory elements. Each element is an addressed device and can
be either memory or an I/O device.
The appropriate DMA acknowledge signal for each channel is asserted during the Device B bus cycle.
If the bus policy is “intermittent”, maximum, throughput is every five clock cycles. If the bus policy is “continuous”, maximum
throughput is every two clock cycles on the internal core bus (otherwise, it uses four clock cycles).
When DIR bit is 0, the first bus cycle reads data from the source using the ADCAn counter, and the second bus cycle writes
the data into the destination using the ADCBn counter. When DIR bit is 1, the first bus cycle reads data from the source
using the ADCBn counter, and the second bus cycle writes the data into the destination using the ADCAn counter.
The number of bytes transferred in each cycle is taken from TCS bit in DMACNTLn register. After the data item has been
transferred, the BLTCn counter is decremented by one. The ADCAn and ADCBn counters are updated according to INCAn,
INCBn, ADA and ADB fields in DMACNTLn register.
Note:
For transfer operations between two memory areas, see “Software DMA Request” on page 92.
CLK
DMRQi
ADDR
DMACKi
T1 T2 T1 T2Bus State
ADCA ADCB
Tidle
CLK
DMRQi
ADDR
DMACKi
T1 T2 T1 T2Bus State
ADCB ADCA
Tidle
Embedded Controller Modules (Continued)
www.national.com 90 Revision1.07
PC87591E/S/L
4.2.5 Bus Policy
Intermittent Operation Mode
Figure 30. DMAC Direct Bus Cycles in Intermittent Mode, DMRQ Asserted Constantly.
When BPC bit in DMACNTLn is 0, channel n is in Intermittent mode. In this mode, the DMAC channel relinquishes the bus
after each transaction, regardless of the state of its DMA request input. In this way, the DMAC gives the core (and other
DMA channels) a chance to use the bus, even if a DMA device needs the bus for multiple transfers.
Continuous Operation Mode
Figure 31. DMAC Direct Bus Cycles in Continuous Mode - External Bus
When BPC bit in DMACNTLn register is 1, channel n is in Continuous mode. In this mode, a DMAC channel uses the bus
continuously, as long as its request is active and BLTCn > 0. This allows the channel to utilize the full bandwidth of the bus.
The activity of this channel cannot be interrupted by any other internal bus master, including higher priority DMAC channels.
It is the system designer’s responsibility to limit the duration of the DMA request to prevent bus starvation.
CLK
DMRQi
ADDR
DMACKi
T1 T2 T1 T2 TidleBus State
ADCA ADCA
Tidle
Core Cycle Address
CLK
DMRQi
ADDR
DMACKi
T1 T2 T2 Tidle T1Bus State
ADCA
T1
Core Cycle Address ADCA
T2
Embedded Controller Modules (Continued)
Revision 1.07 91 www.national.com
PC87591E/S/L
4.2.6 Operation Modes
The DMAC operates in three different block transfer modes - single transfer, double buffer and auto-initialize. Select the ap-
propriate mode according to the character of the block transfer.
Single Transfer Operation
This mode provides the simplest way to accomplish a single block data transfer.
Initialization
1. Write the two block transfer addresses and byte count into the corresponding ADCAn, ADCBn and BLTCn counters, re-
spectively. The BLTCn counter should be written last.
2. Program the OT bit for Non-Auto-Initialize mode, and clear EOVR bit in DMACNTLn register to 0. Clear to 0 VLD bit in
DMASTATn register.
3. Set CHEN bit in DMACNTLn register to 1; the channel activates and responds to DMAC transfer requests.
Termination
When the BLTCn counter reaches 0:
The transfer operation terminates.
TC bit in DMASTATn register is set to 1, and CHAC is cleared to 0.
A level interrupt is generated (if enabled by ETC bit in DMACNTLn register).
Double Buffer Operation
This mode allows the software to set up the next block transfer specification while the current block transfer proceeds. This
mode is used for preparing the next buffer for use in a multi-buffer operation (e.g., the alternate buffer in a double-buffer
scheme).
Initialization
1. Write the two block transfer addresses and byte count into the ADCAn, ADCBn and BLTCn counters, respectively. The
BLTCn counter should be written last.
2. Program OT bit in DMACNTLn register for Non-Auto-Initialize mode.
3. Set CHEN bit in DMACNTLn register to 1; the channel activates and responds to DMAC transfer requests.
4. While the current block transfer proceeds, write the addresses and byte count for the next block into the ADRAn, ADRBn
and BLTRn registers. The BLTRn register should be written last.
Continuation / Termination
When the BLTCn counter reaches 0:
TC bit in DMASTATn register is set to 1.
A level interrupt is generated (if enabled by ETC bit in DMACNTLn register).
The DMAC channel checks the value of VLD bit.
If VLD bit is 1:
The channel copies the ADRAn, ADRBn and BLTRn values into ADCAn, ADCBn and BLTCn. The BLTCn counter
should be written last.
Clears VLD bit to 0.
Becomes ready to start the next block transfer (on the next DMA request).
If VLD bit is 0:
The transfer operation terminates.
The channel sets OVR bit in DMASTATn register to 1.
Clears CHAC bit to 0.
A level interrupt is generated (if enabled by EOVR bit in DMACNTLn register).
Note:
ADCB and ADRBn are used only in indirect (memory-to-memory)transfer. In Direct (Fly-By) mode, the DMAC does not use
them and therefore does not copy ADRBn into ADCBn.
Embedded Controller Modules (Continued)
www.national.com 92 Revision1.07
PC87591E/S/L
Auto-Initialize Operation
This mode allows the DMAC to continuously fill the same memory area without software intervention.
Initialization
1. Write the two block addresses and byte count into the ADCAn, ADCBn and BLTCn counters, respectively (the BLTCn
counter should be written last); also write them to the ADRAn, ADRBn and BLTRn registers, respectively (the BLTRn
counter should be written last).
2. Program OT bit in DMACNTLn register for Auto-Initialize mode.
3. Set CHEN bit in DMACNTLn register to 1; the channel activates and responds to DMAC transfer requests.
Continuation
When the BLTCn counter reaches 0:
The contents of the ADRAn, ADRBn and BLTRn registers are copied to the ADCAn, ADCBn and BLTCn counters,
respectively. The BLTCn counter should be written last.
The DMAC channel checks the value of TC bit.
If TC bit is 1:
OVR bit in DMASTATn register is set to 1.
A level interrupt is generated (if enabled by EOVR bit in DMACNTLn register).
The operation is repeated.
If TC bit is 0:
TC bit in DMASTATn register is set to 1.
A level interrupt is generated (if enabled by ETC bit in DMACNTLn register).
The operation is repeated.
4.2.7 Software DMA Request
In addition to the DMRQn signals, a DMA transfer request can also be initiated by software. The software DMA transfer re-
quest is used for memory-to-memory block copying (in indirect transfers).
When SWRQ bit in DMACNTLn register is 1, the corresponding DMA channel receives a DMA transfer request. When
SWRQ bit is 0, the software DMA transfer request of the corresponding channel is inactive.
For each channel, use the software DMA transfer request, only when the corresponding DMRQn signal is inactive.
4.2.8 DMAC Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
DMAC Register Map
Note:
Register names with the suffix n, where n = 0 to 3, are duplicated for each channel.
Unless stated otherwise, bits 21 to 31 are reserved in each of the following registers. Double-word (32-bit) registers may be
accessed word-by-word (word aligned).
Mnemonic Register Name Type
ADCAn Device A Address Counter Register R/W
ADRAn Device A Address Register R/W
ADCBn Device B Address Counter Register R/W
ADRBn Device B Address Register R/W
BLTCn Block Length Counter Register R/W
BLTRn Block Length Register R/W
DMACNTLn DMA Control Register R/W
DMASTATn Status Register R/W
Embedded Controller Modules (Continued)
Revision 1.07 93 www.national.com
PC87591E/S/L
Device A Address Counter Register (ADCAn)
A double-word, read/write register. Holds the current address of either the source data item or the destination location, ac-
cording to DIR bit in DMACNTLn register. ADCAn is updated after each transfer cycle by INCAn, INCBn, ADA and ADB in
DMACNTLn register.
Location: Channel 0 - 00 FA0016
Channel 1 - 00 FA2016
Channel 2 - 00 FA4016
Channel 3 - 00 FA6016
Type: R/W
Device A Address Register (ADRAn)
A double-word, read/write register. Holds the starting address of either the next source data block, or the next destination data
area, according to DIR bit in DMACNTLn register.
Location: Channel 0 - 00 FA0416
Channel 1 - 00 FA2416
Channel 2 - 00 FA4416
Channel 3 - 00 FA6416
Type: R/W
Device B Address Counter Register (ADCBn)
A double-word, read/write register. Holds the current address of either the source data item, or the destination location, ac-
cording to DIR bit in DMACNTLn register. ADCBn is updated after each transfer cycle by INCAn, INCBn, ADA and ADB in
DMACNTLn register. In Direct (Fly-By) mode, this register is not used.
Location: Channel 0 - 00 FA0816
Channel 1 - 00 FA2816
Channel 2 - 00 FA4816
Channel 3 - 00 FA6816
Type: R/W
Device B Address Register (ADRBn)
A double-word, read/write register. Holds the starting address of either the next source data block or the next destination
data area, according to DIR bit in DMACNTLn register. In Direct (Fly-By) mode, this register is not used.
Location: Channel 0 - 00 FA0C16
Channel 1 - 00 FA2C16
Channel 2 - 00 FA4C16
Channel 3 - 00 FA6C16
Type: R/W
Bit 313029282726252423222120191817161514131211109876543210
Name Device A Address Counter
Bit 313029282726252423222120191817161514131211109876543210
Name Device A Address
Bit 313029282726252423222120191817161514131211109876543210
Name Device B Address Counter
Bit 313029282726252423222120191817161514131211109876543210
Name Device B Address
Embedded Controller Modules (Continued)
www.national.com 94 Revision1.07
PC87591E/S/L
Block Length Counter Register (BLTCn)
A double-word, read/write register. Holds the current number of DMA transfers to be executed in the current block. BLTCn
is decremented by one after each transfer cycle. A DMA transfer may consist of one or two bytes according to TCS bit in
DMACNTLn register.
Location: Channel 0 - 00 FA1016
Channel 1 - 00 FA3016
Channel 2 - 00 FA5016
Channel 3 - 00 FA7016
Type: R/W
Note: Writing 0 to Block Length Counter field of BLTCn initializes the DMA for 221-1 transfers.
Block Length Register (BLTRn)
A double-word, read/write register. Holds the number of DMA transfers to be executed in the next block. Writing this register,
sets VLD bit in DMASTATn register to 1.
Location: Channel 0 - 00 FA1416
Channel 1 - 00 FA3416
Channel 2 - 00 FA5416
Channel 3 - 00 FA7416
Type: R/W
Note: writing 0 to Block Length field of BLTRn initializes the DMA for 221-1 transfers.
DMA Control Register (DMACNTLn)
A word-wide, read/write register that synchronizes the channel’s operation with the programing of the block transfer param-
eters. On reset, the implemented bits are initialized to 0.
The format of the DMACNTLn register is shown below.
Location: Channel 0 - 00 FA1C16
Channel 1 - 00 FA3C16
Channel 2 - 00 FA5C16
Channel 3 - 00 FA7C16
Type: R/W
Bit 313029282726252423222120191817161514131211109876543210
Name Reserved Block Length Counter
Bit 313029282726252423222120191817161514131211109876543210
Name Reserved Block Length
Bit 15 14 13 12 11 10 9 8
Name Reserved INCB ADB INCA ADA SWRQ
Reset 0000000
Bit 76543210
Name BPC OT DIR IND TCS EOVR ETC CHEN
Reset 00000000
Bit Description
0CHEN (Channel Enable). Must be set to enable DMA operation on this channel
0: Channel disabled
1: Channel enabled
If CHEN bit in DMACNTLn register is cleared in all channels, the DMA clock is disabled to preserve power.
Embedded Controller Modules (Continued)
Revision 1.07 95 www.national.com
PC87591E/S/L
1ETC (Enable Interrupt on Terminal Count). Enables a level interrupt, when TC bit is set.
0: Interrupt masked
1: Interrupt enabled
2EOVR (Enable Interrupt on OVR). Enables a level interrupt, when OVR bit is set.
0: Interrupt masked
1: Interrupt enabled
3TCS (Transfer Cycle Size). Specifies the number of bytes transferred in each DMA transfer cycle. In Direct
(Fly-By) mode, undefined results occur if TCS is not equal to the addressed memory bus width.
0: Byte wide transfer
1: Word-wide (16-bit) transfer
4IND (Direct/Indirect Transfer). Transfer Type.
0: Direct (Fly-By)
1: Indirect (Memory-to-Memory)
5DIR (Transfer Direction). Specifies the direction of the transfer relative to Device A.
0: Device A (pointed to by ADCAn) is the source. In Fly-By mode, a read transaction is initialized.
1: Device A (pointed to by ADCAn) is the destination. In Fly-By mode, a write transaction is initialized.
6OT(Operation Type).
0: Single-Buffer mode or Double-Buffer mode enabled
1: Auto-Initialize mode enabled
7BPC (Bus Policy Control). Intermittent (cycle stealing) or continuous (burst).
0: Intermittent operation. DMAC channel n relinquishes the bus after each transaction even if the request is still
asserted.
1: Continous operation. DMAC channel n uses the bus continuously as long as the request is asserted. This mode
can only be used for SW DMA requests (i.e., when SWRQ is set). On HW DMA requests, BPC must be set to 0.
8SWRQ (Software DMA Request).
0: Software DMA request is inactive
1: Software DMA request is active
9ADA (Device A Address Control). Enables Update of Device A Address.
0: ADCAn address unchanged
1: ADCAn address incremented or decremented, according to INCA field
11-10 INCA (Increment/Decrement ADCAn).
Bits
11 10 Description
0 0: Increment ADCAn register by 1
0 1: Increment ADCAn register by 2
1 0: Decrement ADCAn register by 1
1 1: Decrement ADCAn register by 2
12 ADB (Device B Address Control). Enables Update of Device B Address.
0: ADCBn address unchanged
1: ADCBn address incremented or decremented, according to INCB field
14-13 INCB (Increment/Decrement ADCBn).
Bits
14 13 Description
0 0: Increment ADCBn register by 1
0 1: Increment ADCBn register by 2
1 0: Decrement ADCBn register by 1
1 1: Decrement ADCBn register by 2
15 Reserved.
Bit Description
Embedded Controller Modules (Continued)
www.national.com 96 Revision1.07
PC87591E/S/L
DMA Status Register (DMASTATn)
A byte-wide, read with write 1 to clear register that holds the status information for the DMAC channel. On reset, the imple-
mented bits are initialized to 0. The reserved bits always return zero when read.
The format of the DMASTATn register is shown below.
Location: Channel 0 - 00 FA1E16
Channel 1 - 00 FA3E16
Channel 2 - 00 FA5E16
Channel 3 - 00 FA7E16
Type: R/W1C
Bit 76543210
Name Reserved VLD CHAC OVR TC
Reset 00000000
Bit Description
0TC1(Terminal Count). When set to 1, indicates that the transfer was completed by a terminal count condition
(BLTCn register reached 0).
1. The VLD, OVR and TC bits are sticky (once set by the occurrence of the specific condition, they remain set until
explicitly cleared by software). These bits can be cleared individually by writing a value into the DMASTATn reg-
ister with the bit positions to be cleared set to 1; writing 0 to these bits has no effect.
1OVR1(Channel Overrun).
In double buffered operation (OT bit in DMACNTLn register is 0):
OVR is set to 1 when the present transfer is completed (BLTC = 0), but the parameters for the next transfer
(address and block length) are not valid.
In auto initialize operation: (OT bit in DMACNTLn register is 1)
OVR is set to 1 when the present transfer is completed (BLTC = 0), but TC bit is still set to 1 (e.g., the software
did not serve the last interrupt).
In single buffer operation:
This bit is ignored.
2CHAC (Channel Active). Continuously reflects the active or inactive status of the channel and is therefore read
only. Data written to CHAC bit is ignored.
0: Indicates that the channel is inactive
1: Indicates that the channel is active (CHEN bit in DMACNTLn register is 1 and BLTC > 0)
3VLD1(Transfer Parameters Valid). Specifies whether the transfer parameters for the next block to be
transferred are valid.
Writing to the BLTRn register sets this bit to 1.
It is cleared to 0 in the following cases:
The present transfer is completed, and the ADRAn, ADRBn (Indirect mode only) and BLTR registers are copied
to the ADCAn, ADCBn (Indirect mode only) and BLTCn registers, respectively.
Writing 1 to VLD bit; (writing zero has no effect).
7-4 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 97 www.national.com
PC87591E/S/L
4.2.9 Usage Hints
Do not write to ADCAn, ADCBn or BLTCn and do not change the value of TCS, IND, DIR, OT, ADA, INCA, ADB and
INCB fields of DMACNTLn register while the associated channel is active (CHAC bit in DMASTATn register is 1).
When initializing these registers, write to BLTCn register last, since writing to BLTCn register activates the channel
immediately (if CHEN bit in DMACNTLn register is set to 1).
The ADRAn, ADRBn and BLTRn registers store transfer parameters (source address, destination address and block
length) for the next data block to be transferred, for either Auto-Initialize or Double-Buffer modes of operation. When
initializing these registers, write the BLTRn register last, since this validates the next block’s parameters (VLD bit in
DMASTATn register is set to 1).
The TCS bit in DMACNTLn register is programed according to the bus width of the devices. It determines how many
bytes are transferred in each DMA bus cycle.
The DMAC does not support non-aligned transfers. The values written to ADCAn, ADRAn, ADCBn and ADRBn must
be multiples of the Transfer Cycle Size (as defined by TCS bit in DMACNTLn register).
Embedded Controller Modules (Continued)
www.national.com 98 Revision1.07
PC87591E/S/L
4.3 INTERRUPT CONTROL UNIT (ICU)
The ICU has 31 channels. It interfaces between the different modules’ interrupt requests and external interrupt requests and
also generates the core interrupt. It generates both maskable and non-maskable interrupts. The ICU has a predetermined
scheme that allocates priority.
4.3.1 Features
Non-Maskable Interrupts (NMI)
Gathers all edge-triggered non-maskable interrupt sources
External Power Fail (PFAIL) interrupt source
Holds the status of the current pending NMI requests
Generates non-maskable interrupt (NMI) to the core
Maskable Interrupts
31 active high-level or edge-triggered interrupt sources
Core vectored interrupt mode
Fixed priority among interrupt sources
Individual enable/disable for each interrupt source
Polling support by an interrupt status register
Clear registers for edge-triggered interrupts
4.3.2 Non-Maskable Interrupt (NMI)
The Interrupt Control Unit (ICU) gathers external non-maskable interrupt (NMI) sources and generates an NMI interrupt to
the core when required.
External NMI Inputs
The ICU processes the PFAIL signal to send to the CR16B NMI input.
Non-Maskable Interrupt Processing
The CR16B core performs an “Interrupt Acknowledge” bus cycle when beginning to process a non-maskable interrupt. The
address associated with this core bus cycle is within the internal core address space and may be monitored as a Core Bus
Monitoring (CBM) clock cycle. For additional details, see “Core Bus Monitoring” on page 82 and Section 4.20.6 on page 273.
After reset, NMI is disabled and must remain disabled until the software initializes the interrupt table, interrupt base and the
interrupt mode.
The PFAIL interrupt is enabled by setting ENLCK bit and remains enabled until a reset occurs. This allows the external NMI
feature to be enabled only after the Interrupt Base Register (IMASK) and the Interrupt Stack Pointer (ISP), in the core, have
been set up.
Alternatively, the external PFAIL interrupt can be enabled by setting EN bit, which remains enabled until an interrupt event
or a reset occurs. The NMISTAT register holds the status of the current pending NMI request. When the bit in NMISTAT is
set to 1, an NMI request to the core is issued. NMISTAT is cleared each time its contents are read. NMI handlers must read
the NMISTAT register to allow new NMI events to occur.
Note that PFAIL status bit in NMISTAT register may be set as a result of transient enable conditions on PFAIL. To avoid an
interrupt to the core, after configuring the PFAIL input for operation, read the NMISTAT register and then enable PFAIL by
writing 1 to EN bit in PFAIL register.
PFAIL Input
The PFAIL signal is an asynchronous input with Schmitt trigger characteristics and an internal synchronization circuit; there-
fore, no external synchronizing circuit is needed. The PFAIL signal generates an interrupt on its falling edge.
4.3.3 Maskable Interrupts
The ICU receives level or edge-triggered interrupt request signals from 31 sources and generates a vectored interrupt to the
CR16B core when required. Priority among the interrupt sources (named INT1 to INT31) is fixed. Each interrupt source can
be individually enabled or disabled under software control through:
ICU interrupt enable registers
Interrupt enable bits in the peripherals that request the interrupts.
Embedded Controller Modules (Continued)
Revision 1.07 99 www.national.com
PC87591E/S/L
Pending interrupts, enabled or disabled, can be polled using the Status registers. The CR16B core supports INT0, but the
ICU reserves INT0 so that it is not connected to any interrupt source.
Maskable Interrupt Vectors
Interrupt vector numbers are always positive and are in the range 1016 to 2F16. The IVCT register contains the interrupt vec-
tor of the enabled and pending interrupt with the highest priority. The interrupt vector 1016 corresponds to INT0 with the low-
est priority; the vector 2F16 corresponds to INT31 with the highest priority.
The CR16B core performs an “Interrupt Acknowledge” bus cycle on receiving an enabled maskable interrupt request from
the ICU. During the interrupt acknowledge cycle, a byte is read from address 00 FE0016 (IVCT register). The byte read is
used as an index in the Dispatch Table to determine the address of the interrupt handler.
Although INT0 is not connected to any interrupt source, the IVCT register can return the value 1016. This happens, for ex-
ample, when the interrupt request is removed before the interrupt acknowledge cycle. The entry in the Dispatch Table should
point to a default interrupt handler that handles this error condition.
Pending Interrupts
Edge-triggered interrupts are latched by the Interrupt Status register. A pending edge-triggered interrupt is cleared by writing
a ‘1’ to the respective bit in the Edge Interrupt Clear register, IECLR0 or IECLR1.
A pending level-triggered interrupt is cleared when the interrupt source is not active; note that the interrupt should be cleared
at the device/module that drives it by clearing the event status bit.
Interrupt mask bits (IENAM register bits) and pending interrupt bits (ISTAT register bits), should be cleared to 0 only when
interrupts are disabled; i.e., when bits I and/or E in PSR register (a core register) are 0. Bits in IENAM may be set at any time.
Interrupt Priorities
The priorities of the maskable interrupts are hard-wired and thus fixed. The interrupts are named INT0 to INT31, where INT0
has the lowest priority and INT31 has the highest priority.
Power-Down Modes
Interrupt sources that may generate unexpected interrupts in Idle mode should be masked before switching to the power-
down mode.
External Interrupt Inputs
When an MIWU input is disabled, and the respective WKOxx output at the MIWU is connected to the ICU, the MIWU input
is fed directly to the ICU. In this case, the interrupt inputs are asynchronous. They are recognized by the PC87591x during
cycles in which the input setup and hold time requirements are satisfied. To use an external interrupt which is shared with
an I/O port, configure the I/O port to its alternate function (see Section 2.4 on page 54).
Interrupt Assignment
Table 16 shows the mapping of the ICU maskable interrupts to different functions. For information on mask bits and the clear
mechanism for the status bit in internal level interrupts, refer to descriptions of the module that is the interrupt source.
Table 16. ICU Interrupt Assignments
INT
Number Source Type Details Priority
INT0 - - Error condition occurred (spurious interrupt) Lowest
INT1 External/MIWU Level-High External Interrupt EXWINT20 through the MIWU1
INT2 Internal Level-High Host I/F Keyboard/Mouse channel Output Buffer Empty
INT3 Internal Level-High Host I/F Power Management channel 1 or channel 2 Output
Buffer Empty
INT4 Internal Level-High High-Frequency Clock Generator
INT5 Internal Level-High MIWU PSWUINT or WKINTD
INT6 External/MIWU Level-High External Interrupt EXWINT23 through the MIWU1
INT7 Internal Level-High MFT16 1 Interrupt (INT1 ORed with INT2)
Embedded Controller Modules (Continued)
www.national.com 100 Revision1.07
PC87591E/S/L
INT8 Internal Level-High ADC interrupt (ADCI)
INT9 Internal Level-High ACCESS.bus 1 interrupt
INT10 Internal Level-High ACCESS.bus 2 interrupt
INT11 MIWU Level-High Internal Keyboard Scan Interrupt (KBSINT from MIWU) or
ACM Interrupt
INT12 Internal/MIWU Level-High MSWC interrupt through the MIWU
INT13 Internal/MIWU Edge Rising TWM system tick (T0OUT), through the MIWU2
INT14 External/MIWU Level-High SWIN input1, through the MIWU
INT15 Reserved
INT16 Internal Level-High USART Interrupt (TX Int OR RX int)
INT17 External/MIWU Level-High External Interrupt EXWINT24 through the MIWU1
INT18 Internal Edge Falling PS/2 shift mechanism (PSINT3)
INT19 Internal Edge Falling PS/2 shift mechanism (PSINT2)
INT20 Internal Level High /
Edge Falling3PS/2 shift mechanism (PSINT1)
INT21 External/MIWU Level-High External Interrupt EXWINT22 through the MIWU1
INT22 Internal Level-High MFT16 2 Interrupt (INT1 ORed with INT2)
INT23 Internal Level-High Flash I/F interrupt or
Shared Memory Interrupt
INT24 Internal Level-High Host I/F Keyboard/Mouse channel Input Buffer Full
INT25 Internal Level-High Host I/F Power Management channel 1 or channel 2 Input
Buffer Full
INT26 Reserved
INT27 Internal Level-High DMA Channel 0
INT28 Internal Level-High DMA Channel 1
INT29 Reserved
INT30 Reserved
INT31 External/MIWU Level-High External Interrupt EXWINT21 through the MIWU1Highest
1. To enable the external interrupt, set the pin to its alternate function. When used as I/O port signals the External
interrupt input is forced to 0
2. When in Active mode, it is advised to disable the T0OUT channel of the MIWU, this saves the need to clear the
pending bit in the MIWU on each interrupt.
3. Falling Edge is enabled for this input when the PS/2 channel ‘Disabled Shift Mechanism Interrupts’ are enabled
(DSMIE in PSIEN register = 1)
Table 16. ICU Interrupt Assignments (Continued)
INT
Number Source Type Details Priority
Embedded Controller Modules (Continued)
Revision 1.07 101 www.national.com
PC87591E/S/L
4.3.4 ICU Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
ICU Register Map
Interrupt Vector Register (IVCT)
The IVCT register holds the vector number of the interrupt vector. IVCT is set to 1016 on reset.
Location: 00 FE0016
Type: RO
NMI Status Register (NMISTAT)
The NMISTAT register holds the status of the current pending Non-Maskable Interrupt (NMI) requests. This register is cleared
on reset and each time its contents are read. Refer to the description of the PFAIL register below for additional details.
Location: 00 FE0216
Type: RO
Mnemonic Register Name Type
IVCT Interrupt Vector RO
NMISTAT NMI Status RO
PFAIL Power Fail Interrupt Control and Status R/W
ISTAT0 Interrupt Status 0 RO
ISTAT1 Interrupt Status 1 RO
IENAM0 Interrupt Enable and Mask 0 R/W
IENAM1 Interrupt Enable and Mask 1 R/W
IECLR0 Edge Interrupt Clear 0 WO
IECLR1 Edge Interrupt Clear 1 WO
Bit 76543210
Name 0 0 INTVECT
Reset 00010000
Bit Description
5-0 INTVECT (Interrupt Vector). Contains the encoded value of the enabled pending interrupt with the highest
priority; the valid values range from 1016 to 2F16. Valid during an interrupt acknowledge core bus cycle in which
IVCT is read. It may contain invalid data when INTVECT is updated.
7-6 These bits return 0 when read.
Bit 76543210
Name Reserved EXT
Reset 00000000
Bit Description
0EXT (External Non-Maskable Interrupt Request).
0: No external non-maskable interrupt request occurred
1: External non-maskable interrupt request occurred
7-1 Reserved.
Embedded Controller Modules (Continued)
www.national.com 102 Revision1.07
PC87591E/S/L
Power Fail Interrupt Control and Status Register (PFAIL)
The PFAIL register holds the current value of the PFAIL signal and controls the NMI interrupt generation based on a falling
edge of the PFAIL signal. EN and ENLCK are cleared on reset. When writing to this register, all reserved bits must be written
with 0 for the device to function properly.
Location: 00 FE0416
Type: R/W
Interrupt Status Register 0 (ISTAT0)
This register indicates which maskable interrupts are pending regardless of the state of the corresponding IENA bits. ISTAT0
is cleared on reset.
Location: 00 FE0A16
Type: RO
Bit 76543210
Name Reserved ENLCK PIN EN
Reset xxxx00x0
Bit Description
0EN (PFAIL Interrupt Enable). An NMI interrupt is generated when this bit is set to 1 and the PFAIL signal
changes its value from high to low. The bit is cleared by hardware on reset and whenever the interrupt occurs
(i.e., when EXT bit in NMISTAT register is set). It can be set and cleared by software; however, software can set
this bit only when EXT is cleared. This bit is ignored when ENLCK is set.
0: No NMI interrupt generated
1: NMI interrupt generated
1PIN (PFAILPin Value). Contains the current (non-inverted) PFAIL signal value. This bit is read only; data written to
it is ignored.
2ENLCK PFAIL Interrupt Enable Lock. When this bit is set to 1, the external PFAIL feature is enabled and
locked; it cannot be cleared by software and can only be cleared by hardware on reset. After setting this bit, an
NMI interrupt is generated every time the PFAIL signal changes its value from high to low. Note that when
ENLCK is set, EN bit is ignored.
0: External PFAIL feature disabled
1: External PFAIL feature enabled and locked
7-3 Reserved.
Bit 1514131211109876543210
Name IST15-0
Reset 0 000000000000000
Bit Description
15-0 IST15-0 (Interrupt Status). Each bit indicates if an interrupt event was sent to the ICU; IST15 to IST0
correspond to INT15 to INT0, respectively. Since INT0 is not used, IST0 always reads 0. Each bit is encoded
as follows:
0: Interrupt input to ICU not pending
1: Interrupt input to ICU pending
Embedded Controller Modules (Continued)
Revision 1.07 103 www.national.com
PC87591E/S/L
Interrupt Status Register 1 (ISTAT1)
This register indicates which maskable interrupts are pending regardless of the state of the corresponding IENA bits.
Location: 00 FE0C16
Type: RO
Interrupt Enable and Mask Register 0 (IENAM0)
This register controls the enable/disable of the maskable interrupt sources INT0 to INT15. The register is cleared (000016)
on reset.
Location: 00 FE0E16
Type: R/W
Interrupt Enable and Mask Register 1 (IENAM1)
This register controls the enable/disable of the maskable interrupt sources INT16 to INT31. The register is cleared (000016)
on reset.
Location: 00 FE1016
Type: R/W
Bit 1514131211109876543210
Name IST31-16
Reset 0 000000000000000
Bit Description
15-0 IST31-16 (Interrupt Status). Each bit indicates if an interrupt event was sent to the ICU; IST31 to IST16
correspond to INT31 to INT16, respectively. Each bit is encoded as follows:
0: Interrupt input to ICU not pending
1: Interrupt input to ICU pending
Bit 1514131211109876543210
Name IENA15-0
Reset 0 000000000000000
Bit Description
15-0 IENA15-0 (Interrupt Enable). Each bit enables or disables the corresponding interrupt request INT0 to INT15;
e.g. IENA15 controls INT15. Since INT0 is not used, IENA0 has no effect on the operation of the ICU.
0: Interrupt disabled
1: Interrupt enabled
Bit 1514131211109876543210
Name IENA31-16
Reset 0 000000000000000
Bit Description
15-0 IENA31-16 (Interrupt Enable). Each bit enables or disables the corresponding interrupt request INT16 to
INT31; e.g. IENA16 controls INT16.
0: Interrupt disabled
1: Interrupt enabled
Embedded Controller Modules (Continued)
www.national.com 104 Revision1.07
PC87591E/S/L
Edge Interrupt Clear Register 0 (IECLR0)
The IECLR register is used to clear pending, edge-triggered interrupts.
Location: 00 FE1216
Type: WO
Edge Interrupt Clear Register 1 (IECLR1)
The IECLR register is used to clear pending, edge-triggered interrupts.
Location: 00 FE1416
Type: WO
4.3.5 Usage Hints
Initializing
The recommended initialization sequence is:
1. Initialize both the INTBASE register and the interrupt stack pointer of the core.
2. Prepare the interrupt routines of the interrupts used.
3. Clear edge interrupt used.
4. Set relevant bits of the peripherals.
5. Set relevant bits in IENAM register.
6. Set PFAIL register.
7. Enable core interrupt.
Clearing
Clearing an interrupt request before it is serviced may cause a spurious interrupt (i.e., when the core detects an interrupt not
reflected by IVCT). Clear interrupt requests only when interrupts are disabled. Clear IENAM bits and ISTAT bits while the
core interrupts are disabled (i.e., bits I and/or E in PSR register are cleared).
Nesting
The IENAM registers can be used in interrupt handlers to allow interrupt nesting. When the core acknowledges an interrupt, it
disables maskable interrupts by clearing bit I in PSR register and executes the interrupt service routine. This routine can enable
nested interrupts by setting bit I in PSR register and can use the IENAM registers to control which interrupts are allowed.
Bit 1514131211109876543210
Name IEC15-1 Res.
Bit Description
0Reserved.
15-1 IEC15-1 (Edge Interrupt Clear). Each bit clears the corresponding bit in ISTAT0 register. Writing to the bit
positions of level-triggered interrupts has no effect. Read always returns FFFF16. IEC15 to IEC1 correspond to
INT15 to INT1, respectively. Each bit is encoded as follows:
0: No effect
1: Pending edge-triggered interrupt cleared
Bit 1514131211109876543210
Name IEC31-16
Bit Description
15-0 IEC31-16 (Edge Interrupt Clear). Each bit clears the corresponding bit in ISTAT1 register. Writing to the bit
positions of level-triggered interrupts has no effect. Read always returns FFFF16. IEC31 to IEC16 correspond to
INT31 to INT16, respectively. Each bit is encoded as follows:
0: No effect
1: Pending edge-triggered interrupt cleared
Embedded Controller Modules (Continued)
Revision 1.07 105 www.national.com
PC87591E/S/L
4.4 MULTI-INPUT WAKE-UP (MIWU)
The Multi-Input Wake-Up Unit (MIWU) allows the PC87591x to exit Idle mode. In addition, it provides signal conditioning and
grouping of external interrupt sources. It supports a total of 32 internal and/or external wake-up sources.
4.4.1 Features
Supports up to 32 internal and/or external wake-up inputs
Generates a wake-up signal
Generates interrupt signals for:
each of the 32 inputs
one interrupt for each group of eight inputs e.g., I/O ports
User-selectable trigger condition on each input:
positive edge
negative edge
Individual enable and pending bits for each input
Programmable bypass mode connects inputs to ICU without MIWU involvement
4.4.2 Operation
Overview
The Multi-Input Wake-Up Unit (MIWU) detects a valid software-selectable trigger condition on any of its inputs. On detection
of a valid trigger condition, the MIWU generates a wake-up request and/or an interrupt request. The wake-up request is con-
nected to the Power Management module (PMC) and may be utilized to exit the Idle mode and return to Active mode. The
interrupt requests are used to signal to the Interrupt Control Unit (ICU) that either an edge-triggered external or internal in-
terrupt condition has occurred. Figure 32 shows a block diagram of the Multi-Input Wake-Up module.
Note that the MIWU module is active while in Idle mode. Note, however, that because all device clocks are stopped in Idle
mode, the detection of a trigger condition on an input, and the resulting set of the pending flag, are not synchronous to the
system clock.
Table 17 lists the MIWU sources and interrupts used in the PC87591x.
Table 17. Input Assignments
Source Destination
Name MIWU Input Interrupt Name MIWU Output
PSCLK1 WUI10 PSWUINT WKINTA
PSCLK2 WUI11
PSCLK3 WUI12
PSDAT1 WUI13
PSDAT2 WUI14
PSDAT3 WUI15
PSCLK4 WUI16
PSDAT4 WUI17
EWXINT20 WUI20 INT1 WKO20
EXWINT21 WUI21 INT31 WKO21
EXWINT22 WUI22 INT21 WKO22
EXWINT23 WUI23 INT6 WKO23
EXWINT24 WUI24 INT17 WKO24
SWIN WUI25 INT14 WKO25
MSWC Wake-Up WUI26 INT12 WKO26
T0OUT1WUI27 T0OUTINT WKO27
Embedded Controller Modules (Continued)
www.national.com 106 Revision1.07
PC87591E/S/L
KBSIN0 WUI30 KBSINT WKINTC
KBSIN1 WUI31
KBSIN2 WUI32
KBSIN3 WUI33
KBSIN4 WUI34
KBSIN5 WUI35
KBSIN6 WUI36
KBSIN7 WUI37
EXWINT40 WUI40 MIWU2 WKINTD
Reserved WUI41
Host Access Wake-Up2WUI42
ACCESS.bus 1 Wake-Up1WUI43
ACCESS.bus 2 Wake-Up1WUI44
EXWINT45 WUI45
EXWINT46 WUI46
Analog Comparators (ACMI) WUI47
1. Program the input to detect the rising edge of the input event.
2. The wake-up input is triggered by a host access to one of a selected set of
devices in the PC87591x. See “Core Interrupt” on page 343. Configure the
WUI26 for rising edge detection.
Table 17. Input Assignments (Continued)
Source Destination
Name MIWU Input Interrupt Name MIWU Output
Embedded Controller Modules (Continued)
Revision 1.07 107 www.national.com
PC87591E/S/L
Trigger Conditions
Through the WKEDGx registers, the trigger condition on the selected input signal can be selected as either positive edge
(low-to-high transition) or negative edge (high-to-low transition).
Peripheral Bus
70
WKEN1
0
7
..........................
WUI30
Wake-Up Signal to
Power Management
WKINTA
WUI20
WUI27
WUI10
WUI17
0
7
WKEDG1 WKPND1 1
0
0
1
SEL
SEL
WKO10
WKO17
.
...
Interrupt
Control
Unit
Power
Management
WKUP Inputs Group 1
WKUP Inputs Group 3
(Uses registers WKEDG3, WKPND3 and WKEN3)
WUI37 WKO30
WKO37
WKINTC
WUI40
WKUP Inputs Group 4
(Uses registers WKEDG4, WKPND4 and WKEN4)
WUI47 WKO40
WKO47
WKINTD
Figure 32. Multi-Input Wake-Up Block Diagram
WKUP Inputs Group 3
(Uses registers WKEDG2, WKPND2 and WKEN2)
WKO20
WKO27
WKINTB
(ICU)
Module
to
to
to
to
Note: Not all MIWU-ICU connections are implemented; for details,
see ICU interrupt assignments in Table 17 on page 105.
Embedded Controller Modules (Continued)
www.national.com 108 Revision1.07
PC87591E/S/L
Pending Flags
An occurrence of a trigger condition for the Multi-Input Wake-Up input is latched into the respective pending bit in WKPNDx
register. The respective bits of WKPNDx are set on an occurrence of the selected trigger edge on the corresponding input
signal.
Since the WKPNDx register holds a pending wake-up condition until it is cleared, the device does not enter the IDLE mode
if any wake-up bit is both enabled and pending. Consequently, the pending flags must be cleared before an attempt to enter
the Idle mode.
Input Enable
The MIWU utilizes multiple Multi-input Wake-Up signals. Setting the appropriate bits in the WKENAx registers select which
particular wake-up signal causes the device to exit Idle mode.
Interrupts
The combined output of all pending and enabled channels of the MIWU module generates the wake-up signal, which is fed
into both the Power Management Control module (PMC) and the Interrupt Control Unit (ICU). Therefore, each wake-up of
the device can be followed by a wake-up interrupt. Since the device can not enter the power reduction mode without having
the core execute a “WAIT” instruction, a wake-up interrupt is needed to terminate the “WAIT” instruction on wake-up.
MIWU outputs WKO10 through WKO37 may be connected to the Interrupt Control Unit (ICU) to generate an interrupt asso-
ciated with the specific MIWU output. The WKOxx behaves as follows:
When the respective WKENxx bit is cleared, the WUIxx is connected to the ICU directly (bypassing the edge detec-
tors and pending bits). The ICU can be configured to use the signal as a level or edge triggered interrupt.
When the respective WKENxx bit is enabled, the output of the pending bit, WKPDxx, is connected to WKOxx.
Note: To enable and disable ICU interrupts generated by their associated WKOxx output of the MIWU, use the ICU mask
register in the ICU.
In addition, the MIWU provides four interrupt request lines: WKINTA, WKINTB, WKINTC and WKINTD (see Figure 32 on
page 107). These are routed to the ICU (except WKINTB) and can request an interrupt if a valid trigger condition occurred
on any of the enabled input sources within the group of eight inputs associated with the interrupt line. For a detailed summary
of the interrupts available, see Table 17 on page 105.
Embedded Controller Modules (Continued)
Revision 1.07 109 www.national.com
PC87591E/S/L
4.4.3 MIWU Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
MIWU Register Map
Edge Detection Register (WKEDG1)
Byte-wide read/write register that configures the trigger condition of the input signals WUI10 to WUI17. The register is
cleared on reset. This configures all associated input signals to be triggered on a rising edge.
Location: 00 FFC016
Type: R/W
Mnemonic Register Name Type
WKEDG1 Edge Detection Register R/W
WKEDG2 Edge Detection Register R/W
WKEDG3 Edge Detection Register R/W
WKEDG4 Edge Detection Register R/W
WKPND1 Pending Register R/W
WKPND2 Pending Register R/W
WKPND3 Pending Register R/W
WKPND4 Pending Register R/W
WKEN1 Enable Register R/W
WKEN2 Enable Register R/W
WKEN3 Enable Register R/W
WKEN4 Enable Register R/W
WKPCL1 Pending Clear Register WO
WKPCL2 Pending Clear Register WO
WKPCL3 Pending Clear Register WO
WKPCL4 Pending Clear Register WO
Bit 76543210
Name WKED17-WKED10
Reset 00000000
Bit Description
7-0 Edge Selection. For inputs WUI10 through WUI17. Each bit is associated with one of eight inputs.
0: Low-to-High transition.
1: High-to-Low transition.
Embedded Controller Modules (Continued)
www.national.com 110 Revision1.07
PC87591E/S/L
Edge Detection Register (WKEDG2)
Byte-wide read/write register that configures the trigger condition of the input signals WUI20 to WUI27. The functionality of
the register is identical to the WKEDG1 register described above.
Location: 00 FFC216
Type: R/W
Edge Detection Register (WKEDG3)
Byte-wide read/write register that configures the trigger condition of the input signals WUI30 to WUI37. The functionality of
the register is identical to the WKEDG1 register described above.
Location: 00 FFC416
Type: R/W
Edge Detection Register (WKEDG4)
Byte-wide read/write register that configures the trigger condition of the input signals WUI40 to WUI47. The functionality of
the register is identical to the WKEDG1 register described above.
Location: 00 FFC616
Type: R/W
Pending Register (WKPND1)
Byte-wide read/write register that latches the occurrence of a selected trigger condition associated with the input signals
WUI10 to WUI17. On reset, the WKPND1 register is cleared (0). This indicates that no occurrence of the selected trigger
condition is pending.
Note: Only software can set the register bits; only the WKPCL1 register can clear them. Writing a 0 to any of the bits leaves
their values unchanged. The WKPND1 register format is shown below:
Location: 00 FFC816
Type: R/W
Pending Register (WKPND2)
Byte-wide read/write register that latches the occurrence of a selected trigger condition associated with the input signals
WUI20 to WUI27. For a detailed description of the register see the above description of the WKPND1 register.
Location: 00 FFCC16
Type: R/W
Pending Register (WKPND3)
Byte-wide read/write register that latches the occurrence of a selected trigger condition associated with the input signals
WUI30 to WUI37. For a detailed description of the register see the above description of the WKPND1 register.
Location: 00 FFD016
Type: R/W
Bit 76543210
Name WKPD17-WKPD10
Reset 00000000
Bit Description
7-0 Wake-Up Pending. If set, (1) indicates that a valid trigger condition occurred on the associated input.
Embedded Controller Modules (Continued)
Revision 1.07 111 www.national.com
PC87591E/S/L
Pending Register (WKPND4)
Byte-wide read/write register that latches the occurrence of a selected trigger condition associated with the input signals
WUI40 to WUI47. For a detailed description of the register see the above description of the WKPND1 register.
Location: 00 FFD416
Type: R/W
Enable Register (WKEN1)
Byte-wide read/write register that enables the wake-up function of the associated input signal, WUI10 to WUI17. On reset,
WDENA1 is cleared (0); this disables the associated input signals. The WKENA1 register format is shown below:
Location: 00 FFD816
Type: R/W
Enable Register (WKEN2)
Byte-wide read/write register that enables the wake-up function of the associated input signal, WUI20 to WUI27. For a de-
tailed description of the register, see the above description of the WKEN1 register.
Location: 00 FFDA16
Type: R/W
Enable Register (WKEN3)
Byte-wide read/write register that enables the wake-up function of the associated input signal, WUI30 to WUI37. For a de-
tailed description of the register, see the above description of the WKEN1 register.
Location: 00 FFDC16
Type: R/W
Enable Register (WKEN4)
Byte-wide read/write register that enables the wake-up function of the associated input signal, WUI40 to WUI47. For a de-
tailed description of the register, see the above description of the WKEN1 register.
Location: 00 FFDE16
Type: R/W
Pending Clear Register (WKPCL1)
Byte-wide write-only register that controls the clearing (0) of the pending bits associated with the WUI10 through WUI17 in-
puts. This avoids potential hardware/software collisions during read-modify-write operations. The WKPCL1 register format
is shown below:
Location: 00 FFCA16
Type: WO
Bit 76543210
Name WKEN17-WKEN10
Reset 00000000
Bit Description
7-0 Wake-Up Enable. If set (1), a valid trigger condition on the associated input generates a wake-up signal or
EXTINTx interrupt request
Bit 76543210
Name WKCL17-WKCL10
Bit Description
7-0 Clear Pending Flag. If a 1 is written to any bit, the associated pending flag located in WKPND1 is cleared (0).
Writing a 0 to any bit leaves the value of the corresponding pending flag unchanged.
Embedded Controller Modules (Continued)
www.national.com 112 Revision1.07
PC87591E/S/L
Pending Clear Register (WKPCL2)
Controls the clearing (0) of the pending bits associated with the WUI20 through WUI27 inputs. For a detailed description of
the register see, the above description of the WKPCL1 register.
Location: 00 FFCE16
Type: WO
Pending Clear Register (WKPCL3)
Controls the clearing (0) of the pending bits associated with the WUI30 through WUI37 inputs. For a detailed description of
the register, see the above description of the WKPCL1 register.
Location: 00 FFD216
Type: WO
Pending Clear Register (WKPCL4)
Controls the clearing (0) of the pending bits associated with the WUI40 through WUI47 inputs. For a detailed description of
the register, see the above description of the WKPCL1 register.
Location: 00 FFD616
Type: WO
4.4.4 Usage Hints
1. When changing an edge select, perform the following steps to avoid a spurious wake-up condition, which may occur as
a result of the edge change:
a. Clear the associated WKENxx bit.
b. Select the required the edge in the WKEDGx register.
c. Clear the associated WKPDxx bit.
d. Re-enable the associated WKENxx bit.
2. The correct use of the Multi-Input Wake-Up circuit, which avoids false triggering of a wake-up condition, requires the
following sequence of actions. Use the same procedure following a Reset since the wake-up inputs are left floating, pro-
ducing unknown data on the MIWU input signals.
a. If the input originates from an I/O port, write to the port alternate function and, if required, direction register to set the
pin to interrupt inputs.
b. Clear the WKENAx register or, if a WKOxx interrupt is used, disable the interrupt via the ICU.
c. Write the WKEDGx register to select the desired type of edge sensitivity for each of the pins used.
d. Clear the WKPNDx register to cancel any pending bits.
e. Eithersetthe WKENxx bits associated with the pins to be used, thus enabling them for the wake-up/interrupt function,
or re-enable the interrupt via the ICU.
3. On Reset, the WKEDGx registers are configured to select positive edge sensitivity for all wake-up inputs. To change the
edge sensitivity of an input signal while preventing the false triggering of a wake-up/interrupt condition, use the following
procedure.
a. Clear the WKENxx bit associated with the WUIxx input to disable that input.
b. Write to the WKEDGx register to select the new type of edge sensitivity for the specific input.
c. Clear the WKPDxx bit associated with the WUIxx input.
d. Set the WKENxx bit associated with the WUIxx input to re-enable it.
Embedded Controller Modules (Continued)
Revision 1.07 113 www.national.com
PC87591E/S/L
4.5 GENERAL-PURPOSE I/O (GPIO) PORTS
The PC87591x includes four types of General-Purpose I/O (GPIO) ports: Px, Py, Pz and Pw.
Px signals: Each signal is bidirectional and can be configured as input or output. An internal weak pull-up is provided
to hold the pin high when used as an input or in an open-drain scheme.
Py signals: Each signal is input only. An internal weak pull-up is provided to hold the pin high.
Pz signals: Each signal is output only. It may be configured to work as totem-pole or in an open-drain scheme.
Pw signals: Each signal is bidirectional and can be configured for input or output. The Pw pins may be shared with
development system functions. These ports can be implemented off-chip in DEV environment using external logic.
The GPIO signals are organized in ports. Each port is either 8-bits or 16-bits wide. In ports where not all eight bits are used,
some of the register’s bits are reserved. Some GPIO signals share their pins with one or more alternate functions. A config-
uration bit selects which function is active (see Section 2.4 on page 54).
Note: Some GPIO signals are only available in a 176-pin package.
GPIO Port Functionality
The PC87591x provides 117 GPIO pins in the 176-pin package and 84 GPIO pins in the 128-pin package. They are subdi-
vided into the following groups:
Ports IOPA(7-0), IOPB(7-0), IOPC(7-0), IOPD(7-0) and IOPF(7-0)
These ports are on-chip, General-Purpose Input/Output (GPIO) ports (type Px).
IOPC0 is reserved for power supply control use. Bit 0 of PCALT, PCDIR, PCWPU and PCDOUT are reset on VCC Power-
Up reset and WATCHDOG reset only.
PB5 and PB6 have an option for automatic TRI-STATE based on LPCPD. See “MSWC Control Status Register 3
(MSWCTL3)” on page 330 for the enable function.
PB6 is selected to its alternate function, by default (i.e., bit 6 is set to 1).
Ports IOPA4-0, IOPB2-0, IOPC0 and IOPD3 have the option to echo the value of the associated input. For the exact
echo matrix specifications, see Section 2.4.3 on page 59.
Bit 5 of PBALT register, bit 0 of PCALT register and bits 4-7 of PDALT register are read only (RO) and return a value of
zero.
IOPE(7-0) and KBSIN(7-0)
These are General-Purpose Input (GPI) ports (type Py). IOPE(3-0) and IOPE5 do not implement the pull-up function,
and the respective bits in PEWPU are reserved. KBSIN has no alternate function; thus it has no PyALT register.
KBSOUT(15-0)
This is a 16-bit General-Purpose Output (GPO) port (type Pz). Since KBSOUT has no alternate functions, its alter-
nate function register is not implemented. The reset value of KBSOUT register is FFFF16. KBSOUT has open-drain
output drivers.
Ports IOPH(7-0), IOPI(7-0), IOPJ(7-0), IOPK(7-0),IOPL(4-0) and IOPM(7-0)
These ports are on-chip, General-Purpose Input/Output (GPIO) ports (type Pw).
When the analog function is enable, the Read function, for GPIO signals that are multiplexed with analog functions,
is disabled; this affects signals KBSIN(7-0) and IOPE(3-0).
When the BIU function is enabled, the Read function, for GPIO signals that are multiplexed with BIU signals, is dis-
abled; this affects signals PH(7-0), PI(7-0), PJ(1-0), PK(7-0), PL(7-0) and PM(7-0).
Embedded Controller Modules (Continued)
www.national.com 114 Revision1.07
PC87591E/S/L
4.5.1 Features
General-Purpose Input/Output (GPIO) Port (Px).
Each pin functions as input or output signal.
Direction register controls the port direction.
Weak pull-up.
Read-back on all registers.
General-Purpose Input (GPI) Port (Py).
All port pins function as input signals.
Weak pull-up.
Read-back on all control registers.
General-Purpose Output (GPO) Port (Pz).
All pins function as output signals.
Read-back on all registers.
General-Purpose Input/Output (GPIO) Port (Pw).
DEV environment support.
Pins shared with DEV environment signals.
Off-chip implementation supported in DEV environments.
Binary and cycle-by-cycle compatibility between environments.
Each pin functions as input or output signal.
Direction register controls the port direction.
Read-back on all registers.
Each I/O pin can be configured as a GPIO port or as an alternate function.
Some I/O or input pins can provide interrupt functions.
4.5.2 GPIO Port Px
Bidirectional Port with Alternate Function
The GPIO port enables access to input and output pins. It also controls the pin usage either as an I/O port or in its alternate
function. Figure 33 illustrates this functionality.
PIN
Direction
Data Output {
Direction
Register {
Weak Pull-Up
Register
Data Input Register
MUX1
MUX2
Data Out
Alt Device Data
Alt
Alt
Alt Device Direction
Alt
Alt Device Data Input
Data Input Read
Pull-Up
Weak Pull-Up
MUX3
Alternate
Function {
Register PxAlt
(PxWPU)
(PxDIR)
(PxDOUT)
PxDIN
Alt
Figure 33. GPIO Port Px Schematic Diagram
{
Output
Register
Embedded Controller Modules (Continued)
Revision 1.07 115 www.national.com
PC87591E/S/L
Output Buffer
The output buffer is a TRI-STATE buffer. The output type (i.e., CMOS or TTL) and its driving capabilities are described in
Section 2.2 on page 41.
Input Buffer
The I/O port input buffer characteristics are defined in Section 2.2 on page 41.
The input buffer has an enable input. When enabled, the buffer inputs the pin’s logic level to the on-chip modules. When
disabled, the input is blocked to prevent supply leakage currents.
Weak Pull-Up
The weak pull-up is enabled when the corresponding bit of PxWPU is set (1) and the pin is configured as an input port. When
the pin is configured for input, this pull-up can prevent the input from being in an undefined state. When the pin is configured
as an output port, this pull-up is disabled.
Alternate Function
The PxALT controls the use of each of the port pins for GPIO or for the pin’s respective alternate function.
When PxALT bit is cleared (0):
The corresponding pin is used as a GPIO pin.
The output buffer is controlled by the Direction and Data Output registers.
The input buffer is routed to the Data Input register.
In this case, the input buffer is blocked, except when the buffer is actually being read.
The pull-up is enabled when both the PxWPU is set and the device puts the output buffer in TRI-STATE.
When a bit in PxALT is set (1):
The corresponding pin is used for an alternate function (i.e., a signal from/to some other PC87591x module).
The output buffer data and TRI-STATE are controlled by signals from the alternate module.
The input buffer is always enabled when the alternate function is an input; therefore, to minimize current consump-
tion, the signal should be held above VCC0.2 or below GND+0.2V.
The pull-up is enabled when PxWPU is set and the device puts the output buffer in TRI-STATE.
Port Direction
The Port Direction register (PxDIR) controls the direction of the port. If set (1), each bit in the register causes the correspond-
ing port signal to serve as an output port, thus enabling the output buffer.
When cleared, the port serves as an input port signal, thus putting the output buffer in TRI-STATE.
If the corresponding bit in PxWPU is set, it also enables the pull-up.
Data Output
The Data Output (PxDOUT) register holds the data to be driven onto the pin, when the respective pin is configured as GPIO
and its direction is set as output.
Data Input
The Data Input (PxDIN) register returns the current value/state of the pin. This register can always be read.
Open Drain
To use the GPIO pin as an inverting open-drain output buffer, the software should clear the corresponding bit in PxDOUT
register and then use PxDIR register to set the value to the port pin.
When the signal direction is set as output (1), a value of 0 is forced. When the direction is set for input (0), the signal is in
TRI-STATE and is not forced low.
The internal weak pull-up can pull the signal high when it is not forced low, by writing (1) to the corresponding bit of PxWPU.
Input Echo Function
SomeofthePxpinscanecho the value of an input pin. Figure 34 illustrates the modified structure of Px port pins that support
the echo function. The input echo function may be used when the Px pin is configured to operate as a General-Purpose
output pin.
Table 9 on page 60 defines pairs of input ports (Pi) and output ports (Po) and the Echo Enable bit associated with each pair.
When the pair’s Echo Enable bit is set, and if Po is configured as output, the value from the input bit (Pi) is output to the
respective output port (Po). When the pair’s Echo Enable bit is cleared, and if Po is configured as output, the value in
PxDOUT is output to the respective output port.
Embedded Controller Modules (Continued)
www.national.com 116 Revision1.07
PC87591E/S/L
4.5.3 GPI Port Py
Input Only Port with Alternate Function
The General-Purpose Input (GPI) port (Py) contains a subset of the GPIO functions. It can be used as a GPI port or as an
input signal for an alternate function. Figure 35 illustrates its functionality.
Px
MUX1
MUX2
Alt
Alt
Alt
Pull-Up
MUX3
PxAlt
(PxWPU)
(PxDIR)
(PxDOUT)
PxDIN
Alt
Figure 34. GPIO Port Px Output with Echo Schematic Diagram
MUX4
PIN
Echo EN
To MIWU
PIN
Data Out
Register {
Direction Register {
Weak Pull-Up Register
Data In Register
Alt Device Direction
Alt Device Data Input
Data In Read
Alternative Function Register
{
or Py
Px
{
PIN
Data Input Register
MUX3
Alt
Alt Device Data Input
Data Input Read
Weak Pull-Up
Pull-Up
PyAlt
Alternate Function Register
Weak Pull-Up
(PyWPU)
Alt
PyDIN
Figure 35. GPI Port Py Schematic Diagram
{
{
Embedded Controller Modules (Continued)
Revision 1.07 117 www.national.com
PC87591E/S/L
Input Buffer
The input buffer characteristics are defined in Section 2.2 on page 41. The input buffer has an enable input. When enabled,
the buffer inputs the pin’s logic level to the on-chip modules. When disabled, the input is blocked to prevent supply leakage
currents.
Weak Pull-Up
The weak pull-up is enabled when the corresponding bit of PyWPU is set (1). This pull-up can prevent the input from being
in an undefined state.
Alternate Function
PyALT controls the use of each of the port pins for GPI or for the pin’s respective alternate function.
When a PxALT bit is cleared (0):
The corresponding pin is used as a GPI pin.
The input buffer is routed to the Data Input register.
In this case, the input buffer is blocked, except when the buffer is actually being read.
The pull-up is enabled when both the PyWPU is set and the output buffer is put in TRI-STATE.
When a bit in PxALT is set (1):
The corresponding pin is used for an alternate function (i.e., a signal to some other PC87591x module).
The input buffer is always enabled; therefore, to minimize current consumption, the signal should be held above VCC0.2
or below GND+0.2V.)
The pull-up is enabled when both the PyWPU is set and the output buffer is put in TRI-STATE.
Data Input
The Data Input (PyDIN) register returns the current value/state of the pin. This register can always be read.
4.5.4 GPO Port Pz
Output Only Port with Alternate Function
The General-Purpose Output (GPO) port (Pz) is a subset of the GPIO functions. It enables the port to be used as a GPO
port or as an output signal for an alternate function. Figure 36 illustrates its functionality.
Output Buffer
The output buffer is a TRI-STATE buffer. The output type (i.e., CMOS or TTL) and its driving capabilities are described in
Section 2.2 on page 41.
Alternate Function
The PzALT controls the use of each of the port pins for GPO or for the pin’s respective alternate function.
When a PzALT bit is cleared (0):
The corresponding pin is used as a GPO pin.
The output buffer is controlled by the Data Output register.
When a bit in PzALT is set (1):
The corresponding pin is used for an alternate function (i.e., a signal from or to some other module of the PC87591x).
The output buffer data is controlled by signals coming from the alternate module.
PIN
Data Output
Register {
MUX
Alt Device
Alt
PzAlt
Alternate
Function
Register {
Data Out
(PzDOUT)
Alt
Figure 36. GPO Port Pz Schematic Diagram
Data Output
Embedded Controller Modules (Continued)
www.national.com 118 Revision1.07
PC87591E/S/L
Data Output
The Data Out (PzDOUT) register holds the data to be driven onto the pin.
4.5.5 GPIO Port Pw
GPIO Port Signals Shared with Development System Signals
The Pw GPIO port enables access to input and output pins. Depending on the operating environments, some pins of the I/O
ports may be dedicated to functions other than input or output. In this case, low-cost external logic can be used to perform
the I/O functions with binary and cycle-by-cycle compatibility (see Section 4.1.8 on page 80 for details of the Expansion I/O
protocol). The Alternate Functions Table (Table 8 on page 54) defines the environment in which each port is implemented
off-chip and the pin that performs its alternate function.
The I/O Expansion protocol is used to access the off-chip implementation of the port’s registers (PwDIR, PwDOUT, PwDIN),
when the port pins are used by DEV environment. This enables binary compatibility between all environments.
To enable cycle-by-cycle compatibility in all environments, the access time to any of the registers is identical for on-chip and
off-chip implementation of the ports (i.e., as configured for the BIU I/O zone).
Figure 37 illustrates its functionality.
Output Buffer
The output buffer is a TRI-STATE buffer. Its output type (i.e., CMOS or TTL) and its driving capabilities are described in
Section 2.2 on page 41.
Input Buffer
The I/O port input buffer characteristics are defined in Section 2.2 on page 41. The input buffer has an enable input. When
enabled, the buffer inputs the pin’s logic level to the on-chip modules. When disabled, the input is blocked to prevent supply
leakage currents.
Port Direction
The Port Direction register (PwDIR) controls the direction of the port. When set (1), each bit in PwDIR register causes the
corresponding port signal to serve as an output port, thus enabling the output buffer. When cleared, the port serves as an
input port signal, thus putting the output buffer in TRI-STATE.
Data Output
The Data Output (PwDOUT) register holds the data to be driven onto the pin when the corresponding pin is set as GPIO and
its direction is set as output.
Data Input
The Data Input (PwDIN) register returns the current value/state of the pin. This register can always be read.
Open Drain
To use the GPIO pin as an inverting open-drain output buffer, the software should clear the corresponding bit in Data Output
(PwDOUT) register and then use the Direction register to set the value to the port pin.
PIN
Data Output
Register {
Direction
Register {
Data Input Register
Data Input Read
Data Out
(PwDOUT)
Direction
(PwDIR)
PwDIN
Figure 37. GPIO Port Pw Schematic Diagram
Embedded Controller Modules (Continued)
Revision 1.07 119 www.national.com
PC87591E/S/L
When the signal’s direction is set as output (1), a value of 0 is forced. When the direction is set for input (0), the signal is in
TRI-STATE and is not forced low.
4.5.6 GPIO Port Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
GPIO Register Map
Port Alternate Function Registers (PxALT, PyALT and PzALT)
These registers control the use of each of the Px, Py and Pz pins, respectively, as GPIO ports or as alternate functions.
When cleared (0), each bit in PxALT, PyALT or PzALT enables the corresponding pin as a GPIO signal.
When set (1), each bit enables the corresponding pin as an alternate function.
These registers are cleared (0) on reset, except when otherwise noted in Appendix A on page 408.
Location: See Appendix A
Type: R/W
Mnemonic Register Name Type
PxALT Port Px Alternate Function R/W
PyALT Port Py Alternate Function R/W
PzALT Port Pz Alternate Function R/W
PxDIR Port Px Direction R/W
PwDIR Port Pw Direction R/W
PxDOUT Port Px Data Output R/W
PzDOUT Port Pz Data Output R/W
PwDOUT Port Pw Data Output R/W
PxDIN Port Px Data Input RO
PyDIN Port Py Data Input RO
PwDIN Port Pw Data Input RO
PxWPU Px Weak Pull-Up R/W
PyWPU Py Weak Pull-Up R/W
Bit 76543210
Name Px Pins Alternate Function Enable
Reset 00000000
Bit 76543210
Name Py Pins Alternate Function Enable
Reset 00000000
Bit 76543210
Name Pz Pins Alternate Function Enable
Reset 00000000
Embedded Controller Modules (Continued)
www.national.com 120 Revision1.07
PC87591E/S/L
Port Direction Registers (PxDIR and PwDIR)
These registers configure the direction of the Px and Pw pins.
When cleared (0), each bit in PxDIR or PwDIR defines the corresponding pin as input.
When set (1), each pin is defined as output.
PxDIR and PwDIR are cleared (0) on reset except when otherwise noted in Appendix A. Clearing these registers configures
all the pins in port Px and Pw as input. Some specific reset values differ, as described in Appendix A on page 408.
Location: See Appendix A
Type: R/W
Port Data Output Register (PxDOUT, PzDOUT and PwDOUT)
Writing to PxDOUT, PzDOUT or PwDOUT registers sets the values of the output pins in ports Px, Pz and Pw, respectively.
Reading from one of these registers returns the last value written to the register.
Location: See Appendix A
Type: R/W
Port Data Input Registers (PxDIN, PyDIN and PwDIN)
Reading from PxDIN, PyDIN or PwDIN returns the current value of the pins in port Px, Py and Pw, respectively.
Location: See Appendix A
Type: RO
Bit 76543210
Name Px Port Direction
Reset 00000000
Bit 76543210
Name Pw Port Direction
Reset 00000000
Bit 76543210
Name Px Port Output Data
Bit 76543210
Name Pz Port Output Data
Bit 76543210
Name Pw Port Output Data
Bit 76543210
Name Px Port Input Data
Bit 76543210
Name Py Port Input Data
Bit 76543210
Name Pw Port Input Data
Reset
Embedded Controller Modules (Continued)
Revision 1.07 121 www.national.com
PC87591E/S/L
Port Weak Pull-Up Registers (PxWPU, PyWPU)
These registers control the pull-up for the related pin, when it used either as GPIO or in its alternate function. The pull-up is
enabled when the corresponding bit of PxWPU or PyWPU is set and the port buffer is in TRI-STATE. Otherwise, the pull-up
is disabled (i.e., high impedance).
On reset, PxWPU or PyWPU is cleared (0), disabling all pull-ups.
Location: See Appendix A
Type: R/W
Bit 76543210
Name Px Port Weak Pull-Up Enable
Reset 00000000
Bit 76543210
Name Py Port Weak Pull-Up Enable
Reset 00000000
Embedded Controller Modules (Continued)
www.national.com 122 Revision1.07
PC87591E/S/L
4.6 PS/2 INTERFACE
The PS/2 protocol is an industry-standard, PC-AT-compatible interface for keyboards. It uses a two-wire bidirectional TTL
interface for data transmission. Several vendors also supply PS/2 mouse products and other pointing devices that employ
the same type of interface.
The PC87591x provides four PS/2 data transfer channels. Each channel has two quasi-bidirectional signals that serve as
direct interfaces to an external keyboard, mouse or any other PS/2-compatible pointing device. Since the four channels are
identical, the connector ports are interchangeable.
4.6.1 Features
Four PS/2 channels
Enable/Disable for each of the four channels
Automatic hardware shift mechanism
Hardware support for PS/2 auxiliary device protocol
Processor interrupts at the beginning and end of data transfer
Optional software-based PS/2 implementation
4.6.2 General Description
In the previous generation of keyboard controllers, firmware executed the PS/2 device interface by toggling the interface
signals. The PC87591x (and its predecessor, the PC87570) supports this bit toggling mode via either polling or interrupt-
driven clock edge detection.
PS/2 devices’ firmware is significantly simplified through the use of a hardware accelerator mechanism. The accelerator in-
cludes an 8-bit shift register, a state-machine and control logic that handle both the incoming and outgoing data. It reduces
code overhead, performance requirements and reduces the overall interrupt latency from the core firmware. The hardware
is designed to meet the PS/2 device interface as defined in Keyboard and Auxiliary Device Controller (Types 1 and 2),
August 1988.
Section Naming conventions
In this section, the term “channel” describes the interface to one of the PS/2 devices and its two associated signals
(clock and data).
The term “shift mechanism” refers to the hardware accelerator.
The term “PS/2 interface” refers to the entire mechanism.
Interface Signals
The PS/2 interface includes eight external signals (PSCLK4-1 and PSDAT4-1) and six registers.
Module Block Diagram
A schematic description of the PS/2 interface appears in Figure 38. The interface to the three channels is symmetric and
only channel 1 is detailed in the figure.
Embedded Controller Modules (Continued)
Revision 1.07 123 www.national.com
PC87591E/S/L
Quasi-Bidirectional Drivers
The quasi-bidirectional drivers have an open-drain output (Q2), an internal pull-up (Q3) and a low-impedance pull-up(Q1).
Q2 pulls the signal low whenever the output buffer data is “0”. The weak pull-up (Q3) is active whenever the output buffer
data is “1” and WPUEN in PSCON register is set (1). The low impedance pull-up is active whenever the PC87591x changes
the output data buffer from “0” to “1”, thereby reducing the low-to-high transition time. The length of time that the low-imped-
ance pull-up is active is determined by HDRV field in PSCON register. A schematic description of this output driver appears
in Figure 39.
Interrupt Signals
The firmware can use an interrupt-driven scheme to implement the PS/2 device interface. When the shift mechanism is not
in use, four interrupts are available (PSINT4-1), one for each channel. (PSINT4 is not connected to the ICU as a separate
input, the MIWU PSCLK4 input should be used instead). When the shift mechanism is in use, only one interrupt signal is
used (PSINT1). More details on the use of the interrupts are provided in Section 4.6.4 on page 125. Figure 40 illustrates the
interrupt scheme with the associated enable bits.
Channel 4
Channel 3
Channel 1
Channel 2
Shift Mechanism
EN1
PSCLK1
PSDAT1
DATO1
DATI1 CLKO1
CLKI1
EN2 DATO2
DATI2 CLKO2
CLKI2
EN3 DATO3
DATI3 CLKO3
CLKI3
CLK1
WDAT1
RCLK1
RDAT1
ENSM
PS/2 I/F
Registers
Figure 38. PS/2 Interface Functional Diagram
EN4 DATO4
DATI4 CLKO4
CLKI4
+VCC
Q1
Q2
Q3
Rising Edge
Detector
Output Buffer Data
Input Buffer Data
Figure 39. Quasi-Bidirectional Buffer
WPUEN
Embedded Controller Modules (Continued)
www.national.com 124 Revision1.07
PC87591E/S/L
Power Modes
The PS/2 interface is active only when the PC87591x is in Active mode. The shift mechanism should be disabled before
entering Idle mode. In Idle mode, the state of output signals cannot be changed (i.e., the firmware cannot write to PSOSIG
register, and the shift mechanism does not function).
When the PC87591x needs to wake up on a Start bit detection by the MIWU, the PS/2 channels that may serve as wake-up
event sources must be enabled before entering Idle mode. To enable them, set to 1 their corresponding CLK bits in PSOSIG
register.
The MIWU module can be used to identify a start bit in Idle mode and to return the PC87591x to Active mode. The MIWU
receives PSCLK4-1 and PSDAT4-1 signals as inputs (see Table 17 on page 105). The MIWU should be programed to iden-
tify a falling edge on the clock or data lines of the enabled channels. In this configuration, a start bit causes the PC87591x
to switch from Idle mode to Active mode. Once Active mode is reached, the firmware should cancel the transaction just start-
ed and then enable re-transmission of the information by the device.
PS/2 Interface Operation
The PS/2 interface has two basic operating methods: with the shift mechanism disabled and with the shift mechanism en-
abled. The following sections describe how to use the PS/2 interface with each of these operating methods.
4.6.3 Operating With the Shift Mechanism Disabled
The shift mechanism is disabled when EN bit in PSCON register is cleared (0). In this state, the PS/2 clock and data signals
are controlled by the firmware, which performs the PS/2 protocol by manipulating the PS/2 clock and data signals.
Clock Signal Control
CLK4-1 bits in PSOSIG register control the value of the respective clock signals (PSCLK4-1). When one of these bits is
cleared (0), the relevant pin is held low. When set (1), the open-drain output is open and the respective clock signal is either
floating or held high by the pull-up. In this case, an external device can force the respective clock signal low.
When reading PSISIG register, bits RCLK4-1 indicate the current state of the corresponding clock signal.
Data Signal Control
WDAT4-1 bits in PSOSIG register control the value of the respective data signals (PSDAT4-1). When one of these bits is
cleared (0), the relevant data signal is held low. When set (1), the open-drain output is open and the respective data signal
is held high by the pull-up. In this case, an external device can force the respective data signal low.
When reading PSISIG register, bits RDAT4-1 indicate the current state of the corresponding data signal.
Interrupt Generation
When DSMIE bit in PSIEN register is set (1), the clock input signals are connected to the Interrupt Control Unit (ICU) for an
interrupt driven PS/2 protocol. The four interrupts that are generated are PSINT4-1 for channels 4-1, respectively.
The ICU should be programed to detect a falling edge on each of the clock signals. Disabling a channel by writing 0 to the
clock control signals (CLK4-1) may cause a falling edge on a clock signal. When such an interrupt is not desired, clear the
clock control bit (0); then clear the respective pending bit in the ICU (or in the MIWU, for PSINT4). This should be done while
interrupts are disabled. For more details about the ICU, see Section 4.3 on page 98.
EOT bit (PSTAT)
SOT bit (PSTAT)
PSCLK1
PSCLK3
PSCLK2
EOTIE bit (PSIEN)
SOTIE bit (PSIEN) PSINT1
PSINT2
PSINT3
Figure 40. PS/2 Interface Interrupt Signals
PSCLK4
DSMIE bit (PSIEN) PSINT4*
* Use PSCLK4 in the MIWU.
Embedded Controller Modules (Continued)
Revision 1.07 125 www.national.com
PC87591E/S/L
4.6.4 Operating With the Shift Mechanism Enabled
The shift mechanism is designed to off load the bit level handling of the data transfer from the firmware to a hardware
scheme; this improves system tolerance to interrupt latency. The mechanism includes a shift register and a state machine
that controls the PS/2 protocol.
Figure 41 illustrates the shift mechanism PS/2 data transfer sequence. There are three basic modes: Disabled, Receive and
Transmit. Different states in each mode define the progress of the data transfer. The rest of this section details the use of
the shift mechanism for implementing a PS/2 data transfer.
Reset the Shift Mechanism
Clearing either the shift mechanism enable bit (EN = 0 in PSCON register) or all the channels’ clock bits (CLK4-1 = 0) resets
the shift mechanism. In this state, PSTAT register is cleared (0016), and the state of the PS/2 clock and data signals
(PSCLK4-1 and PSDAT4-1) is set according to the value of their control bits (CLK4-1 and WDAT4-1, respectively).
When the shift mechanism is reset while in an unknown state or while in Transmit Idle state, the firmware should set (1)
WDAT4-1 before the shift mechanism is reset.
Before disabling the shift mechanism, the software should clear (0) CLK4-1 to prevent glitches on the clock signals.
Enable the Shift Mechanism
To enable the shift mechanism, verify that PSOSIG register is set to 4716 and then set (1) EN bit in PSCON register. This
puts the shift register state machine in Receive Inactive or Transmit Inactive state (XMT is 0 or 1, respectively, in PSCON
register). In either of these states, the clock signals (PSCLK4-1) are low and the data signals PSDAT4-1 are either floating
or pulled high.
PS/2 Reset
XMT = 0
XMT = 1
Start Bit
Detected
XMT = 1
EN = 1 and
EN = 0
Disabled
Receive
Inactive
XMT = 0
EN = 1 and
Transmit
Idle
Transmit
Active
Line Control
Bit Detected
End of
Transmission
or CLK4 = 1
Start Bit
Detected
Receive
Idle
CLK1, CLK2, CLK3
Receive
Active
Stop Bit
Detected
End of
Reception
and/or CLK4 = 1
Transmit Mode Receive Mode
EN = 0
CLK1, CLK2, CLK3
and CLK4 = 0
CLK1, CLK2, CLK3
and CLK4 = 0
Transmit
Inactive
Figure 41. Shift Mechanism State Diagram
CLK1, CLK2, CLK3
Embedded Controller Modules (Continued)
www.national.com 126 Revision1.07
PC87591E/S/L
Shift Status
The PSTAT register indicates the current status of the shift mechanism. The data transfer process may be in one of the
following three states:
Shifter Empty:
The shift mechanism is in Receive Inactive, Receive Idle, Transmit Inactive or Transmit Idle state. The PSTAT is
cleared because none of the enabled devices has sent a start bit.
Start Bit Detected:
The shift mechanism is in Receive Active or Transmit Active state. This indicates that a start bit was identified for at
least one of the channels and the shift process has begun. SOT bit in PSTAT register indicates the detection of the
start bit and ACH field in PSTAT register indicates the active channel (the channel on which the start bit was detect-
ed).
End of Transaction:
The shift mechanism is in End-of-Reception or End-of-Transmission state. This indicates that the last bit of the trans-
fer sequence was detected (and the data can therefore be read from PSDAT register) or that the data transmission
was completed (for receive and transmit, respectively). EOT bit in PSTAT register indicates transfer completion. If a
parity error was detected in the received data, PERR bit in PSTAT register is set. If a stop bit was detected low in-
stead of high, RFERR bit in PSTAT register is set.
Input Signal Debounce
The PC87591x performs a debounce operation on the clock input signal before determining its logical value. IDB field in
PSCON register determines for how many clock cycles the input signal must be stable to define a change in its value.
Interrupt Generation
The PSINT1 is an interrupt signal generated by the shift mechanism to allow an interrupt driven interface with the firmware.
The ICU should be programed to detect high-level interrupts on the PSINT1 interrupt. See Section 4.3 on page 98 for details
on the ICU. SOTIE and EOTIE bits in PSIEN register mask the interrupt signaling for SOT and EOT bits, respectively, in
PSTAT register.
Receive Mode
Receive Inactive
When the shift mechanism is enabled and bit XMT=0 in PSCON register, the shift mechanism enters Receive mode in the
Receive Inactive state. Receive Idle state is entered when one (or more) of the channels is enabled, by setting the channel
enable bit (CLK4-1 for channels 4-1, respectively). In this state, the shift-mechanism sets the clock and data lines of the
enabled channels high (1) and waits for a start bit.
Receive Idle
In the Receive Idle state, the PS/2 interface waits for input from any one of the enabled channels. The first of the enabled
channels to send a start bit is selected for handling by the shift mechanism. The other two channels are disabled by forcing
“0” on their clock lines.
Start Bit Detection
The start bit is identified by a falling edge on the clock signal while the data signal is low (0).
If the start bit is identified simultaneously in more than one channel, one channel is selected for receive, while the other chan-
nel’s transfer is aborted. The channel with the lower number is selected (i.e., channel 1 has priority over channels 2, 3 and
4, channel 2 has priority over channel 3 and 4 and channel 3 has priority over channel 4). The data transfer in the other
channels is aborted before 10 data bits have been sent (by forcing the clock signal to 0), and the transmitting PS/2 device
resends its data when its interface is enabled again by the firmware. This mechanism ensures that no incoming data is lost.
When the hardware sets (1) SOT bit and designates the selected channel in ACH field, this indicates receipt of the start bit
in PSTAT register. In addition, if SOTIE is set in PSIEN register, an interrupt signal to the ICU is set high. The firmware may
use this interrupt to start a time-out timer for the data transfer.
Receive Active
After identifying the start bit, the shift mechanism enters the “Receive-Active” state. In this state the clock signal of the se-
lected device (PSCLK1, PSCLK2, PSCLK3 or PSCLK4) sets the data bit rate. On each falling edge of the clock, new data
is sampled on the data signal of the active channel (i.e., PSDAT1 PSDAT2, PSDAT3 or PSDAT4).
Following the start bit, eight bits of data are received (clocks 2 through 9); a parity bit follows (10th clock) and then a stop bit
(11th clock). The stop bit is indicated by a falling edge of the clock with the data signal high (1). If the 11th clock is identified
with data low, the receive frame error bit (RFERR in PSTAT register) is set but the clock is treated as the stop bit.
After the parity is received, the shift mechanism checks the incoming data for parity errors. If there are eight data bits with a
value of 1 and the parity bit is even, PERR bit in PSCON register is set, indicating a parity error.
Embedded Controller Modules (Continued)
Revision 1.07 127 www.national.com
PC87591E/S/L
End of Receive
When the stop-bit is detected, the shift mechanism enters the “End-Of-Reception” state. In this state, the shift mechanism:
Disables all the clock signals by forcing them low
Sets End-Of-Transaction status bit (EOT = 1 in PSTAT register)
If EOTIE bit in PSTAT register is set, it asserts (1) the interrupt signal to the ICU.
The shift mechanism stays in this state until it is reset.
Figure 42 illustrates the receive byte sequence, as defined by the PS/2 standard.
Transmit Mode
Transmit Inactive
When the shift mechanism is enabled and XMT bit in PSCON register is set (1):
The shift mechanism enters Transmit mode in Transmit Inactive state with all clock signals low and data signals high
(PSOSIG = 4716).
The firmware writes the data to be transmitted to the PS/2 data register (PSDAT).
The data line of the channel to be transmitted is forced low by the firmware clearing its data bit (WDAT4-1 for chan-
nels 4-1, respectively).
Transmit Idle
The Transmit Idle state can be entered by setting the channel enable bit (CLK4-1 for channel 4-1, respectively). This enables
the channel to be used for transmission. In this state, the shift-mechanism sets the clock of the enabled channel high (1)
while the data line of that channel is held low and waits for a start bit. When a PS/2 device senses the clock signal high with
the data signal low, it identifies a transmit request from the PC87591x.
The three channels not in use are disabled by forcing “0” on their clock lines.
Start Bit Detection
The start bit is identified by a falling edge on the clock signal while the data signal is low (0).
When a start bit is detected, data transmission begins by outputting bit 0 (LSB) of the transmitted data and setting data bits
WDAT4-1 in PSOSIG register. This allows bit 0 of the transmitted data to be output on the PS/2 data signal (PSDAT1,
PSDAT2, PSDAT3 or PSDAT4, according to the active channel).
In addition, the hardware sets the SOT bit (to 1) and stores the active channel number in ACH field, indicating transmission
of the start bit in PSTAT register. Note that if SOTIE bit in PSIEN register is set, an interrupt signal to the ICU is set high.
The firmware can use this interrupt to start a time-out timer for the data transfer.
Transmit Active
After identifying the start bit, the shift mechanism enters the Transmit Active state. The clock signal of the selected device
(PSCLK1, PSCLK2, PSCLK3 or PSCLK4) sets the data bit rate.
CLK
DATA Bit 0 Parity Bit Stop BitStart Bit
1st
CLK 2nd
CLK 10th
CLK 11th
CLK
Figure 42. PS/2 Receive Data Byte Timing
Embedded Controller Modules (Continued)
www.national.com 128 Revision1.07
PC87591E/S/L
After each of the next seven falling edges of the clock line, one more data bit (bits 1 through 7) is driven on the data line of
the active channel (either PSDAT1, PSDAT2, PSDAT3 or PSDAT4).
On the ninth falling edge of the clock, the parity bit is output. The parity bit is high (1) if the number of bits with a value of 1
in the transmitted data was even (i.e., odd parity).
The tenth falling edge causes a 1 to be output as a stop bit. The data signal remains high to allow the PS/2 device to send
the line control bit.
The auxiliary device then completes the transfer by sending the line-control bit. The line-control bit, is identified by the data
signal being low after the 11th falling edge of the clock.
End of Transmission
The End-Of-Transmission state is entered when the line-control bit is detected. In response, the shift mechanism holds all
clock signals low, and if the internal pull-up is enabled, all data signals are pulled high by the internal pull-up.
The End-Of-Transaction flag (EOT in PSTAT register) is set to indicate that the transmit operation was completed; in addi-
tion, if EOTIE bit in PSIEN register is set, the interrupt signal to the ICU is set high.
The shift mechanism stays at this state until being reset.
Figure 43 illustrates the transmit byte sequence, as defined by the PS/2 standard.
Transfer Abort
At each stage of a receive or transmit operation, the transaction can be aborted by clearing all four channel enable bits
(CLK4-1) in PS/2 Output Signal register (PSOSIG) to 0. This resets the shifter state machine and puts it in the Enabled In-
active state. If the shift mechanism is in Transmit Inactive or Transmit Idle state, WDAT4-1 bits should also be set.
4.6.5 PS/2 Interface Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
CLK
DATA Bit 0 Parity Bit Stop BitStart Bit
1st
CLK 2nd
CLK 9th
CLK 11th
CLK
I/O
Inhibit 10th
CLK
Figure 43. PS/2 Transmit Data Byte Timing
Embedded Controller Modules (Continued)
Revision 1.07 129 www.national.com
PC87591E/S/L
PS/2 Register Map
PS/2 Data Register (PSDAT)
The PSDAT register is a byte-wide read/write register. In Receive mode, PSDAT holds the data received in the last message
from the PS/2 device. In Transmit mode, the data to be shifted out is written to this register. When the PS/2 i/f is reset, the
contents of this register become invalid.
On reset, the PS/2 interface is set to Receive mode. In this mode, PSDAT should be read only when EOT bit in PSTAT
register is set to 1.
Setting the transmit enable bit in PSCON register to 1 (XMT = 1 in PSCON register) puts the PS/2 interface in Transmit
mode. PSDAT should be written only when in Transmit mode and when all four channel enable bits CLK4-1 in PSOSIG reg-
ister are cleared (0).
Location: 00 FE8016
Type: R/W
PS/2 Status Register (PSTAT)
The PSTAT register is a byte-wide read-only register. It contains the status information on the data transfer on the PS/2
ports. All non-reserved bits of PSTAT are cleared (0) on reset when CLK1, CLK2 and CLK3 in PSOSIG are cleared and
when EN bit in PSCON register is cleared. Reading PSTAT does not clear any of its bits.
Location: 00 FE8216
Type: RO
Mnemonic Register Name Type
PSDAT PS/2 Data Register R/W
PSTAT PS/2 Status Register RO
PSCON PS/2 Control Register R/W
PSOSIG PS/2 Output Signal Register R/W
PSISIG PS/2 Input Signal Register RO
PSIEN PS/2 Interrupt Enable Register R/W
Bit 76543210
Name Data
Bit Description
7-0 Data. Contains the data received in the last message (or that is transmitted in the following transmission). Bit 0
is the first bit to be shifted (LSB).
Bit 76543210
Name Reserved RFERR ACH PERR EOT SOT
Reset x 0000000
Bit Description
0SOT (Start of Transaction). When set to 1, indicates that a start bit was detected. The ACH field (bits 5-3 of
this register) indicates which of the channels it was detected on.
1EOT (End of Transaction). When set to 1, Indicates that a PS/2 data transfer was completed, i.e., a stop bit
was detected at Receive mode or a line control bit was detected at Transmit mode.
2PERR (Parity Error).
When set to 1, indicates that a parity error was detected in the last data transfer.
Embedded Controller Modules (Continued)
www.national.com 130 Revision1.07
PC87591E/S/L
PS/2 Control Register (PSCON)
ThePSCONregister is an 8-bit read/write register. It controls the operation of the PS/2 interface by enabling it and controlling
the data transfer direction. On reset, PSCON is set to 0016.
Location: 00 FE8416
Type: R/W
5-3 ACH (Active Channel). Defines which of the PS/2 channels is currently active (i.e., a start bit was detected). In
case more than one channel become active simultaneously, only the one with the highest priority (lowest
number) is flagged.
Bits
5 4 3 Description
0 0 0: None of the channels is active
0 0 1: Channel 1
0 1 0: Channel 2
1 0 0: Channel 3
1 0 1: Channel 4
6RFERR (Receive Frame Error).
When set to 1, indicates that the stop bit in a received frame was detected low instead of high.
7Reserved.
Bit 76543210
Name WPUEN IDB HDRV XMT EN
Reset 00000000
Bit Description
0EN (Shift Mechanism Enable).
0: The hardware shift mechanism is disabled and the software controls and monitors the PS/2 signals using
PSOSIG and PSISIG registers.
1: The hardware shift mechanism is enabled. The enabled channels are controlled by PSOSIG, and Transmit/Re-
ceive mode is controlled by the XMT bit.
1XMT (Transmit Enable).
0: Receive mode.
1: Causes the PS/2 interface to enter Transmit mode.
3-2 HDRV (High Drive). Defines the quasi-bidirectional buffers’ behavior on transition from low to high. HDRV
defines the period of time for which the output is pulled high with a low-impedance drive (when the PC87591x
changes the output level from low to high). This period is a function of the PC87591x clock as follows:
Bits
3 2 Description
0 0: Disabled
0 1: Low-impedance drive for one clock cycle
1 0: Low-impedance drive for two clock cycles
1 1: Low-impedance drive for three clock cycles
Bit Description
Embedded Controller Modules (Continued)
Revision 1.07 131 www.national.com
PC87591E/S/L
PS/2 Output Signal Register (PSOSIG)
The PSOSIG register is a byte-wide, read/write register. It allows setting the value of the PS/2 port signals. When the shift
mechanism is enabled, the clock control bits in this register define the active channel(s). On reset, this register is set to 4716.
Location: 00 FE8616
Type: R/W
6-4 IDB (Input Debounce). Defines the number of PC87591x clock cycles during which the clock input is expected
to be stable before the shift mechanism identifies its new value. This protects the shift mechanism from false
edge detections. The number of PC87591x clock cycles for which the input should be stable before an edge is
detected is as follows:
Bits
6 5 4 Description
0 0 0: One cycle
0 0 1: Two cycles
0 1 0: Four cycles
0 1 1: Eight cycles
1 0 0: 16 cycles
1 0 1: 32 cycles
7WPUEN (Weak Pull-Up Enable).
0: The pull-up is disabled. In this state, the system must ensure that PS/2 interface signals are not floating, to en-
able proper PS/2 operation.
1: Enables the internal pull-up of the output buffer. The pull-up remains active as long as the buffer does not drive
the signal to low level.
Bit 76543210
Name CLK4 WDAT4 CLK3 CLK2 CLK1 WDAT3 WDAT2 WDAT1
Reset 01000111
Bit Description
0WDAT1 (Write Data Signal Channel 1). Controls the data output to channel 1 data signal (PSDAT1). Use of
this bit depends on whether or not the shift mechanism is enabled.
When the shift mechanism is disabled (EN bit in PSCON register is set to 0), the data in WDAT1 is output to
PSDAT1 signal.
If WDAT1 is cleared (0), the output buffer data is 0 (i.e., PSDAT1 is forced low).
If WDAT1 is set (1), the output buffer data is 1 (i.e., PSDAT1 is pulled high by the internal pull-up and may
be pulled low by an external device).
When the shift mechanism is enabled (EN=1), WDAT1 should be set to 1, except when the shift mechanism is
in Transmit mode. In this case, when in transmit-inactive and it is intended to transmit data to channel 1, the
firmware should clear WDAT1 bit to force the transmit signaling (low) to the PS/2 device.
Note: WDAT1 is set by the hardware after the PC87591x detected a start bit (i.e., on entering Transmit Active
state). If a transmission is aborted before Transmit Active state, WDAT1 should be set (1) prior to disabling
the channel.
1WDAT2 (Write Data Signal Channel 2). Controls the data output to channel 2 data signal (PSDAT2). For more
information, see the description of bit 1 (above).
2WDAT3 (Write Data Signal Channel 3). Controls the data output to channel 3 data signal (PSDAT3). For more
information, see the description of bit 1 (above).
Bit Description
Embedded Controller Modules (Continued)
www.national.com 132 Revision1.07
PC87591E/S/L
Note: When CLK1, CLK2, CLK3 and CLK4 are all 0, this is interpreted as a shift mechanism reset. In this case, the PSTAT
register and the shift state machine are reset to their initial state.
PS/2 Input Signal Register (PSISIG)
The PSISIG register is an 8-bit read only register. It provides the current value of the PS/2 port signals.
Location: 00 FE8816
Type: RO
3CLK1 (Enable Channel 1)
0: Forces the PSCLK1 pin low (0) and disables channel 0 of the shift mechanism.
1: Depends on whether or not the shift mechanism is enabled.
When the shift mechanism is enabled (EN bit in PSCON register is set to 1), channel 1 of the PS/2 ports
is enabled.
When the shift mechanism is disabled (EN bit in PSCON register is set to 0), the clock line output buffer
data is 1 (i.e., the signal is pulled high by the pull-up, if enabled, and may be pulled low by an external de-
vice).
4CLK2 (Enable Channel 2). Same as bit 3 of this register (described above) but for channel 2.
5CLK3 (Enable Channel 3). Same as bit 3 of this register (described above) but for channel 3.
6WDAT4 (Write Data Signal Channel 4). Controls the data output to channel 4 data signal (PSDAT4). For more
information, see the description of bit 1 (above).
7CLK4 (Enable Channel 4). Same as bit 3 of this register (described above) but for channel 4.
Bit 76543210
Name RCLK4 RDAT4 RCLK3 RCLK2 RCLK1 RDAT3 RDAT2 RDAT1
Bit Description
0RDAT1 (Read Data Signal Channel 1). The current value of the channel 1 data signal (PSDAT1).
1RDAT2 (Read Data Signal Channel 2). The current value of the channel 2 data signal (PSDAT2).
2RDAT3 (Read Data Signal Channel 3). The current value of the channel 3 data signal (PSDAT3).
3RCLK1 (Read Clock Signal Channel 1). When read, returns the current value of the channel 1 clock signal
(PSCLK1).
4RCLK2 (Read Clock Signal Channel 2). When read, returns the current value of the channel 2 clock signal
(PSCLK2).
5RCLK3 (Read Clock Signal Channel 3). When read, returns the current value of the channel 3 clock signal
(PSCLK3).
6RDAT4 (Read Data Signal Channel 4). The current value of the channel 4 data signal (PSDAT4).
7RCLK4 (Read Clock Signal Channel 4). When read, returns the current value of the channel 4 clock signal
(PSCLK4).
Bit Description
Embedded Controller Modules (Continued)
Revision 1.07 133 www.national.com
PC87591E/S/L
PS/2 Interrupt Enable Register (PSIEN)
The PSIEN register is an 8-bit read/write register. It enables/disables the various interrupts generated by the PS/2 module.
Bits in PSIEN register may be cleared to 0 only when interrupts are disabled (i.e., in the core, I or E bits in PSR register are
0) or when the corresponding interrupts in the ICU are masked. Bits in PSIEN register may be set to 1 at any time. On reset,
non-reserved bits of PSIEN are cleared.
Location: 00 FE8A16
Type: R/W
Bit 76543210
Name Reserved DSMIE EOTIE SOTIE
Reset 00000000
Bit Description
0SOTIE (Start of Transaction Interrupt Enable). Used for enabling the interrupt generation on a transaction
start detection.
0: SOT bit in PSTAT register does not affect the interrupt signal.
1: The interrupt signal (PSINT1) to the ICU is active (1) whenever SOT bit in PSTAT register is set.
Note: Once set, SOT is not cleared until the shift mechanism is reset. Therefore SOTIE should be cleared on
the first occurrence of an SOT interrupt. SOTIE should be set (1) when the PS/2 module is programed to
handle the impending transfer.
1EOTIE (End of Transaction Interrupt Enable). Used for enabling the interrupt generation on an End of
Transaction detection.
0: EOT bit in PSTAT register does not affect the interrupt signal.
1: The interrupt signal (PSINT1) to the ICU is active (1) whenever EOT bit in PSTAT register is set.
Note: Once set, EOT is not cleared until the shift mechanism is reset. Therefore EOTIE should be cleared on
the first occurrence of an EOT interrupt. EOTIE should be set (1) when the PS/2 module is programed to
handle the impending transfer.
2Disabled Shift Mechanism Interrupt Enable (DSMIE). Used for enabling the interrupt generation when the
shift mechanism is disabled.
0: The four interrupt signals are low. Note that PSINT1 may be activated (1) by other interrupt sources ofthe module.
1: The clock input signals are connected to the Interrupt Control Unit (ICU), to allow implementing an interrupt driv-
en PS/2 protocol. The four interrupts generated are PSINT1, PSINT2, PSINT3 and PSINT4, for channels 1, 2,
3 and 4, respectively. Note that PSINT4 is connected to the MIWU and not directly to the ICU.
Note: When the shift mechanism is disabled, no debounce is applied to the PSCLK inputs before producing the
interrupt signals, except for local synchronization.
7-3 Reserved.
Embedded Controller Modules (Continued)
www.national.com 134 Revision1.07
PC87591E/S/L
4.7 MULTI-FUNCTION 16-BIT TIMER (MFT16)
The PC87591x includes two Multi-Function Timer (MFT) modules. The registers of each module are prefixed with Tn and
the signals are suffixed with an n (where n is the module’s number, i.e., 1 or 2). Each MFT16 module consists of two func-
tional units designed to satisfy a wide range of application requirements. The units include:
Clock Source Unit that contains a pre-scaler with one clock source selector for each counter.
Main timer/counter and action unit that contains two counters, two reload registers for PWM, Input Capture or
Counter modes.
Mode selector/control unit that defines the function of the I/O pins and the interrupts.
Figure 44 shows the contents of an MFT16 and the top-level interaction. The rest of the section describes an MFT16 module.
4.7.1 Features
Two 16-bit programmable timers/counters
Two 16-bit reload/capture registers. These registers are used either as reload registers or capture registers, depend-
ing on the mode of operation.
A 5-bit fully programmable clock pre-scaler
Clock source selectors for each counter. These enable each counter to operate in:
Pulse accumulate mode
External event mode
Prescaled system clock mode
Slow speed clock input mode (where applicable)
Two I/O pins (TAn and TBn), with programmable edge detection; these operate as:
Capture inputs
Capture and preset inputs
External event (clock) inputs
PWM outputs
Two interrupts, one for each counter, that can be generated/ triggered by:
Timer underflow
Timer reload
Input capture
Four pending bits, which can be polled by software, are associated with the two interrupts.
Reload/Capture A
Counter 1
Reload/Capture
Timer/Counter Timer/Counter and Action
Clock
System
Clock
TBn
Toggle/Capture/Interrupt
& Control
PWM/Capture/Counter Mode Select
TAn
External Event
Interrupt A
Interrupt B
Slow
Clock
Figure 44. MFT16 Functional Diagram
32.768 KHz
Source
and
TnCRA
Timer/Counter 1
TnCNT1
Reload/Capture B
TnCRB
Timer/Counter 2
TnCNT2
Clock
Counter 2
Clock
Pre-Scaler
Embedded Controller Modules (Continued)
Revision 1.07 135 www.national.com
PC87591E/S/L
4.7.2 Clock Source Unit
The clock source unit, as shown in Figure 45, contains two clock selectors for each counter and a 5-bit clock pre-scaler.
Pre-Scaler
The 5-bit clock pre-scaler consists of a pre-scaler register and a 5-bit counter, allowing the timer to run with a prescaled
clock. The system clock is divided by the value contained in TnPRSC+1. The minimum counter clock frequency is thus the
system clock divided by 32, and the maximum counter clock frequency is equal to the system clock. The pre-scaler register,
TnPRSC, can be read or written by software at any time. The pre-scaler counter is a 5-bit down counter which can not be
read or written by software. The 5-bit counter and the pre-scaler register TnPRSC are cleared on reset
External Event Clock
The TBn I/O pin can be selected as an external event input clock source for either of the two 16-bit counters. The polarity of
the input signal is programmable to trigger a count if either a rising or a falling edge is detected on TBn. The minimum pulse
width of the external signal is one system clock cycle; thus the maximum frequency with which the counter can run in this
mode is limited to half the system clock frequency.
Note: An External Event clock is not available in Dual Channel Capture mode because this mode requires TBn as an input.
Pulse Accumulate Mode
In Pulse Accumulate mode, the counter can also be clocked while an external signal on TBn is either high or low. In this
configuration, the output of the pre-scaler is gated with an external signal applied on TBn input. This mode can be used to
obtain a cumulative count of pre-scaler output clock pulses, as shown in Figure 46.
Note: Pulse Accumulate mode is not a vailable in Dual Channel Capture mode because this mode requires TBn as an input.
Slow-Speed Clock
A slow-speed clock of 32.768 KHz can be used as a clock source for the two 16-bit counters. The MFT16 synchronizes the
slow-speedclockwiththesystemclock.Therefore,themaximum input frequency of the slow-speed clock is the system clock
rate divided by four.
Some power save modes stop the system clock completely. When this occurs, the timer stops counting the slow-speed clock
until the system clock resumes. While operating in a power-save mode that uses a slow system clock, the slow-speed clock
source for the timer can only be used if it is at least four times faster than the slow- speed clock for the counter.
Pre-Scaler Register
TPRSC
Pre-Scaler Counter
5-Bit
System
Clock
Reset
TBn
Pulse
Accumulate
External
Event
No Clock
Prescaled
Clock
Counter 1
Clock
Select
Counter 2
Clock
Select
Counter 1
Clock
Counter 2
Clock
Synchr.
Slow Speed
Clock
Synchr.
Figure 45. Clock Pre-Scaler and Selector
Embedded Controller Modules (Continued)
www.national.com 136 Revision1.07
PC87591E/S/L
Counter Clock Source Select
The clock source unit contains two clock source selectors that allow the clock source to be selected independently for each
of the two 16-bit counters from one of the following sources:
No clock, in which case the counter is stopped
Prescaled system clock
External Event count based on TBn
Pulse Accumulate mode based on TBn
Slow Speed Clock i.e., 32.768 KHz
4.7.3 Timer/Counter and Action Unit
The timer/counter and action unit consists of two 16-bit counters, TnCNT1 and TnCNT2, in addition to two 16-bit reload/cap-
ture registers, TnCRA and TnCRB. The timers are down counters capable of triggering events on underflow detection (count
from 000016 to FFFF16). In addition, it contains the mode control logic which allows the timer to operate in any of four oper-
ation modes described below.
Different interrupts can be triggered on certain conditions, and the functionality of the I/O pins changes depending on the
mode of operation. Therefore the interrupt control and the I/O control are an integral part of the timer/counter unit.
Operation Modes
The MFT16 can be configured to operate in any one of four modes, as summarized in Table 18 and described in this section.
Mode 1, PWM and Counter
PWM can be used to generate precise pulses of known width and duty cycle on the TAn pin. The timer is clocked by the
instruction clock. An underflow causes the timer register to be reloaded alternately from the TnCRA and TnCRB registers
and optionally causes TAn output to toggle. Thus, the values stored in TnCRA and TnCRB registers control the high and
low time of the signal produced on TAn. In PWM mode, timer/counter 2 can be used either as a simple system timer or as
an external event counter. The counter can be loaded by software with a specific value; the counter can then generate an
interrupt after the pre-programed number of external events have been received on TBn input.
Table 18. Operation Modes
Mode Description Timer/Counter 1
(TnCNT1) Reload/Capture A
(TnCRA) Reload/Capture B
(TnCRB) Timer/Counter 2
(TnCNT2)
1PWM and system
timer or external
event counter Counter for PWM Auto Reload A =
PWM time 1 Auto reload = PWM
time 2 System Timer or ex-
ternal event counter
2Dual input capture
and system timer Capture A and B
time base Capture counter 1
value on TAn event Capture counter 1
value on TBn event System Timer
3Dual independent
timer Time base for first
timer Reload register for
timer/counter 1 Reload register for
timer/counter 2 Time base for sec-
ond timer
4Input capture and
timer Time base for first
timer Reload register for
timer/counter 1 Capture counter 1
value on TBn event Capture B time base
TBn
Pre-Scaler Output
Counter Clock
Figure 46. Pulse Accumulate Mode
Embedded Controller Modules (Continued)
Revision 1.07 137 www.national.com
PC87591E/S/L
Figure 47 shows a block diagram of the timer operating in mode 1. In PWM mode, counter 1, TnCNT1, functions as the time
base for the PWM timer. Counter 1 counts down at the clock rate selected via the counter 1 clock selector. When an under-
flow occurs, the timer register is reloaded alternately from the TnCRA and TnCRB registers, and counting proceeds down-
ward from the loaded value. On reset, and every time this mode is entered, the first reload in this mode is from the TnCRA
register. Once enabled, the counter starts counting down from the value currently loaded to it. At the first underflow, the timer
is loaded from TnCRA; on the second underflow, it is loaded from TnCRB; on the third underflow, it is loaded from TnCRA,
and so on. Note that every time the counter is stopped through the selection of “No-Clock” in the counter 1 clock selector
(TnCKC), it obtains its first reload value after it has been re-started from TnCRA register.
The timer can be configured to toggle TAn output bit on underflow. This results in the generation of a clock signal on TAn,
with the width and duty cycle controlled by the values stored in TnCRA and TnCRB registers. This PWM clock is processor-
independent because once the timer is set up, no more interaction is required by software (and therefore the CPU) to gen-
erate a continuous PWM signal. Software can select the initial value of the PWM output signal as either high or low. See
“Timer I/O Functions” on page 141 for additional details. The timer can be configured to generate separate interrupts on re-
load from TnCRA and TnCRB. The interrupts can be enabled or disabled under software control. The TAnPND or TnBPND
flags, respectively, which are set by the hardware on occurrence of a timer reload, indicate which interrupt occurred. See
Section 4.7.4 on page 140 for detailed information.
In this mode of operation, timer/counter 2 can be used as a simple system timer, an external event counter or a pulse accu-
mulate counter. Counter TnCNT2 counts down with the clock selected via the counter 2 clock selector, and TnCNT2 can be
configured to generate an interrupt on underflow if the interrupt is enabled by TnDIEN bit. See Section 4.7.4 on page 140
for detailed information.
Mode 2, Dual Input Capture
Dual Input Capture mode can be used to precisely measure the frequency of an external clock that is slower than the se-
lected clock source frequency or to measure the elapsed time between external events. A transition received on the TAn or
TBn pin causes a transfer of timer/counter 1 contents to TnCRA or TnCRB register, respectively. In this mode, timer/counter
2 can be utilized as a system timer that is pre-loaded by software and generates an interrupt on underflow.
Figure 48 shows a block diagram of the timer operating in mode 2. In this mode of operation, the timebase of the capture
timer is formed by counter 1, which counts down with the clock selected via the counter 1 clock selector. In Dual Input Cap-
ture mode, TAn and TBn pins function as capture inputs. A transition received on TAn pin causes a transfer of the timer
contents to TnCRA register. Similarly, a transition received on the TBn pin causes a transfer of the timer contents to TnCRB
register. TAn and TBn inputs can be configured to perform a counter preset to FFFF16 on reception of a valid capture event.
Reload A = Time 1
Timer/Counter 1
Reload B = Time 2
Timer 1
Clock
Underflow
TAn
TAIEN
TAPND
TnCNT1
TnCRA
TnCRB
TBIEN
TBPND
Timer
Interrupt 1
Timer
Interrupt 1
TAEN
Timer/Counter 2
TnCNT2
Timer 2
Clock TDIEN
TDPND
Timer
Interrupt 2
TBn
Clock
Selector
Underflow
Figure 47. Mode 1, PWM and Counter
Embedded Controller Modules (Continued)
www.national.com 138 Revision1.07
PC87591E/S/L
In this case, the current value of the counter is transferred to the corresponding capture register; following this, the counter
is preset to FFFF16. Using this approach enables an external signal’s on-time, off-time or period to be directly determined,
while reducing CPU overhead.
The pulse width of the input signal on TAn and TBn must be equal to or greater than one system clock cycle (see
Section 7.6.10 on page 399 for additional details). The values captured in TnCRA register at different times reflect the
elapsed time between transitions on the TAn pin. The same is true for TnCRB register and the TBn pin. Each input pin can
be configured to sense either rising or falling edge transitions.
The timer can be configured to generate interrupts on reception of a transition on either TAn or TBn. The interrupts can be
enabled or disabled separately for TAn or TBn by TAnIEN and TnBIEN bits. An underflow of TnCNT1 can also generate an
interrupt if the interrupt was enabled by TnCIEN bit. All three interrupts have individual pending flags. See Section 4.7.4 on
page 140 for detailed information.
Timer/counter 2 can be used as a “simple” system timer in this mode of operation. The TnCNT2 counter counts down with
the clock selected via the counter 2 clock selector, and TnCNT2 can be configured to generate an interrupt on underflow if
the interrupt was enabled by TnDIEN bit. See Section 4.7.4 on page 140 for detailed information.
Note that TnCNT1 cannot operate in the “Pulse Accumulate” or “External Event Counter” modes of operation since TBn input
is used as a capture input. Selecting either “Pulse Accumulate” mode or “External Event Counter” mode for TnCNT1 causes
TnCNT1 to stop. However, all available clock source modes may be selected for TnCNT2. Thus it is possible to use TnCNT2
to determine the number of capture events on TBn or the elapsed time between capture events on TBn.
Mode 3, Dual Independent Timer
Dual Independent Timer mode can be used for a wide variety of system tasks such as the generation of periodic system
interrupts, based either on the prescaled clock or external events on TBn. The timer can also toggle TAn pin on underflow,
allowing the simple generation of a processor-independent 50% duty cycle PWM signal on TAn. In this mode, TnCNT1
counts down and reloads from TnCRA on underflow while TnCNT2 is reloaded from TnCRB on underflow.
In this mode, the timer is configured to operate as a dual independent system timer or dual external event counter. In addi-
tion, timer/counter 1 can generate a 50% duty cycle PWM signal on the TAn pin. The TBn pin can be used as an external
event input or pulse accumulate input and forms the clock source to either counter 1 or counter 2, as described above. Both
counters can also be operated using the prescaled system clock. Figure 49 shows a block diagram of the timer in mode 3.
Capture A
Timer/Counter 1
Capture B
TnCNT1
TnCRA
TnCRB
Timer/Counter 2
TnCNT2
Timer1
Clock
Timer 2
Clock
TBn
TAn
TAIEN
TAPND
Timer
Interrupt 1
TBIEN
TBPND
Timer
Interrupt 1
TCIEN
TCPND
Timer
Interrupt 1
Underflow
TDIEN
TDPND
Timer
Interrupt 2
Underflow
TAEN
Preset
Preset
TBEN
Figure 48. Mode 2, Dual Input Capture
Embedded Controller Modules (Continued)
Revision 1.07 139 www.national.com
PC87591E/S/L
Timer/counter 1 (TnCNT1) counts down at the rate of the selected clock (see “Counter Clock Source Select” on page 136
for additional details). On underflow, TnCNT1 is reloaded from TnCRA register and counting proceeds. If enabled, the TAn
pin toggles on underflow of TnCNT1. Software can select the initial value of TAn output as either high or low (see “Timer I/O
Functions” on page 141 for additional details). In addition, the TnAPND interrupt pending flag is set, and a timer interrupt 1
is generated if TnAIEN bit is set to 1 (see Section 4.7.4 on page 140 for detailed information). Since TAn toggles on every
underflow, a 50% duty cycle PWM signal can be generated on TAn without requiring interaction by the core.
Timer/counter 2 (TnCNT2) counts down at the rate of the selected clock (see “Counter Clock Source Select” on page 136
additional details). On every underflow of TnCNT2, the value contained in TnCRB register is loaded into TnCNT2, and count-
ing proceeds downwards from that value. In addition, the TnDPND interrupt pending flag is set, and a timer interrupt 2 is
generated if TnDIEN bit is set to 1. See Section 4.7.4 on page 140 for detailed information.
Mode 4, Input Capture and Timer
It is also possible to operate in a mode that offers a combination of a single timer, with automatic reload, and a single capture
timer. In this mode, TnCNT1 operates as a PWM-timer that is reloaded from TnCRA on underflow while TnCNT2 forms the
time base of the capture timer. The value on TnCNT2 is transferred to TnCRB when a valid event on TBn is detected. It is
possible to toggle TA on every underflow of TnCNT1 and thus generate a 50% duty cycle PWM signal on TAn.
This mode is a combination of modes 3 and 2. It allows timer/counter 2 to operate as a single-input capture timer concur-
rently with timer/counter 1. (Timer/counter 2 can be used as a system timer as described in mode 3.) Figure 50 shows a
block diagram of the timer in mode 4.
TnCNT1 starts counting down once a clock has been enabled. On underflow, TnCNT1 is reloaded from TnCRA register, and
counting proceeds downwards from that value. If enabled, the TAn pin toggles on every underflow of TnCNT1. Software can
select the initial value of TAn output signal as either high or low (see Section 4.7.5 on page 141 for additional details). In
addition, the TnAPND interrupt pending flag is set, and a timer interrupt 1 is generated if TnAIEN bit is set to 1 (see
Section 4.7.4 on page 140 for detailed information). Since TAn toggles on every underflow, a 50% duty cycle PWM signal
can be generated on TAn without requiring any interaction of software (and therefore the core).
TnCNT2 starts counting down once a clock has been enabled. When a transition is received on TBn, the value contained in
TnCNT2 is transferred to TnCRB, and the interrupt pending flag, TnBPND, is set. A timer interrupt 2 is generated if it is en-
abled. A preset of the counter to FFFF16 on detection of a transition on TBn can be enabled. In this case, the current value
of TnCNT2 is transferred to TnCRB, followed by a preset of the counter to FFFF16. TnCNT2 starts counting downwards from
FFFF16 until the next transition is received on TBn, which causes the procedure of capture and preset to be repeated. Un-
derflow of TnCNT2 sets the TnDPND interrupt pending flag and can also generate a timer interrupt 2 if the interrupt was
enabled (see Section 4.7.4 on page 140 for detailed information.). The input signal on TBn must have a pulse width equal
to or greater than one system clock cycle (see Section 7.6.10 on page 399 for additional details). TBn can be configured to
sense either rising or negative edge transitions.
Reload A
Timer/Counter 1
Reload B
Timer 1
Clock TA
TAIEN
TAPND
TnCNT1
TnCRA
TnCRB
TDIEN
TDPND
Timer
Interrupt 1
Timer
Interrupt 2
TAEN
Timer/Counter 2
TnCNT2
Timer 2
Clock
TBn
Clock
Selector
Underflow
Underflow
Figure 49. Mode 3, Dual Independent Timer
Embedded Controller Modules (Continued)
www.national.com 140 Revision1.07
PC87591E/S/L
Note that TnCNT2 can not operate in the Pulse Accumulate or External Event Counter modes since TBn input is used as a
capture input. Selecting either Pulse Accumulate mode or External Event Counter mode for TnCNT2 causes TnCNT2 to stop.
Note, however, that all available clock source modes may be selected for TnCNT1. Thus it is possible to use TnCNT1 to
determine the number of capture events on TBn or the elapsed time between capture events on TBn.
4.7.4 Timer Interrupts
The MFT16 contains a total of four interrupt sources that are mapped to two different system interrupts. All sources have a
pending flag associated with them and can be enabled or disabled under software control. The pending flags are TnXPND,
where n is the module and X is a letter from A to D. An interrupt enable flag, TnXIEN, is associated with each interrupt pend-
ing flag. Interrupt sources A, B or C can generate a timer interrupt 1; interrupt source D can generate a timer interrupt 2.
Note that not all interrupt sources are available in all modes. Table 19 shows which events can trigger an interrupt in each
mode of operation:
Table 19. MFT16 Interrupts
System
Interrupt
Interrupt
Pending
Flag
Mode 1 Mode 2 Mode 3 Mode 4
PWM and Counter Dual Input Capture Dual Independent
Timer Input Capture and
Timer
Timer
Int. 1
TnAPND TnCNT1 reload from
TnCRA Input capture on TAn
transition TnCNT1 reload from
TnCRA TnCNT1 reload from
TnCRA
TnBPND TnCNT1 reload from
TnCRB Input Capture on TBn
transition N/A Input Capture on TBn
transition
TnCPND N/A TnCNT1 underflow N/A N/A
Tier
Int. 2 TnDPND TnCNT2 underflow TnCNT2 underflow TnCNT2 reload from
TnCRB TnCNT2 underflow
Reload A
Timer/Counter 1
Capture B
Timer 1
Clock TAn
TAIEN
TAPND
TnCNT1
TnCRA
TnCRB
Timer
Interrupt 1
TATEN
Timer/Counter 2
TnCNT2
Timer 2
Clock
Underflow
TDIEN
TDPND
Timer
Interrupt 2
TBIEN
TBPND
Timer
Interrupt 1
TBn
TBEN
Preset
Figure 50. Mode 4, Input Capture and Timer
Embedded Controller Modules (Continued)
Revision 1.07 141 www.national.com
PC87591E/S/L
4.7.5 Timer I/O Functions
There are two I/O pins associated with each of the MFT16 modules: TAn and TBn, where n denotes the module on a given
device. The functionality of TA and TB depends on the mode of operation and the value of TAEN and TBEN bits. Table 20
shows the function of TA and TB versus the selected mode of operation. Note that if TA functions as a PWM output, the
initial and present value of TA is defined by TAOUT. For example, to start with TA high, TAOUT must be set (1) prior to
enabling the timer clock.
4.7.6 Operation in Development System
The MFT16 supports freezing the counters during breakpoints while operating in development systems. If FREEZE bit is
asserted, all timer counter clocks are inhibited, and the current values of timer/counter registers TnCNT1 and TnCNT2 are
frozen. Once FREEZE becomes inactive, counting resumes from the previous value. See 4.20.5 on page 273 for more de-
tails.
Table 20. MFT16 I/O Functions
I/O TnAEN
TnBEN
Mode 1 Mode 2 Mode 3 Mode 4
PWM and Counter Dual Input Capture Dual Independent
Timer Input Capture and
Timer
TAn
TnAEN=0
TnBEN=X No Output Capture TnCNT1
into TnCRA No Output toggle No Output toggle
TnAEN=1
TnBEN=X Toggle Output on
underflow of TnCNT1 Capture TnCNT1
into TnCRA and
preset TnCNT1 Toggle Output on
underflow of TnCNT1 Toggle Output on
underflow of TnCNT1
TBn
TnAEN=X
TnBEN=0 Ext. Event or Pulse
Accumulate Input Capture TnCNT1
into TnCRB Ext. Event or Pulse
Accumulate Input Capture TnCNT2
into TnCRB
TnAEN=X
TnBEN=1 Ext. Event or Pulse
Accumulate Input Capture TnCNT1
into TnCRB and
preset TnCNT1 Ext. Event or Pulse
Accumulate Input Capture TnCNT2
into TnCRB and
preset TnCNT2
Embedded Controller Modules (Continued)
www.national.com 142 Revision1.07
PC87591E/S/L
4.7.7 MFT16 Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
MFT16 Register Map
Timer/Counter Register 1 (TnCNT1)
The TnCNT1 register is a word-wide read/write register that is not altered by reset. The value on power-on is unknown.
Location: MFT16 1: 00 FD8016
MFT16 2: 00 FDA016
Type: R/W
Reload/Capture Register A (TnCRA)
The TnCRA register is a word-wide read/write register that is not affected by reset and thus contains random data on power-up.
Location: MFT16 1: 00 FD8216
MFT16 2: 00 FDA216
Type: R/W
Reload/Capture Register B (TnCRB)
The TnCRB register is a word-wide read/write register that is not affected by reset and thus contains random data on power-up.
Location: MFT16 1: 00 FD8416
MFT16 2: 00 FDA416
Type: R/W
Mnemonic Register Name Type
TnPRSC Clock Pre-Scaler Register R/W
TnCKC Clock Unit Control Register R/W
TnCNT1 Timer/Counter Register 1 R/W
TnCNT2 Timer/Counter Register 2 R/W
TnCRA Reload/Capture Register A R/W
TnCRB Reload/Capture Register B R/W
TnCTRL Timer Mode Control Register R/W
TnICTL Timer Interrupt Control Register R/W
TnICLR Timer Interrupt Clear Register WO
Bit 1514131211109876543210
Name TCNT1
Bit 1514131211109876543210
Name TCRA
Bit 1514131211109876543210
Name TCRB
Embedded Controller Modules (Continued)
Revision 1.07 143 www.national.com
PC87591E/S/L
Timer/Counter Register 2 (TnCNT2)
The TnCNT2 register is a word-wide read/write register that is not altered by reset. The power-up value is unknown.
Location: MFT16 1: 00 FD8616
MFT16 2: 00 FDA616
Type: R/W
Clock Pre-Scaler Register (TnPRSC)
The TnPRSC register is a byte-wide read/write register. It contains the current value of the clock pre-scaler, CLKPS. The
register is cleared on reset. It defines the timer clock pre-scaler ratio.
Location: MFT16 1: 00 FD8816
MFT16 2: 00 FDA816
Type: R/W
Clock Unit Control Register (TnCKC)
The TnCKC register is a byte-wide read/write register. It defines the clock source selection for each timer counter. The reg-
ister is cleared on reset, thus disabling timer/counter 1 and timer/counter 2 clocks.
Location: MFT16 1: 00 FD8A16
MFT16 2: 00 FDAA16
Type: R/W
Bit 1514131211109876543210
Name TCNT2
Bit 76543210
Name Reserved CLKPS
Reset 00000000
Bit Description
4-0 CLKPS (Clock Pre-Scaler). The timer clock is generated by dividing the system clock by CLKPS+1. Therefore
the maximum timer clock frequency is equal to the system clock (CLKPS=00000) and the minimum timer clock
is the system clock divided by 32 (CLKPS=11111).
7-5 Reserved.
Bit 76543210
Name Reserved C2CSEL C1CSEL
Reset 00000000
Bit Description
2-0 C1CSEL (Counter 1 Clock Select). Defines the clock mode for timer/counter 1 where:
Bits
2 1 0 Description
0 0 0: No Clock (Counter 1 stopped)
0 0 1: Prescaled system clock
0 1 0: External Event on TBn
0 1 1: Pulse Accumulate
1 0 0: Slow-speed Clock
Other: Reserved
Embedded Controller Modules (Continued)
www.national.com 144 Revision1.07
PC87591E/S/L
Timer Mode Control Register (TnCTRL)
The TnCTRL register is a byte-wide read/write register. It defines the mode of operation of timer/counter and TAn and TBn
I/O pins. The register is cleared on reset.
Location: MFT16 1: 00 FD8C16
MFT16 2: 00 FDAC16
Type: R/W
5-3 C2CSEL (Counter 2 Clock Select). Defines the clock mode for timer/counter 2.
Bits
5 4 3 Description
0 0 0: No Clock (Counter 1 stopped)
0 0 1: Prescaled system clock
0 1 0: External Event on TBn
0 1 1: Pulse Accumulate
1 0 0: Slow-speed Clock
Other: Reserved
7-6 Reserved.
Bit 76543210
Name Reserved TAOUT TBEN TAEN TBEDG TAEDG MDSEL
Reset 00000000
Bit Description
1-0 MDSEL (Mode Select). Defines the MFT16 mode of operation.
Bits
1 0 Description
0 0: Mode 1
0 1: Mode 2
1 0: Mode 3
1 1: Mode 4
2TAEDG (TAn Edge Polarity).
0: A high-to-low transition on TAn causes the action defined by the mode of operation (e.g., input capture).
1: A low-to-high transition on TAn results in the defined action.
3TBEDG (TBn Edge Polarity).
0: A high-to-low transition on TBn causes the action defined by the mode of operation (e.g., input capture or ex-
ternal event count)
1: A low-to-high transition on TBn results in the defined action
In Pulse Accumulate mode, when this bit is set to 1, the count is enabled if TBn is high. When cleared (0) and
while operating in Pulse Accumulate mode, the counter is enabled if TBn is low.
4TAEN (TAn Enable). Enables TAn to function either as a preset input or as a PWM output, depending on the
mode of operation.
If this bit is set (1), while operating in Dual Input Capture mode (mode 2), a transition on TAn causes TnCNT1
to be preset to FFFF16. In the remaining modes of operation, setting TnAEN enables TAn to function as a PWM
output. See Table 20 on page 141 for additional information.
5TBEN (TBn Enable). When set (1), and while operating in either Dual Input Capture mode (mode 2) or Input
Capture and Timer mode (mode 4), a transition on TBn causes the corresponding timer/counter to be preset to
FFFF16. In mode 2, TnCNT1 is preset to FFFF16; in mode 4, TnCNT2 is preset to FFFF16. The bit has no
effect while operating in any mode other than modes 2 or 4. See Table 20 on page 141 for additional
information.
Bit Description
Embedded Controller Modules (Continued)
Revision 1.07 145 www.national.com
PC87591E/S/L
Timer Interrupt Control Register (TnICTL)
The TnICTL register is a byte-wide read/write register. It contains the interrupt enable bit and associated interrupt pending
bits for the four timer interrupt sources. The TnICTL register format is shown below. The register is cleared on reset.
Location: MFT16 1: 00 FD8E16
MFT16 2: 00 FDAE16
Type: R/W
6TAOUT (TAn Output Data). Contains the value of TAn output when TAn is used as a PWM output.
0: TAn is low
1: TAn is high
This bit is set and cleared by hardware and thus reflects the status of TAn. This bit can be read at any time. It
may be used to set the initial value of TAn output in PWM mode. Note that if the hardware attempts to toggle
this bit at the same time as software is writing to the bit, the software write takes precedence over the hardware
update. This bit has no effect when TAn is used as input.
7Reserved.
Bit 76543210
Name TDIEN TCIEN TBIEN TAIEN TDPND TCPND TBPND TAPND
Reset 00000000
Bit Description
0TAPND (Timer Interrupt Source A Pending). When asserted, indicates that an interrupt condition (as shown
in Table 19 on page 140) has occurred. This bit can be set by either hardware or software.
This bit is cleared by a writing 1 to the respective bit in Timer Interrupt Clear register.
A write of 0 to this bit is ignored. The bit is cleared (0) on reset.
1Timer Interrupt Source B Pending (TBPND). Same as TAPND but for a different condition, as shown in
Table 19.
2Timer Interrupt Source C Pending (TCPND). Same as TAPND but for a different condition, as shown in
Table 19.
3Timer Interrupt Source D Pending (TDPND). Same as TAPND but for a different condition, as shown in
Table 19.
4TAIEN (Timer Interrupt A Enable).
0: No system interrupt occurs, but the associated pending flag TAPND is set
1: Enables a system interrupt based on the occurrence of a condition, as listed in Table 19
Note: The bit can be set or cleared by software at any time.
5TBIEN (Timer Interrupt B Enable).
0: No system interrupt occurs, but the associated pending flag TBPND is set
1: Enables a system interrupt based on the occurrence of a condition, as listed in Table 19
Note: The bit can be set or cleared by software at any time.
6TCIEN (Timer Interrupt C Enable).
0: No system interrupt occurs, but the associated pending flag TCPND is set
1: Enables a system interrupt based on the occurrence of a condition, as listed in Table 19
Note: The bit can be set or cleared by software at any time.
7TDIEN (Timer Interrupt D Enable).
0: No system interrupt occurs, but the associated pending flag TDPND is set
1: Enables a system interrupt based on the occurrence of a condition, as listed in Table 19
Note: The bit can be set or cleared by software at any time.
Bit Description
Embedded Controller Modules (Continued)
www.national.com 146 Revision1.07
PC87591E/S/L
Timer Interrupt Clear Register (TnICLR)
The TnICLR register is a byte-wide write-only register. It controls the clear of pending flags TAPND, TBPND, TCPND and
TDPND, which are located in TnICTRL register.
Location: MFT16 1: 00 FD9016
MFT16 2: 00 FDB016
Type: WO
Bit 76543210
Name Reserved TDCLR TCCLR TBCLR TACLR
Bit Description
0TACLR (Timer Pending A Clear). Writing a 1 to this bit clears the TAPND flag in TnICTL register.
0: Has no effect on TAPND. The previous value of TAPND is maintained
1: Causes the TAPND flag to be cleared (0)
1TBCLR (Timer Pending B Clear). Writing a 1 to this bit clears the TBPND flag in TnICTL register.
0: Has no effect on TBPND. The previous value of TBPND is maintained
1: Causes the TBPND flag to be cleared (0)
2TCCLR (Timer Pending C Clear). Writing a 1 to this bit clears the TCPND flag in TnICTL register.
0: Has no effect on TCPND. The previous value of TCPND is maintained
1: Causes the TCPND flag to be cleared (0)
3TDCLR (Timer Pending D Clear). Writing a 1 to this bit clears the TDPND flag in TnICTL register.
0: Has no effect on TDPND. The previous value of TDPND is maintained
1: Causes the TDPND flag to be cleared (0)
7-4 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 147 www.national.com
PC87591E/S/L
4.8 PULSE WIDTH MODULATOR (PWM)
ThePWMmodulegenerates eight 8-bit PWM outputs; each may have a different duty cycle. A common 8-bit clock pre-scaler
and an 8-bit down-counter determine the cycle time, the minimal possible pulse width and the duty cycle steps.
4.8.1 Features
Eight PWM outputs
One 8-bit fully programmable pre-scaler
One 8-bit fully programmable down-counter
8-bit duty cycle control per output
Programmable polarity per output
Low Power mode
4.8.2 Functional Description
The PWM generates eight 8-bit PWM outputs, PWM0 to PWM7. The Duty Cycle registers 0 to 7 (DCRi, i = 0 to 7) control
the duty cycle of PWM0 to PWM7 output signals, respectively. The Cycle Time register (CTR) controls the cycle time and
duty cycle steps of all outputs.
The PWM use the core domain clock as a reference for its activities. The pre-scaler divider divides the PWM input clock by
a pre-programmable ratio of 1:1 through 1:256, as defined by the Clock Pre-Scaler register (PRSC).
The PWM cycle is defined in terms of cycles of the pre-scaler output clock. It has a period of (CTR +1) cycles, out of which
the signal will be high for DCRi cycles. INVPi, when set, may be used to inverse this behavior.
The cycle period is defined by the 8-bit down-counter. It counts using the output clock from the pre-scaler divider, starting
from the value held in CTR register down to 0. When it reaches 0, the down-counter restarts from the CTR value.
The DCRi register defines the number of clock cycles during which PWMi signal is high during the complete down-counter
cycle.
If Inverse PWMi bit (INVPi) in PWM Polarity register (PWMPOL) is active (1), the DCRi register defines the number of clock
cycles during which PWMi signal is low in each of the down-counter complete cycles.
Figure 51 is a functional block diagram of the PWM module.
Figure 51. PWM Block Diagram
8-Bit Pre-Scaler
Counter
Input
Clock 8-Bit
Down-Counter
Cycle Time
Register
Duty Cycle
Register 0
Compare
Duty Cycle
Register 7
Compare
Clock Pre-Scaler
Register
S
R
Down-Counter == CTR
Q Q
PWM0
R
S
Q Q
PWM7
INVPi INVPi
0 1 0 1
Embedded Controller Modules (Continued)
www.national.com 148 Revision1.07
PC87591E/S/L
4.8.3 Cycle Time and Duty Cycle Calculation
The PWM module supports duty cycles in the range of 0% to 100%.
The PWMi output signal cycle time is:
(PRSC + 1) x (CTR + 1) x TCLK
where:
TCLK is the core domain clock cycle time (i.e., the PWM input clock).
The cycle time may range from 2 x TCLK to 65536 x TCLK.
The PWMi output signal duty cycle (in %, when INVPi is 0) is:
(DCRi + 1) / (CTR + 1) x 100.
Special cases:
If the DCRi value is greater than the CTR value, PWMi signal is always low.
If DCRi value is equal to the CTR value, PWMi signal is always high.
When Inverse PWMi bit is 1, the value of PWMi output is inverted. i.e., in the period described as 1 is 0 and vice versa.
4.8.4 Power Modes
The PWM is in Low Power mode when Power Mode bit (PWR) in PWM Control Register (PWMCNT) is 0. In this mode, the
PWM input clock is disabled (stopped), but the registers are accessible and maintained. The PWMi signal is 0 when INVPi
bit is 0; it is 1 when INVPi bit is 1.
The PWM is in normal power mode when PWR bit in PWMCNT register is 1. In this mode, the PWM module is enabled, its
registers are accessible and its clock is functional.
The PRSC and CTR registers should be updated during Low Power mode. Otherwise, there may be unpredictable transient
behavior.
4.8.5 PWM Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
PWM Register Map
Clock Pre-Scaler Register (PRSC)
The PRSC register controls the cycle time and the minimal pulse width. PRSC is cleared (0016) on reset.
Location: 00 FD0016
Type: R/W
Mnemonic Register Name Type
PRSC Clock Pre-Scaler R/W
CTR Cycle Time R/W
DCRi Duty Cycle 0 to 7 R/W
PWMPOL PWM Polarity R/W
PWMCNT PWM Control R/W
Bit 76543210
Name PRSC7-0
Reset 00000000
Bit Description
7-0 Pre-Scaler Divider Value. The divider of the PWM input clock is the number defined by PRSC7-0 + 1, e.g., a
value of 0016 results in a divide by 1, a value of FF16 results in a divide by 256.
The contents of this register may be changed only when the PWM module is in Low Power mode. Otherwise,
there may be unpredictable results.
Embedded Controller Modules (Continued)
Revision 1.07 149 www.national.com
PC87591E/S/L
Cycle Time Register (CTR)
The CTR register controls the cycle time and duty cycle steps, CTR is set (FF16) on reset.
Location: 00 FD0216
Type: R/W
Duty Cycle Registers 0 to 7 (DCRi)
The DCRi (i = 0 to 7) registers control the duty cycle of PWMi output signal. DCRi is cleared (0016) on reset.
Location: Channel 0 - 00 FD0816
Channel 1 - 00 FD0A16
Channel 2 - 00 FD0C16
Channel 3 - 00 FD0E16
Channel 4 - 00 FD1016
Channel 5 - 00 FD1216
Channel 6 - 00 FD1416
Channel 7 - 00 FD1616
Type: R/W
Bit 76543210
Name CTR7-0
Reset 11111111
Bit Description
7-0 Cycle Time Value. The 8-bit down-counter divides the pre-scaler output clock by the number defined by
CTR(7:0) + 1. For example, a value of 0016 results in a divide by 1, a value of FF16 results in a divide by 256.
The contents of this register may be changed only when the PWM module is in Low Power mode. Otherwise,
there may be unpredictable results.
Bit 76543210
Name DCRi7-0
Reset 00000000
Bit Description
7-0 Duty Cycle Value. DCRi register defines the number of clocks for which PWMi is high (from the full cycle of the
PWMi cycle), when Inverse PWMi bit in PWM Polarity register is 0.
If the DCRi value > CTR value, PWMi signal is always low.
If DCRi value == CTR value, PWMi signal is always high.
When Inverse PWMi bit is 1, the value of PWMi is inverse.
Embedded Controller Modules (Continued)
www.national.com 150 Revision1.07
PC87591E/S/L
PWM Polarity Register (PWMPOL)
This register controls the polarity of PWM0 to PWM7. The register is cleared (0016) on reset.
Location: 00 FD0416
Type: R/W
PWM Control Register (PWMCNT)
This register controls PWM operation. The register is cleared (0016) on reset.
Location: 00 FD0616
Type: R/W
Bit 76543210
Name INVP7-0
Reset 00000000
Bit Description
7-0 Inverse PWM Outputs. Each bit controls the corresponding polarity of PWM0 to PWM7; e.g., INVP0 controls
PWM0.
0: The number in DCRi indicates for how many clocks (of down-counter decrements) PWMi signal is high.
1: The number in DCRi indicates for how many clocks (of down-counter decrements) PWMi signal is low.
Bit 76543210
Name Reserved PWR
Reset 00000000
Bit Description
0Power Mode. This bit controls the operating mode of the PWM, as follows:
0: Low Power mode. PWM input clock is disabled (stopped). Its registers are accessible and maintained. PWMi
signal is 0 when INVPi bit is 0. PWMi signal is 1 when INVPi bit is 1.
1: Normal Power mode. PWM module is enabled. Its registers are accessible and its clock is functional.
7-1 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 151 www.national.com
PC87591E/S/L
4.9 UNIVERSAL SYNCHRONOUS/ASYNCHRONOUS RECEIVER-TRANSMITTER (USART)
TheUSARTisafull-duplexsynchronous/asynchronousreceiver-transmitter that supports a wide range of software program-
mable baud rates and data formats. It handles automatic parity generation and several error detection schemes. DMA trans-
fers are supported to enable fast processor-independent receive and transmit.
4.9.1 Features
Full duplex double-buffered receiver-transmitter
Synchronous operation
Asynchronous operation
Programmable baud rate between CLK/2 and CLK/32768 baud
Numerous framing formats
seven, eight or nine data bits
one or two stop bits
odd, even, mark, space or no parity
Hardware support of parity-bit generation during transmission and parity-bit check during reception
Interrupt on transmit buffer empty, receive buffer full and receive error conditions with separate enable
Software-controlled break transmission and detection
Software-controlled reset, enable/disable
Internal diagnostic capability
Automatic error detection
Parity Error
Framing Error
Data Overrun Error
9-bit Attention mode
DMA support for transmit and receive with separate enable
4.9.2 Functional Overview
The USART is composed of the following functional units:
Transmitter
Receiver
Baud rate generator
Control and error detection
Figure 52 shows a block diagram of the USART.
Embedded Controller Modules (Continued)
www.national.com 152 Revision1.07
PC87591E/S/L
Figure 52. USART Block Diagram
Each functional unit is described briefly in this section.
Transmitter
The Transmitter consists of an 8-bit transmit shift register and an 8-bit transmit buffer. Data is loaded in parallel from the
buffer into the shift register and then transmitted serially on the UTXD pin.
Receiver
The Receiver consists of an 8-bit receive shift register and an 8-bit receive buffer. Data is received serially into the shift reg-
ister from the URXD pin. After eight bits have been received, the contents of the shift register are transferred in parallel to
the receive buffer.
Baud Rate Generator
The Baud Rate Generator generates the clock for the Asynchronous and Synchronous modes of operation. It consists of
two registers and a two-stage counter. The registers are used to specify a pre-scaler value and baud rate divisor. The first
stage of the counter divides the CLK clock in 0.5 increments based on the value of the pre-scaler. The second stage of the
counter divides the output of the first stage in integer increments based on the value of the baud rate divisor.
Control and Error Detection
This unit contains the control registers (see Section 4.9.4 on page 158), control logic, error detection circuitry and parity gen-
erator/checker. It supports:
Selection of the data format, mode of operation, clock source and parity type
Generation and detection of parity
Reporting of parity errors
Detection and reporting of data overrun and frame errors
Interrupts on transmit buffer empty, receive buffer full, receive error and delta clear to send conditions
Generation and detection of line breaks
Peripheral Bus
sys_clk
Baud Clock
Baud Clock
USCLK
UTXD
URXD
Transmitter
Receiver
Control and
Error Detection
Parity
Generator/Checker
Baud Rate
Generator
Embedded Controller Modules (Continued)
Revision 1.07 153 www.national.com
PC87591E/S/L
4.9.3 Operation
The USART has two basic modes of operation; Synchronous and Asynchronous. In addition, two special Synchronous and
Asynchronous modes, attention and diagnostic, are available. This section describes the operating modes of the USART.
Asynchronous Mode
USARTAsynchronousmode enables the device to communicate with other devices using two communication signals: trans-
mit (UTXD) and receive (URXD).
In Asynchronous mode, Transmit Shift register (TSFT) and Transmit Buffer register (UTBUF) double buffer data for trans-
mission. To transmit a character, a data byte is loaded into UTBUF register. The data is then transferred to TSFT register.
While TSFT register is shifting out the current character (LSB first) on the UTXD pin, UTBUF register is loaded by software
with the next byte to be transmitted. When TSFT completes transmitting the last stop bit of the current frame, the contents
of UTBUF are transferred to TSFT register and the Transmit Buffer Empty flag (TBE) is set. The TBE flag is automatically
reset by the USART when the software loads a new character into UTBUF register. During transmission, the XMIP bit is set
high by the USART. This bit is reset only after the USART has sent the last stop bit of the current character and UTBUF
register is empty. UTBUF register is a read/write register. TSFT register is not user accessible.
In Asynchronous mode, the input frequency to the USART is 16 times the baud rate, i.e., there are 16 clock cycles per bit
time. In Asynchronous mode, the baud rate generator is always used as the UART clock.
Receive Shift register (RSFT) and Receive Buffer register (URBUF) double buffer the data being received. The USART re-
ceiver continually monitors the signal on the URXD pin for a low level to detect the beginning of a start bit. On sensing this
low level, the USART waits for seven input clock cycles and samples again three times. If all three samples still indicate a
valid low, the receiver considers this to be a valid start bit, and the remaining bits in the character frame are each sampled
three times around the mid-bit position. For any bit following the start bit, the logic value is found by majority voting, i.e., the
two samples with the same value define the value of the data bit. Figure 53 illustrates the process of start-bit detection and
bit sampling. Serial data input on the URXD pin is shifted into RSFT register. On receiving the complete character, the con-
tents of RSFT register are copied into URBUF register and Receive Buffer Full flag (RBF) is set. The RBF flag is automati-
cally reset when software reads the character from URBUF register. The RSFT register is not user accessible.
Figure 53. USART Asynchronous Communication
Synchronous Mode
The USART Synchronous mode enables the device to communicate with other devices using three communication signals:
transmit (UTXD), receive (URXD) and clock (USCLK). In this mode, data bits are transferred synchronously using the
USART clock signal. As shown in Figure 54, the data is transmitted on the rising edge and received on the falling edge of
the clock. Data is transmitted and received with the LSB first.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 116
SampleSample
STARTBIT DATA (LSB)
Sample
DATABIT
12345678910111213141516
1
16
Embedded Controller Modules (Continued)
www.national.com 154 Revision1.07
PC87591E/S/L
Figure 54. USART Synchronous Communication
In Synchronous mode, Transmit Shift register (TSFT) and Transmit Buffer register (UTBUF) double buffer data for transmis-
sion. To transmit a character, a data byte is loaded into TBUF register. The data is then transferred to TSFT register. The
TSFT shifts out one bit of the current character, LSB first, on each rising edge of the clock. While the TSFT is shifting out
the current character on the UTXD pin, UTBUF register can be loaded by the software with the next byte to be transmitted.
When TSFT completes transmitting the last stop bit within the current frame, the contents of UTBUF are transferred to TSFT
register, and the Transmit Buffer Empty flag (TBE) is set. The TBE flag is automatically reset by the USART when the soft-
ware loads a new character into UTBUF register. During transmission, XMIP bit is set high by the USART. This bit is reset
only after the USART has sent the last frame bit of the current character and UTBUF register is empty.
Receive Shift register (RSFT) and Receive Buffer register (URBUF) double buffer the data being received. Serial data input
on the URXD pin is shifted into RSFT register at the first falling edge of the clock. Each subsequent falling edge of the clock
causes an additional bit to be shifted into RSFT register. The USART assumes a complete character has been received after
the correct number of rising edges on USCLK (based on the selected frame format) has been detected. On receiving a com-
plete character, the contents of RSFT register are copied into URBUF register, and Receive Buffer Full flag (RBF) is set.
The RBF flag is automatically reset when software reads the character from URBUF register.
The transmitter and receiver may be clocked from either an external source available on the USCLK pin or the internal baud
rate generator. If the internal baud rate generator is used, the baud clock is output on the USCLK pin.
Attention Mode
Attention mode is available for networking this device with other processors. This mode requires the 9-bit data format with
no parity. The number of start/stop bits are user selectable. In this mode, two types of 9-bit characters are sent on the net-
work: address characters consisting of eight address bits and a “1” (one) in the ninth bit position and data characters con-
sisting of eight data bits and a “0” (zero) in the ninth bit position.
While in Attention mode, the USART receiver monitors the communication flow but ignores all characters until an address
character is received. On the receipt of an address character, the contents of Receive Shift register are copied to the receive
buffer. The RBF flag is set and an interrupt (if enabled) is generated. The ATN bit is automatically reset to zero, and the
USART begins receiving all subsequent characters. The software must examine the contents of URBUF register and re-
spond by accepting the subsequent characters (by leaving the ATN bit reset) or waiting for the next address character (by
setting the ATN bit again).
The operation of the USART transmitter is not affected by the selection of this mode. The value of the ninth bit to be trans-
mitted is programed by setting the STPXB9 bit appropriately. The value of the ninth bit received is read from the RB9 bit.
Diagnostic Mode
This mode is available for diagnostic tests of the USART. In this mode, the UTXD and URXD pins are internally connected,
and data that is shifted out of Transmit Shift register is immediately transferred to Receive Shift register. This mode supports
only the 9-bit data format with no parity. The number of start and stop bits is user selectable.
Frame Format Selection
The format shown in Figure 55 consists of a start bit, seven data bits (excluding parity) and one or two stop bits. If parity bit
generation is enabled by setting the PEN bit, a parity bit is generated and transmitted following the seven data bits.
USCLK
UTXD
URXD
Sample Input
Embedded Controller Modules (Continued)
Revision 1.07 155 www.national.com
PC87591E/S/L
Figure 55. Seven Data Bit Frame Options
The format shown in Figure 56 consists of one start bit, eight data bits (excluding parity) and one or two stop bits. If parity
bit generation is enabled by setting the PEN bit, a parity bit is generated and transmitted following the eight data bits.
Figure 56. Eight Data Bit Frame Options
The format shown in Figure 57 consists of one start bit, nine data bits and one or two stop bits. This format also supports
the USART attention feature. When operating in this format, all eight bits of UTBUF and URBUF are used for data. The ninth
data bit is transmitted and received using two bits in the control registers, called STPXB9 and RB9. Parity is not generated
or verified in this mode.
Figure 57. Nine Data Bit Frame Options
Baud Rate Generator
The Baud Rate Generator provides the basic baud clock from the system clock. The system clock is passed through a two-
stage divider chain consisting of a 5-bit baud rate pre-scaler (PSC) and an 11-bit baud rate divisor (DIV).
The correspondences between the 5-bit pre-scaler select (PSC) and pre-scaler factors are shown in Table 21.
1START
BIT 7-BIT DATA S
1a START
BIT 7-BIT DATA 2S
1c START
BIT 7-BIT DATA 2S
PA
1b START
BIT 7-BIT DATA S
PA
2START
BIT 8-BIT DATA S
2a START
BIT 8-BIT DATA 2S
2b START
BIT 8-BIT DATA S
PA
2c START
BIT 8-BIT DATA 2S
PA
3START
BIT 9-BIT DATA S
3a START
BIT 9-BIT DATA 2S
Embedded Controller Modules (Continued)
www.national.com 156 Revision1.07
PC87591E/S/L
A pre-scaler factor of zero corresponds to NO CLOCK. The NO CLOCK condition is the USART Power-Down mode. In this
mode, the USART clock is turned off in order to reduce power consumption. The user should set the pre-scaler factor to zero
(NO CLOCK) before selecting a new baud rate. Altering the baud rate while the USART is in operation could cause incorrect
data to be received or transmitted. UPSR register must contain a value other than zero when an external clock is used at
USCLK.
In Asynchronous mode, the baud rate is calculated by:
BR = SYS_CLK/(16 x N x P)
where:
BR is the baud rate
SYS_CLK is the system clock
N is the value of the baud rate divisor + 1
P is the pre-scaler divide factor selected by the value in the PSR register
The divide by 16 operation is performed because in Asynchronous mode, the input frequency to the USART is 16 times the
baud rate. In Synchronous mode, the input clock to the USART is equal to the baud rate.
Interrupts
The USART is capable of generating interrupts on one of the following conditions:
Receive Buffer Full
Receive Error
Transmit Buffer Empty
Table 21. Pre-Scaler Factors
Pre-Scaler Select Pre-Scaler Factor Pre-Scaler Select Pre-Scaler Factor
00000 NO CLOCK 10000 8.5
00001 1 10001 9
00010 1.5 10010 9.5
00011 2 10011 10
00100 2.5 10100 10.5
00101 3 10101 11
00110 3.5 10110 11.5
00111 4 10111 12
01000 4.5 11000 12.5
01001 5 11001 13
01010 5.5 11010 13.5
01011 6 11011 14
01100 6.5 11100 14.5
01101 7 11101 15
01110 7.5 11110 15.5
01111 8 11111 16
Embedded Controller Modules (Continued)
Revision 1.07 157 www.national.com
PC87591E/S/L
Figure 58 shows a diagram of the interrupt sources and associated enable bits.
The interrupts can be individually enabled or disabled using Enable Transmit Interrupt (ETI), Enable Receive Interrupt (ERI)
and Enable Receive Error Interrupt (EEI) bits in UICTRL register.
A transmit interrupt is generated when both the TBE and ETI bits are set. To remove this interrupt, the software must either
disable the interrupt by clearing the ETI bit or write to UTBUF register (thus clearing the TBE bit).
A receive interrupt is generated on two conditions:
If both the RBF and ERI bits are set. To remove this interrupt, the software must either disable the interrupt, by clear-
ing the ERI bit, or read from URBUF register (thus clearing the RBF bit).
If both the ERR and the EEI bits are set. To remove this interrupt, the software must either disable it by clearing the
EEI bit, or read USTAT register, which causes ERR flag to be cleared.
DMA Support
The USART can operate with either one or two DMA channels. Two DMA channels are required for processor-independent
full-duplex operation. Both receive and transmit DMA can be enabled individually.
If the transmit DMA is enabled (ETD=1), the USART issues a DMA request every time the TBE flag is set. Enabling the
transmit DMA automatically disables the TX interrupt independent of the value of the ETI bit.
Enabling the receive DMA (ERD=1) causes a DMA request to be asserted every time the Receive Buffer Full flag (RBF) is
set. Once the receive DMA is enabled the RX interrupt is automatically disabled independent of the value of the ERI bit.
However, to detect errors during reception the receive error interrupt should be enabled (EEI=1) while using the DMA.
Break Generation and Detection
A line break is generated when BRK bit is set in MDSL register. The UTXD line remains low until the user resets the BRK bit.
A line break is detected if URXD remains low for a time equivalent to 10 bit times or longer, after a missing stop bit has been
detected.
Parity Generation and Detection
Parity is only generated or checked with 7- and 8-bit data formats. It is not generated or checked in Diagnostic Loopback
mode, Attention mode or in Normal mode with 9-bit data format. Parity generation and checking is enabled and disabled via
PEN bit in UFRS register. PSEL bits in UFRS register are used to select odd, even, mark or space parity.
ISE Mode Operation
The USART module supports breakpoint operation by preserving some of the status bits of the USTAT and UICTRL regis-
ters. While the FREEZE bit is asserted, the PE, FE, DOE, BKD and DCTS bits are not cleared on a read of STAT register.
EEI
ERI
ERR
RBF
FE
DOE
PE RX
Interrupt
ETI
TBE TX
Interrupt
Figure 58. USART Interrupt Sources
Embedded Controller Modules (Continued)
www.national.com 158 Revision1.07
PC87591E/S/L
4.9.4 USART Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
USART Register Map
Receive Data Buffer Register (URBUF)
Location: 00 FD2216
Type: RO
Transmit Data Buffer Register (UTBUF)
Location: 00 FD2016
Type: R/W
Baud Rate Pre-Scaler Register (UPSR)
Byte-wide read/write register containing the 5-bit pre-scaler value in bit 7 (MSB) through bit 3 (LSB) and the upper three bits
of the baud divisor in bit 2 (MSB) through bit 0 (LSB). The register is cleared (0016) on reset.
Location: 00 FD2E16
Type: R/W
Baud Rate Divisor Register (UBAUD)
This byte-wide read/write register contains the lower eight bits of the baud rate divisor. The UPSR register contains the upper
three bits. The register is cleared (0016) on reset.
Location: 00 FD2C16
Type: R/W
Mnemonic Register Name Type
URBUF Receive Data Buffer Register RO
UTBUF Transmit Data Buffer Register R/W
UPSR Baud Rate Pre-Scaler Register R/W
UBAUD Baud Rate Divisor Register R/W
UFRS Frame Select Register R/W
UMDSL Mode Select Register R/W
USTAT Status Register RO
UICTRL Interrupt Control Register Varies per bit
Bit 76543210
Name URBUF
Bit 76543210
Name UTBUF
Bit 76543210
Name UPSC UDIV[10]: UDIV[8]
Reset 00000000
Bit 76543210
Name UDIV[7]: UDIV[0]
Reset 00000000
Embedded Controller Modules (Continued)
Revision 1.07 159 www.national.com
PC87591E/S/L
Frame Select Register (UFRS)
This byte-wide read/write register controls the selection of the frame format, including number of data bits, number of stop
bits and parity. The register is cleared (0016) on reset.
Location: 00 FD2816
Type: R/W
Bit 76543210
Name Reserved PEN PSEL XB9 STP CHAR
Reset 00000000
Bit Description
1-0 CHAR. Selects the number of data bits per frame. Note that the parity bit is not included in the number of data
bits.
Bits
1 0 Description
0 0: Frame contains eight data bits
0 1: Frame contains seven data bits
1 0: Frame contains nine data bits
1 1: Loopback mode selected; frame contains nine data bits.
2STP. Programs the number of stop bits to be transmitted.
0: One stop bit transmitted
1: Two stop bits transmitted
3XB9. Contains the value of the 9th data bit for transmission only. The bit has no effect while operating with seven
or eight data bits per frame.
0: Transmit 0 as 9th data bit
1: Transmit 1 as 9th data bit
5-4 PSEL. Controls the mode of parity bit generation and checking. Note that while operating with nine data bits-
per-frame, the parity bit is omitted. In this case, the value of PSEL has no effect.
Bits
5 4 Description
0 0: Odd parity
0 1: Even parity
1 0: Mark (1)
1 1: Space (0)
6PEN. Enables or disables the generation of a parity bit generation and parity check. Note that there is no parity
bit while operating in the nine data bits-per-frame mode. In this case, this bit has no effect.
0: Parity disabled
1: Parity enabled
7Reserved.
Embedded Controller Modules (Continued)
www.national.com 160 Revision1.07
PC87591E/S/L
Mode Select Register (UMDSL)
This byte-wide read/write register controls the selection of the clock source, Synchronous mode, Attention mode and line
break generation. It contains the enable bits for the DMA channels. The register is cleared (0016) on reset.
Location: 00 FD2A16
Type: R/W
Bit 76543210
Name Reserved ERD ETD CKS BRK ATN MOD
Reset 00000000
Bit Description
0MOD. Selects the Synchronous or Asynchronous mode of operation:
0: Asynchronous mode
1: Synchronous mode
1ATN. Selects the Attention mode of operation. Cleared by hardware after reception of an address frame that is
a 9-bit character with a “1” in the ninth bit position.
0: Disable Attention mode
1: Enable Attention mode
2BRK. Setting the bit (1) causes UTXD to go low. UTXD remains low until the bit is cleared (0) by the user.
3CKS. Controls the source of the clock while operating in Synchronous mode (MOD=1).
0: USART operates from the baud rate generator and outputs the baud rate clock on USCLK
1: USART operates from an external clock provided on USCLK
While the USART is operated in Asynchronous mode (MOD=0), the bit has no effect.
4ETD.
0: No DMA request is asserted for transmit operations
1: DMA request is asserted when the Transmit Buffer Empty (TBE) flag is set (1)
5ERD.
0: No DMA request is asserted for receive operations
1: DMA request is asserted when the Receive Buffer Full (RBF) flag is set (1)
7-6 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 161 www.national.com
PC87591E/S/L
Status Register (USTAT)
This byte-wide, read-only register contains the receive and transmit status bits. The register is cleared (0016) on reset.
Location: 00 FD2616
Type: RO
Bit 76543210
Name Reserved XMIP RB9 BKD ERR DOE FE PE
Reset 00000000
Bit Description
0PE. The bit is set when a parity error is detected within a received character. The bit is cleared by the hardware
when USTAT register is read.
0: No parity error detected
1: Parity error detected in a received byte since the last time USTAT was read
1FE. The bit is set when the USART fails to receive a valid stop bit at the end of a frame. Automatically cleared
on read of USTAT.
0: No framing error detected
1: Framing error detected on a received byte since the last time USTAT was read
2DOE. The bit is set when a new character is received and transferred to RBUF before the software has read the
previous character. Automatically cleared on read of the USTAT.
0: No data overrun error detected
1: Data overrun error detected since the last time USTAT was read
3ERR. The bit is set any time DOE, FE or PE is set. Automatically cleared if DOE, FE and PE are all zero. This
bit is read only. Any attempt to write to the bit by software does not alter its present value.
0: No DOE, FE or PE has occurred since the last time USTAT register was read.
1: A DOE, FE or PE error has occurred since the last time USTAT register was read.
4BKD. If set, indicates that a line break condition has occurred. A break condition is detected if RXD remains low
for a least ten bit times after a missing stop bit has been detected at the end of a frame. The bit is cleared under
the following conditions:
On a read of USTAT register, if the break condition on RXD is no longer present. If RXD is still low when USTAT
register is read, the bit is not cleared.
If the read of USTAT register did not cause the bit to be cleared because the break condition on RXD was still
in effect, the hardware clears the bit as soon as the break condition no longer exists, i.e., RXD returns to a high
level.
5RB9. Contains the ninth data bit of the last frame received when operating with the 9-bit data format.
0: “0” received in ninth bit position
1: “1” received in ninth bit position
6XMIP. Indicates that the USART is transmitting data. It is reset by hardware at the end of the last frame bit.
0: USART is not transmitting
1: USART is transmitting
7Reserved.
Embedded Controller Modules (Continued)
www.national.com 162 Revision1.07
PC87591E/S/L
Interrupt Control Register (UICTRL)
This byte-wide register contains the interrupt enable bits and the interrupt status flags. The register is set to 0116 on reset.
Location: 00 FD2416
Type: Varies per bit
4.9.5 Usage Hints
Calculating the Baud Rate in Asynchronous Mode
The equation for calculating the baud rate is:
BR = SYS_CLK/(16xNxP)
where:
BR is the baud rate
SYS_CLK is the system clock
N is the value of the baud rate divisor + 1
P is the pre-scaler divide factor selected by the value in the PSR register
Assuming a system clock of 5 MHz and a desired baud rate of 9600, the NxP term, according to the equation above, is:
NxP = (5x106)/(16x9600) = 32.552
The NxP term is then divided by each pre-scaler factor in Table 21 on page 156 to obtain a value closest to an integer. The
factor for this example is 6.5:
N = 32.552/6.5 = 5.008 (N = 5)
Bit 76543210
Name EEI ERI ETI Reserved RBF TBE
Reset 00000001
Bit Type Description
0ROTBE. The bit is set by the hardware when the USART transfers data from UTBUF register to TSFT
register for transmission. It is automatically cleared on the next write to UTBUF register. The bit is set
on reset.
0: Transmit buffer not empty
1: Transmit buffer empty
1RORBF. The bit is set by the hardware when the USART has received a complete data frame and
transferred the data from RSFT register to URBUF register. The bit is automatically cleared when
RBUF register is read.
0: Receive buffer not full. New data has not been transferred to RBUF since the last time it was read.
1: Receive buffer full. RBUF contains new data since the last time it was read.
4-2 Reserved.
5 R/W ETI. An interrupt is generated when the TBE flag is set. Read/write bit.
0: Disable transmitter interrupt
1: Enable transmitter interrupt
6 R/W ERI. An RX interrupt is generated when the RBF flag is set. Read/write bit.
0: Disable receiver interrupt
1: Enable receiver interrupt
7 R/W ETI. An RX interrupt is generated when the ERR flag is set, indicating that a receive error has
occurred.
0: Disable receive error interrupt
1: Enable receive error interrupt
Embedded Controller Modules (Continued)
Revision 1.07 163 www.national.com
PC87591E/S/L
The baud rate register is programed with a baud rate divisor of 4 (N = baud rate divisor +1). This produces a baud clock of:
BR = (5x106)/(16x5x6.5) = 9615.385
% error = (9615.385-9600)/9600 = 0.16
Note that the percent error is much lower than would be possible without the non-integer pre-scaler factor. Refer to the table
below for more examples.
Calculating the Baud Rate in Synchronous Mode
The equation for calculating the baud rate is:
BR = SYS_CLK/(2xNxP)
where:
BR is the baud rate
SYS_CLK is the system clock
N is the value of the baud rate divisor + 1
P is the pre-scaler divide factor selected by the value in the PSR register
The same procedure is used for determining the values of N and P, as in Asynchronous mode. However, non-integer pre-
scale values are not allowed.
System Clock Desired
Baud Rate N P Actual Baud Rate Percent Error
4 MHz 9600 2 13 9615.385 0.16
5 MHz 9600 5 6.5 9615.385 0.16
10 MHz 19200 5 6.5 19230.769 0.16
20 MHz 19200 5 13 19230.769 0.16
Embedded Controller Modules (Continued)
www.national.com 164 Revision1.07
PC87591E/S/L
4.10 TIMER AND WATCHDOG (TWD)
The Timer and WATCHDOG module (TWD) generates the clocks and interrupts used for timing periodic functions in the
system. It also provides WATCHDOG protection over software execution.
The TWD provides flexibility in system configuration by enabling the configuration of various clock ratios. After setting the
TWD configuration, the software can lock it to give a higher level of protection against erroneous software action. Once a
section of the TWD is locked, only reset releases it. See Figure 59 for the TWD block diagram.
4.10.1 Features
32.768 KHz input clock
Programmable pre-scale counter
16-bit programmable periodic interrupt timer
8-bit WATCHDOG counter
WATCHDOG signal generation in response to failure detection, such as:
WATCHDOG service performed too early
WATCHDOG service performed too late
Wrong DATA used in a service by data match
4.10.2 Functional Description
Input Clock
The TWD bases all its counting activities on a 32.768 KHz clock. The WATCHDOG can count using a division of the 32 KHz
clock (either T0OUT or T0IN).
(TWCP)
32.768 KHz
16-Bit Timer
5-Bit Pre-Scale
Counter
WATCHDOG
Peripheral Bus
T0OUT
WATCHDOG
T0IN
FREEZE
TWDT0 Register
WDCNT
WDSDM WATCHDOG
Service
Logic
Figure 59. Timer and WATCHDOG Block Diagram
from RTC
(DEV Env. only)
to ICU
WDCT0I bit (TWCFG Register)
T0IN
to ACM
Signal
to Reset Circuit
Embedded Controller Modules (Continued)
Revision 1.07 165 www.national.com
PC87591E/S/L
Pre-Scale
A pre-scale counter divides the input clock (32.768 KHz) by a factor of 2MDIV. MDIV in TWCP register is in the range of 0
through 5 (i.e., divide ratio of 1:1 through 1:32). The pre-scaled output is used as an input clock for a 16-bit timer (TWDT0)
and is referred to as T0IN.
TWD Timer 0
TWD Timer 0 is a 16-bit, programmable, automatically re-triggered down-counter. It countson the rising edge ofT0IN.It starts
from the value loaded to TWDT0 register down to zero and then restarts counting from TWDT0 at the next T0IN cycle.
When the counter reaches 0, T0OUT is set (1) for one T0IN cycle. This makes the Timer 0 cycle:
(TWDT0 + 1) x T0IN-cycle.
T0OUT is input to the ICU and can be used as the time base for activities such as system tick.
When TWDT0 is loaded with a new value, the counter uses it the next time it restarts counting (i.e., after reaching zero). If
RST in Timer Control register (T0CSR) is written 1, the timer is restarted on the next rising edge of T0IN.
Notes:
RST bit in T0CSR register is cleared after completing this load.
When MDIV in TWCP register is 0, the timer counter may skip one count when loaded with a new value.
WATCHDOG Operation
The WATCHDOG is an 8-bit down counter, operating on the rising edge of its currently selected clock source. On reset, it
is disabled (i.e., it does not count and no WATCHDOG signal is generated). A write to the WATCHDOG Count register
(WDCNT) or the WATCHDOG Service Data Match (WDSDM) register either starts the counter or, if WATCHDOG is already
running, performs a restart (“touch”) operation. Once the WATCHDOG is counting down, only a reset can stop it.
Writing to WDCNT register is enabled while LWDCNT in TWCFG register is 0. A write to WDCNT starts the WATCHDOG,
and it begins counting down from the written value. If the service on data match is enabled (WDSDME in TWCFG register
is 1), writing to WDSDM register with 5C16 restarts the WATCHDOG counter from the value stored in WDCNT.
A WATCHDOG signal is triggered if one of the following occurs:
The counter reaches zero (too late service).
The WATCHDOG is written to more than once per WATCHDOG clock cycle for the currently selected clock (too early
service). Writing to the WATCHDOG more than once per three WATCHDOG clock cycles (for the currently selected
clock) may cause the WATCHDOG signal to trigger.
Data other than 5C16 is written to WDSDM when WDSDME in TWCFG register is 1.
WATCHDOG Clock Source Selection
Select the clock source as follows:
WDCT01 bit in TWCFG register is 0: T0OUT
WDCT01 bit in TWCFG register is 1: T0IN
Changing the WATCHDOG clock source may cause it to gain or lose one clock cycle.
Notes:
When MDIV in TWCP register is 0, the WATCHDOG counter may skip one count when loaded with a new value.
After activating WATCHDOG, avoid entering Idle mode in the first four low-frequency clock cycles.
TWD Control and Configuration
The TWD Configuration register (TWCFG) allows you to:
Set the WATCHDOG clock source: T0IN or T0OUT
Enable WATCHDOG service on write to WDSDM register
Define which of TWCFG, TWCPR, TWDT0, T0CSR and WDCNT is locked.
Once LTWCFG, LTWCP, LTWDT0 or LWDCNT, in TWCFG register, is set its respective resources are locked and can be
cleared only by reset. Setting any of these registers prevents runaway software from tampering with the respective WATCH-
DOG function.
Operation in Idle Mode
The TWD is active in Idle mode: the counters continue to function, and interrupts and error signals are issued.
Write operations to TWCP, TWDT0 and WDCNT may be delayed by up to three 32.768 KHz clock cycles. The software should
avoid entering Idle mode during this period. WDTLD bit in T0CSR register indicates when it is safe to switch power modes.
Embedded Controller Modules (Continued)
www.national.com 166 Revision1.07
PC87591E/S/L
4.10.3 TWD Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
TWD Register Map
Timer and WATCHDOG Configuration Register (TWCFG)
The TWCFG register is a byte-wide, read/write register. It defines the WATCHDOG clock input and service method and en-
ables TWD control register locking. Setting the required configuration and locking the TWCFG stops the software from in-
terfering with the WATCHDOG operation. On reset, non-reserved bits of TWCFG are initialized to 0.
Location: 00 FEE016
Type: R/W
Mnemonic Register Name Type
TWCFG Timer and WATCHDOG Configuration Register R/W
TWCP Timer and WATCHDOG Clock Pre-Scaler Register R/W
TWDT0 TWD Timer 0 Register R/W
T0CSR TWDT0 Control and Status Register R/W
WDCNT WATCHDOG Count Register WO
WDSDM WATCHDOG Service Data Match Register WO
Bit 76543210
Name Reserved WDSDME WDCT0I LWDCNT LTWDT0 LTWCP LTWCFG
Reset 00000000
Bit Description
0LTWCFG.
0: Enables read/write from/to TWCFG register
1: Any data written to it is ignored and reading from it returns unpredictable values
Once LTWCFG is set, it can only be cleared by reset.
1LTWCP.
0: Enables read/write from/to TWCP register
1: Any data written to it is ignored and reading from it returns unpredictable values
Once LTWCP is set, it can only be cleared by reset.
2LTWDT0.
0: Enables read/write from/to TWDT0 and T0CSR registers
1: Registers cannot be written to and TWDT0 cannot be read. Any data written to TWDT0 or T0CSR is ignored.
Reading from TWDT0 returns unpredictable values.
Once LTWDT0 is set, it can only be cleared by reset.
3LWDCNT.
0: Enables write to WDCNT register
1: Any data written to it is ignored and reading from it returns unpredictable values
Once LWDCNT is set, it can only be cleared by reset. When WDSDME bit is cleared, touch operations (i.e.,
writing to WDCNT register) may be performed when LWDCNT bit is either 0 or 1.
4WDCT0I.
0: Selects T0OUT clock as the WATCHDOG clock
1: Selects T0IN as the input clock
The hardware clock source selection overrides this clock selection.
Embedded Controller Modules (Continued)
Revision 1.07 167 www.national.com
PC87591E/S/L
Timer and WATCHDOG Clock Pre-Scaler Register (TWCP)
The TWCP register is a byte-wide, read/write register. It defines the pre-scale ratio of the input clock and generates the T0IN
clock. On reset, the non-reserved bits of TWCP are initialized to 0.
Location: 00 FEE216
Type: R/W
TWD Timer 0 Register (TWDT0)
The TWDT0 register is a read/write register. It defines the T0OUT interrupt rate. On reset, this register is initialized to
FFFF16.
Location: 00 FEE416
Type: R/W
5WDSDME. Selects the WATCHDOG touch mechanism
0: Disables the WATCHDOG service using WDSDM register. In this case, the WATCHDOG should be serviced
by writing a value to WDCNT register. When this bit is cleared, write operations to WDSDM are ignored.
1: Selects the use of data match using the WDSDM mechanism.
7-6 Reserved.
Bit 76543210
Name Reserved MDIV
Reset 00000000
Bit Description
2-0 MDIV. Defines the pre-scale ratio of the input clock. The pre-scale ratio is 2MDIV. The value of MDIV must be in
the range of 0-5, providing a pre-scale ratio of 1 to 32.
MDIV allowed values:
Bits
2 1 0 Clock Ratio
0 0 0: 1:1
0 0 1: 1:2
0 1 0: 1:4
0 1 1: 1:8
1 0 0: 1:16
1 0 1: 1:32
Other Reserved
7-3 Reserved.
Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Name PRESET
Reset 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Bit Description
15-0 PRESET. Defines the counter preset value. Whenever the counter reaches zero, it starts counting down from
this value. The T0OUT frequency is the T0IN frequency divided by (PRESET+1). The allowed values of the
PRESET field are 000116 through FFFF16.
Bit Description
Embedded Controller Modules (Continued)
www.national.com 168 Revision1.07
PC87591E/S/L
TWDT0 Control and Status Register (T0CSR)
The T0CSR register is a read/write register. It controls the operation and provides the status of the T0 timer. The non-re-
served bits of T0CSR are cleared (0) on reset.
Location: 00 FEE616
Type: R/W
WATCHDOG Count Register (WDCNT)
The WDCNT register is a byte-wide, write-only register. It holds the value loaded into the WATCHDOG counter when it is
touched and counts down from it. The WATCHDOG is started by the first write to the register. Each successive write restarts
the WATCHDOG counter. A write to WDCNT functions as a touch operation when WDSDME bit TWCFG register is cleared,
even if WDCNT is locked; in this case, the WATCHDOG counter is restarted using the value loaded in PRESET field before
WDCNT was locked (i.e., the new PRESET value is ignored). On reset this register is initialized to 0F16.
Location: 00 FEE816
Type: WO
WATCHDOG Service Data Match Register (WDSDM)
The WDSDM register is a byte-wide, write-only register. When WDSDME in TWCFG register is set, the WATCHDOG count-
ing restarts from the value in WDCNT, when WDSDM is written with 5C16. If any other data is written to this register, it trig-
gers a WATCHDOG signal. If RSDATA is written more than once per three WATCHDOG clock cycles, a WATCHDOG signal
is also triggered. When the WDSDME bit is cleared, a write to this register is ignored.
Location: 00 FEEA16
Type: WO
Bit 76543210
Name Reserved WDLTD Reserved TC RST
Reset 00000000
Bit Description
0RST (Reset). When set (1), forces the timer to restart counting in the next input clock rising edge. The bit is
cleared by the input clock rising edge, indicating that the counter resumed its automatic re-triggerable operation.
Writing 0 to this bit is ignored.
1TC (Terminal Count). Indicates that the counter has reached zero (terminal count). This bit is cleared each time
the register is read. It is a read-only bit and data written to it is ignored.
2Reserved.
3WDLTD (WATCHDOG Last Touch Delay). The bit is set when the WDCNT is written. It is cleared after
WATCHDOG is updated. (After WATCHDOG is updated, it is safe to switch to Idle mode.)
7-4 Reserved.
Bit 76543210
Name PRESET
Reset 00001111
Bit Description
7-0 PRESET. Defines the counter preset value.
Bit 76543210
Name RSDATA
Bit Description
7-0 RSDATA.
Embedded Controller Modules (Continued)
Revision 1.07 169 www.national.com
PC87591E/S/L
4.10.4 Usage Hints
The TWD protects WATCHDOG operation from software tampering. To achieve the highest level of protection, proceed as
follows:
1. Program the TWDT0 pre-scale and TMWT0 timers to the desired values.
2. Configure the WATCHDOG clock to use T0IN or T0OUT using WDCT0I bit in TWCFG register.
3. Program the WDCTL to the maximum period between WATCHDOG touch operations. Note that from this point, the
WATCHDOG starts operating and must be touched periodically to prevent a WATCHDOG error signal.
4. Configure the WATCHDOG to use data match, and lock all the TWD configuration and setting registers by setting bits 0
through 4 and bit 6 of the TWCFG.
5. Touch the WATCHDOG by writing 5C16 to WDSDM at the appropriate rate (i.e., no more than once every WATCHDOG
clock cycle and no less than the period programed to WDCTL).
Embedded Controller Modules (Continued)
www.national.com 170 Revision1.07
PC87591E/S/L
4.11 ANALOG TO DIGITAL CONVERTER (ADC)
The Analog to Digital Converter (ADC) monitors various voltages and temperatures in the system and reports their values
to the core.
The ADC can measure up to 10 external voltage inputs and four internal voltage sources, with 10-bit resolution. The internal
voltage sources measure the VDD,V
CC,AV
CC and VBAT supplies. VDD,V
CC and AVCC are divided by 2 to allow both over-
voltage and undervoltage detection. The external voltage inputs support thermistor-based temperature measurement.
The ADC can measure up to two, diode-based temperature sources with 1oC resolution. The current generated by the ADC
module causes a voltage drop on a remote (external) or local (internal) diode. This voltage is measured by the ADC and
converted to temperature units. An Overtemperature Shutdown (OTS) interrupt becomes active when the temperature of the
internal diode exceeds a programmable limit.
The ADC executes cycles of one temperature and three voltage measurements, each assigned to a separate output chan-
nel. The temperature channel measures the two temperature sources (remote and local) in consecutive cycles. Each of the
three voltage channels measures one selected voltage input during the cycle.
4.11.1 Features
Voltage measurement
Ten external voltage inputs and four internal power supply inputs
10-bit resolution
0 to 2.97V input voltage range
High-impedance, ground-referenced inputs
Enables thermistor-based temperature measurement
Diode-based temperature measurement
one remote (external) diode input and one local (internal) diode
1oC/bit resolution
40oC to +125oC range (using the remote diode)
Open/short detection for the remote diode connection
Hardware-monitored, local overtemperature detection
Internal high-precision reference
Digital reading output channels
Three voltage buffers and one temperature buffer (diode)
Input selection for each voltage channel
Sampling sequence and timing
Three voltage and one temperature measurement within 100 ms.
Cyclic measurement of the four output channels
Separate enable for each channel
Programmable conversion-start delay to guarantee input settling time
Polling- or interrupt-driven interface
Power consumption
Zero current when disabled
Low operating current
4.11.2 Functional Description
Inputs. The ADC has 16 inputs (AI0-13, AI15, AI16) divided in three groups:
External Voltage (AI0-9). These are either general-purpose, positive DC voltage sources or temperature-dependent
voltage generated by using a Negative/Positive Temperature Coefficient (NTC/PTC) thermistor in a resistive divider.
Internal Voltage (AI10-13) These are internally connected to the supply voltages of the device (VDD,V
CC,AV
CC and
VBAT). Voltages higher than the full-scale voltage (VFS) are divided by 2, except for VBAT which is not divided in order
to minimize the current drain.
Diode-Based Temperature Inputs (AI15, AI16). These are temperature-dependent voltage drops, on a remote and a
local diode, caused by the flow of a current generated by the ADC. Since the AI8 and AI9 voltage inputs use the
same package pins as the remote diode (DP, DN), only one option (voltages or diode) is available at a time.
Embedded Controller Modules (Continued)
Revision 1.07 171 www.national.com
PC87591E/S/L
Temperature Sensor Interface (TSI). The TSI generates the diode current and converts the voltage drop to a single-ended
voltage. In addition, the TSI of the remote diode enables open/short detection for the diode connection cable and sets the
corresponding status bits.
Analog Multiplexer. A 16 to 1 analog multiplexer selects one of the inputs for measurement by connecting it to the A/D con-
verter. Switching between inputs at different voltage levels requires delaying the conversion start until the input voltage to
the A/D converter has settled to the desired accuracy.
A/D Converter. The Σ−∆, high-resolution A/D converter receives the selected input and converts it. The result of the con-
version is either a 10-bit, unsigned integer digital value (0 to 1023) for voltage inputs or an 8-bit, 2s complement digital value
(128 to +127) with the Least Significant Bit (LSB) having the value of 1°C for temperature inputs.
A high-precision internal reference generator sets the full-scale voltage value (VFS) of the A/D converter.
ADC Cycle. The ADC has four output “channels”: one for temperature and three for voltage measurement. The voltage
measurement channels are not related to specific inputs. They hold the input select control data for the next measurement
and contain a buffer in which the conversion result is stored. The temperature channel is slightly different, since it lacks the
input select control data. It “toggles” between the remote and local diode inputs, unless the remote diode input is disabled.
An ADC cycle includes measurements of all four channels and a calibration operation. The first measurement is of the tem-
perature channel, followed by a calibration measurement and the three voltage channels in ascending order, each for the
specific input number contained in its control register. The ADC waits for a programmable delay between the selection of an
input and the A/D conversion start that is necessary for A/D input settling to the required accuracy.
At the end of each A/D conversion, the result is stored in the corresponding buffer and a Data Valid (DATVAL) flag is set.
At the end of the ADC cycle, a flag is set indicating that all the channels contain new data. If enabled, an interrupt request
is sent to the core.
After reading the data at the end of the cycle, the software may choose to set up new values for the input select control data
inorderto measure different inputs during the following cycle. Another option is to use the old values for one or more voltage
channels and repeat the measurement on the previous inputs for a higher sampling rate. Any voltage output channel may
be disabled in order to skip its related measurement during the ADC cycle (shorter cycle).
Digital Comparator. A digital comparator checks the temperature measured by the local diode by comparing it with a user-
programmable limit. When the temperature of the PC87591x exceeds the Overtemperature Limit, the Overtemperature
Shutdown (OTS) signal becomes active and an interrupt request (if enabled) is sent to the core.
ADC Control/Status Registers and Data Out Buffers. These maybe read/writtenbythe corethrough thePeripheralbus.
Timing Control. This block reduces the frequency of the system clock to the lower value required by the ADC.
Embedded Controller Modules (Continued)
www.national.com 172 Revision1.07
PC87591E/S/L
Remote
Diode
AD0
DN
DP
Temp
Sensor
Interface
AI15
Temp
Sensor
Interface
AI16
AI0
AI1
AI2
AI3
AI4
AI5
AI6
AI7
AI8
AI9
AI10
AI11
AD9
AI12
AI13
VDD
VCC
VBAT
AVCC
16:1
Analog
MUX
A/D Converter
VREF
Voltage
Temperature
Channel
Channel 1
Channel 2
Channel 3
Voltage
Voltage
+
Status and
Control
Limit
Overtemp
OTS
Timing
Control
Interrupt
System
ADC Clock
Delay
Peripheral Bus
AGND
AVCC
Analog
Power
3.3V
ADC
Clock
Σ−∆
Figure 60. ADC Functional Diagram
Local
Diode
Embedded Controller Modules (Continued)
Revision 1.07 173 www.national.com
PC87591E/S/L
4.11.3 Voltage Measurement
The ADC performs a linear conversion of the input voltage signal to a 10-bit, unsigned digital representation. The input signal
should be applied relative to the AGND pin and should range from 0V to VFS (Full Scale).
The equations in the folowing table should be used to calculate the input voltage based on the reading from the Voltage
Channel Data result (VCHDAT field in VCHiDAT register).
An input signal of zero (ground) is converted to 00016; an input signal equal to (1023/1024) * VFS is converted to 3FF16.
Changing the input selection for a new measurement requires switching between inputs at different voltage levels. The input
interface circuits of the ADC, together with the externally added noise-rejection filters (if applicable), require a settling time
to reach the new voltage value with a 10-bit accuracy (less than 1/2 LSB error). Therefore, the ADC waits for a programma-
ble delay time between the selection of the input to be measured and the beginning of the A/D conversion. This Voltage
Channel Delay is expressed in ADC clock cycles in ADC Delay Control register (ADLYCTL). The number of ADC clock cy-
cles should be converted to time using the following formula:
tVD = Number_of_ADC_clocks *(System_clock_cycle) *SCLKDIV(5-0)
To calculate the required delay value according to externally added components, see Section 4.11.7 on page 185.
4.11.4 Temperature Measurement
TheADC performs a linear conversion of the temperature, measured by a remote or alocal diode, to an 8-bit, 2s complement
digital representation. The ADC generates a current that flows through the diode and measures the resulting voltage drop.
This differential voltage is converted to an 8-bit value, with the LSB equal to 1°C, according to Table 22.
Input Channel Scale Calculation1
1. See Section 7.4.1 on page 378 for the dynamic range relevant for each input.
AD0 to AD9 Low Vi = VCHDAT(9-0) * (1 / 1024) * VFSL
AD0 to AD9 High Vi = VCHDAT(9-0) * (1 / 1024) * VFSH
AD10 to AD13 Low2,3
2. High Scale is undefined for these inputs.
3. These inputs are scaled down by 4 at the input and compensated back at the result read phase.
Vi = VCHDAT(9-0) * (1 / 1024) * VFSV
Table 22. Temperature Format Conversion
Temperature
(°C)
Temperature Channel Data
Binary Hex
+1271
1. Values higher than +125°C and lower than 40°C
are not within the specified operating temperature range.
0111 1111 7F16
+125 0111 1101 7D16
+100 0110 0100 6416
+40 0010 1000 2816
+25 0001 1001 1916
+1 0000 0001 0116
0 0000 0000 0016
1 1111 1111 FF16
25 1110 0111 E716
40 1101 1000 D816
12811000 0000 8016
Embedded Controller Modules (Continued)
www.national.com 174 Revision1.07
PC87591E/S/L
To change the diode selection for a new measurement, the input is switched between inputs at different voltage levels. The
temperature input interface circuits of the ADC require a settling time to reach the new voltage value with the equivalent of
1/2°C accuracy. Therefore, the ADC waits for a programmable delay time between the selection of the diode to be measured
and the beginning of the A/D conversion. This Temperature Channel Delay is expressed in ADC clock cycles in ADC Delay
Control register (ADLYCTL). The number of ADC clock cycles should be converted to time using the following formula:
Delay = Number_of_ADC_clocks *(System_clock_cycle) *SCLKDIV(5-0)
To calculate the required delay value according to the externally added components, see Section 4.11.7 on page 185.
4.11.5 ADC Operation
Reset
Section 3.2 on page 65 describes the types of PC87591x resets. The ADC is affected by the core domain reset events, as
described below:
All control, configuration and status registers are reset to their default values, as indicated in Section 4.11.6 on page 177.
An exception to this is OTSEV (Overtemperature Event) bit in ADCSTS register, which is reset at VCC Power-Up reset only.
The Temperature and Voltage (1, 2 and 3) Channel Data Buffer registers are not reset, since their value is undefined until
the first measurement occurs (on each of them).
The ADC is disabled, with all interrupt sources masked and all event status bits reset. The remote temperature diode is dis-
abled, and the voltage inputs AD8 and AD9 may be used. The clock division factor, as well as the temperature channel delay
and the voltage channel delay, are all set to their maximum value (for the slowest ADC operation speed). The Overtemper-
ature limit is set to the highest value (127°C) for maximum flexibility. Each of the four channels is individually disabled, along
with its interrupt source. The Selected Input for all three voltage channels is set to 1F16 (disabled).
ADC Clock
The ADC clock is generated by dividing the system clock by a factor in the range of 4 to 63, as defined in SCLKDIV field in
ACLKCTL register (see Section 4.11.6 on page 177). The system clock’s source is the on-chip clock multiplier (see
Section 4.18 on page 239). The ADC clock needs to be at a frequency of 0.5 MHz. SCLKDIV must be programed prior to
enabling the ADC (i.e., while ADCEN of the ADCCNF register is 0).
Initializing the ADC
The ADC must be initialized before it is enabled. The following steps need to be taken to initialize it before enabling the ADC
(i.e., ADCEN bit in ADCCNF register is cleared):
System Clock Division Factor - SCLKDIV field in ACLKCTL register.
Temperature Channel Delay - TMPDLY field in ADLYCTL register.
Voltage Channel Delay - VOLDLY field in ADLYCTL register.
Select use of Remote Diode or AI8 and AI9 - REMDEN bit in ADCCNF register.
Copy calibration information from the flash to the index-data fields using the following sequence:
a. Read a byte from flash information block.
b. Set index for that parameter in ADCPINX register.
c. Write data to ADCPD register.
d. Repeat steps a-c for all parameters, as defined in Section B.1 on page 434.
e. Select index 00h in ADCPINX and write data of 0116 to ADCPD to lock the calibration information.
Enabling and Disabling the ADC
Enabling the ADC. The ADC is enabled by setting ADCEN in ADCCNF register to 1.
After the ADC is enabled, its internal circuits need an activation delay of 100 µs. This activation delay should be added to
the ADC cycle until the first batch of measurements (after enabling the ADC) is available. Note that after activation, the first
set of results using the large scale mode (CSCALE bit in VCHiCTL register is clear) may be wrong.
The PC87591x temperature is measured as long as the ADC is active. Other measurement operations may be enabled or
disabled individually. When measurement conversions are enabled while the ADC is enabled, the measurement operations
start on the following conversion cycle.
Disabling the ADC. The ADC is disabled by resetting ADCEN in ADCCNF register when one of these conditions applies:
VCC Power-Up reset
Warm reset
Core enters Idle mode
The software resets the ADCEN bit.
Embedded Controller Modules (Continued)
Revision 1.07 175 www.national.com
PC87591E/S/L
In this state, all ADC activities are halted and ADC current consumption from the AVCC is reduced. Note that re-enabling the
ADC causes an activation delay.
It is recommended to disable the ADC only after the buffer registers of all four channels have been read.
Interrupt Structure
The ADC Interrupt is a level high interrupt, generated if one (or more) of the events in Table 23 becomes active. The ADC
interrupt is connected to the ICU.
When an event flag and its related mask bit are set (enabled), the ADC Interrupt request is asserted. This is indicated by
a high level of the ADC Interrupt signal.
The software must reset the event flag (or reset its mask bit) in order to deassert the ADC Interrupt request.
All the interrupt mask bits (interrupt disabled), the data-related event flags (EOCEV and the four DATVAL bits) and the con-
nection-failure event flag (OPSHEV) are cleared by both reset conditions. The overtemperature event flag (OTSEV) is
cleared only by VCC Power-Up Reset.
The ADC Interrupt is routed to the ICU as an ADCI signal (see Section 4.3 on page 98).
ADC Operating Principles
Measurement Sequence. The following measurements are executed, in the order listed, during one ADC cycle for all en-
abled channels:
1. Temperature measurement, from the input indicated by SELIN field in TCHANCTL register. The A/D conversion starts
by selecting the input and waiting for the time period (TMPDLY delay) set in ADLYCTL register. The resulting 8-bit digital
value is stored in TCHANDAT register, and DATVAL bit in TCHANCTL register is set.
2. Voltage measurement for Voltage Channel 1, from the input selected by SELIN field in VCHN1CTL register. The A/D
conversion starts by selecting the input and waiting for the time period (VOLDLY delay) set in ADLYCTL register. The
resulting 10-bit digital value is stored in VCHN1DAT register, and DATVAL bit in VCHN1CTL register is set. Note: This
measurement is skipped if Voltage Channel 1 is disabled by setting the SELIN field in VCHN1CTL register to 1F16.
3. Voltage measurement for Voltage Channel 2, as above, using the VCHN2CTL and VCHN2DAT registers.
4. Voltage measurement for Voltage Channel 3, as above, using the VCHN3CTL and VCHN3DAT registers.
5. End of the ADC cycle. EOCEV bit in ADCSTS register is set (in addition to all the relevant DATVAL bits).
The software may read the measurement result for each channel immediately after its DATVAL bit is set. Alternatively, the
results may be read at the end of the cycle when EOCEV bit is set. After the data in VCHNiDAT register is read, the software
should clear the relevant DATVAL bit to indicate that the data in the buffers has been read.
The ADC cycle duration may be calculated using the formula below (N is the number of enabled voltage channels):
TADC cycle =2*(tTD +t
TC) + (N+1) *(tVD +t
VC)
Where:tTD - Temperature Conversion Delay Time
tTC - Temperature Conversion Time
tVD - Voltage Conversion Delay Time
tVC - Voltage Conversion time
Table 23. ADC Interrupt Structure
Event Flag Register
Mnemonic Mask Bit Register
Mnemonic Description
OPSHEV ADCSTS INTOSEN ADCCNF Open/Short Event/Enable
OTSEV ADCSTS INTOTEN ADCCNF Overtemperature Event/Enable
EOCEV ADCSTS INTECEN ADCCNF End-of-Cycle Event/Enable
DATVAL TCHANCTL INTDVEN TCHANCTL Data Valid Event/Enable (Temperature Channel)
DATVAL VCHN1CTL INTDVEN VCHN1CTL Data Valid Event/Enable (Voltage Channel 1)
DATVAL VCHN2CTL INTDVEN VCHN2CTL Data Valid Event/Enable (Voltage Channel 2)
DATVAL VCHN3CTL INTDVEN VCHN3CTL Data Valid Event/Enable (Voltage Channel 3)
Embedded Controller Modules (Continued)
www.national.com 176 Revision1.07
PC87591E/S/L
See Section 7.4 on page 378 for the values of tTC, Section 4.11.4 on page 173 for tTD calculation and Section Section 4.11.3
on page 173 for tVC calculation.
Temperature inputs from remote and local diodes are measured by alternating the remote and local diodes in each succes-
sive ADC cycle. If the remote diode measurement is disabled (RDMEASEN is set to 0 in TCHANCTL register or REMDEN
in ADCCNF register is set to 0), the local diode temperature is measured every ADC cycle.
Input Selection Field. Each Voltage Channel has its own programmable, input selection field (SELIN in VCHNxCTL regis-
ter). This field determines which input is measured by the channel during the current ADC cycle. The field also indicates to
which input the data in the channel buffer belongs. This field may be modified after the channel buffer has been read and
the DATVAL bit has been reset.
If the input selection field is not changed, the same input is measured during the next ADC cycle. This gives a sampling rate
of one TADC cycle for the specific input. If this field is changed and a different input is sampled, the sampling rate is lower for
each input, but the period for all scanned inputs is shorter.
Operation Sequence. After the ADC is properly initialized and enabled, one of the following example sequences can be used:
EOCEV-driven ADC operation sequence for all temperature and voltage channels
DATVAL-driven ADC operation sequence for one temperature or voltage channel
EOCEV-Driven ADC Operation Sequence for All Channels
1. When End-of-Cycle is reached (i.e., after all enabled channel conversions are completed), software can detect the event
by waiting for EOCEV bit in ADCSTS register to be set to 1.
2. Read the input number of the temperature channel by reading SELIN in TCHANCTL register.
3. Read the temperature value measured by reading TCHDAT in TCHANDAT register.
4. In preparation for the next measurement, clear DATVAL bit in TCHANCTL register by writing 1 to it.
5. Measure the input number for Voltage Channel 1 by reading SELIN in VCHN1CTL register.
6. Read the number of input measured in Voltage Channel 1 by reading VCHDAT in VCHN1DAT register.
7. In preparation for the next measurement (i.e., to define which input will be measured by Voltage Channel 1 during the
next ADC cycle), clear DATVAL bit in VCHN1CTL register by writing 1 to it (it may be the same input or, optionally, a different
one).
8. For Voltage Channel 2, repeat steps 5 through 7 for the VCHN2CTL and VCHN2DAT registers.
9. For Voltage Channel 3, repeat steps 5 through 7 for the VCHN3CTL and VCHN3DAT registers.
DATVAL-Driven ADC Operation Sequence for One Channel
1. Measure the end of channel by waiting for DATVAL in TCHANCTL or VCHNxCTL register to be set to 1.
2. Measure the input number by reading SELIN in TCHANCTL or VCHNxCTL register.
3. Read the measured data by reading TCHDAT or VCHDAT in TCHANDAT or VCHNxDAT register, respectively.
4. Optional (for voltage channels only): Change the input to be measured during the next ADC cycle: in VCHNxCTL regis-
ter, write a new SELIN value.
5. Prepare the temperature or voltage channel to receive new data: in TCHANCTL or VCHNxCTL register, write 1 to
DATVAL to clear it.
6. In preparation for the next measurement (i.e., to define which input will be measured by the temperature channel or the
voltage channel during the next ADC cycle), clear the DATVAL bit by writing 1 to it (it may be the same input or, option-
ally, a different one).
Reading Measurement Results
Polling-Driven Operation. Measurement results may be read by polling either EOCEV in ADCSTS register or each of the
four DATVAL bits in TCHANCTL register and three VCHNxCTL registers.
Polling EOCEV uses the sequence listed in “EOCEV-Driven ADC Operation Sequence for All Channels”, above. When
EOCEV is set, all four channels contain valid data and may be read.
Polling DATVAL uses the sequence listed in “DATVAL-Driven ADC Operation Sequence for One Channel”, above. When a
DATVAL bit is set, only its channel contains valid data that may be read. In this case, the EOCEV bit is redundant.
Interrupt-Driven Operation. The ADC may generate an interrupt to the core when any of the valid bits is set (EOCEV in
ADCSTSregisterorDATVAL in either TCHANCTL or any VCHNxCTL register). Theinterrupt is generated when the interrupt
enable bit for the respective status bit is set. The software in the interrupt routine should check the status bits as described
above for polling-driven operation to verify which of the DATVAL bits is set.
Embedded Controller Modules (Continued)
Revision 1.07 177 www.national.com
PC87591E/S/L
An interrupt is expected from EOCEV when using the sequence listed in the EOCEV-driven ADC operation sequence (see
above). The EOCEV interrupt indicates that all four channels contain valid data and may be read. Interrupts from the
DATVAL bits should be disabled.
An interrupt is expected from one of the DATVAL bits when using the sequence listed in the DATVAL-driven ADC operation
sequence (see above). The DATVAL interrupt indicates that only its channel contains valid data that may be read. Interrupts
from the EOCEV bit should be disabled.
Failure Detection
Open/Short. At the beginning of the temperature measurement from the remote diode, the Temperature Sensor Interface
checks the condition of the interconnection (shorted or disconnected cable) and updates OPSHTYPE and OPSHEV in
ADCSTS register (see Section 4.11.6 on page 177). Although the measurement is executed and the DATVAL bit in
TCHANCTL register is set, the contents of the data buffer (TCHANDAT) should be ignored.
Overtemperature. At the end of the temperature measurement from the local diode (after DATVAL bit in TCHANCTL reg-
ister is set), the ADC compares the measured temperature with the limit value set by OTSLIM in TLOCOTL register. When-
ever the measured temperature is higher than the limit value, OTSEV in ADCSTS register is set and an active low OTS signal
is issued.
Overflow. An overflow occurs when DATVAL bit in TCHANCTL register is set at the end of a measurement, indicating that
the result of the previous measurement was not read. If an overflow occurs in at least one channel, the new measurement
result overrides the old data in the buffer, and OVFEV in ADCSTS register is set. This indicates that the result of the previous
measurement was lost.
4.11.6 ADC Registers
The ADC control/status and data out registers set interfaces with the core through the Peripheral bus. These registers are
mapped in the address space of the core, starting at the base address defined in Section B.1 on page 434.
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
ADC Register Map
The ADC register set contains seven common, control and status registers and eight channel-specific registers.
Table 24. ADC Register Map
Mnemonic Register Name Type
ADCSTS ADC Status Varies per bit
ADCCNF ADC Configuration R/W
ACLKCTL ADC Clock Control R/W
ADLYCTL ADC Delay Control R/W
TLOCOTL Local Diode Overtemperature Limit R/W
ADCPINX ADC Parameters Index R/W
ADCPD ADC Parameters Data R/W
TCHANCTL Temperature Channel Control Varies per bit
TCHANDAT Temperature Channel Data Buffer RO
VCHN1CTL Voltage Channel 1 Control Varies per bit
VCHN1DAT Voltage Channel 1 Data Buffer RO
VCHN2CTL Voltage Channel 2 Control Varies per bit
VCHN2DAT Voltage Channel 2 Data Buffer RO
VCHN3CTL Voltage Channel 3 Control Varies per bit
VCHN3DAT Voltage Channel 3 Data Buffer RO
Embedded Controller Modules (Continued)
www.national.com 178 Revision1.07
PC87591E/S/L
ADC Status Register (ADCSTS)
This register indicates the global status of the ADC module. ADCSTS is cleared (0016)onV
CC Power-Up reset; on other
resets, bit 2 is unchanged and other bits are cleared.
Location: 00 FF2016
Type: Varies per bit
Bit 76543210
Name Reserved OPSHTYPE OPSHEV OTSEV OVFEV EOCEV
Warm Reset 00000-00
Power-Up
Reset 00000000
Bit Type Description
0ROEOCEV (End-of-Cycle Event). End of ADC cycle; all enabled measurements (up to four) are
completed. For each of the enabled channels, the DATVAL bit in the respective TCHANCTL VCHNxCTL
register is set, and the data for the channel is stored in the respective Channel Data Buffer register.
0: Cycle in progress (default)
1: End of ADC cycle (the bit remains set until all DATVAL bits in the Channel Control registers are reset)
1 R/W1C OVFEV (Data Overflow Event). Measurement data from the previous cycle was overwritten with data
from the current cycle before being read. In the event of a data overflow, the DATVAL bit remains set
and new data is placed in Channel Data Buffer register.
0: No overflow (default)
1: Overflow
2 R/W1C OTSEV (Overtemperature Signal Event). Temperature measured by local diode exceeded the limit.
0: Temperature below or equal to the limit (VCC Power-up reset default)
1: Temperature above limit (once set, this bit is cleared by writing 1 to it; writing 0 is ignored)
3 R/W1C OPSHEV (Open/Short Event). Remote diode connection failure (cable shorted or disconnected).
Checked before the beginning of the remote diode temperature measurement (if enabled, REMDEN in
ADCCNF register and RDMEASEN in TCHANCTL register are set to 1).
0: No fault was detected (default)
1: Connection failure - the cable was shorted or disconnected (once set, this bit is cleared by writing 1 to
it; writing 0 is ignored)
4ROOPSHTYPE (Open or Short Type). Remote diode connection failure type. Indicates the type of error
flagged by OPSHEV.
0: DP shorted to DN or to AGND (default)
1: DP disconnected (floating) or shorted to AVCC
7-5 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 179 www.national.com
PC87591E/S/L
ADC Configuration Register (ADCCNF)
This register controls the operation and global configuration of the ADC module. ADCCNF is cleared (0016) on reset.
Location: 00 FF2216
Type: R/W
ADC Clock Control Register (ACLKCTL)
This register controls the system clock to ADC clock division. ACLKCTL is set to 3F16 on reset.
Location: 00 FF2416
Type: R/W
Bit 76543210
Name Reserved INTOSEN INTOTEN INTECEN REMDEN ADCEN
Reset 00000000
Bit Description
0ADCEN (ADC Module Enable). Controls the operation of the ADC to minimize power consumption and prevent
glitch effects during configuration changes; see “Enabling and Disabling the ADC” on page 174.
0: ADC disabled (default)
1: ADC enabled
1REMDEN (Remote Temperature Diode Enable). Controls the utilization of the package pins for either the
remote diode (DP, DN) or the AI8 and AI9 voltage inputs (AD8, AD9).
0: AI8, AI9 voltage inputs enabled (default) - forces RDMEASEN in TCHANCTL register to 0; only the local diode
is measured by the temperature channel.
1: Remote diode enabled - if RDMEASEN in TCHANCTL register is set, the temperature channel measures both
the remote and the local diodes in successive cycles.
2INTECEN (Interrupt from End-of-Cycle Event Enable). Enables generation of an ADC interrupt on an End-of
ADC-cycle event (EOCEV in ADCSTS register).
0: Disabled (default)
1: Enabled - ADC Interrupt from EOCEV
3INTOTEN (Interrupt from Overtemperature Event Enable). Enables generation of an ADC interrupt on an
Overtemperature event (OTSEV in ADCSTS register).
0: Disabled (default)
1: Enabled - ADC Interrupt from OTSEV
4INTOSEN (Interrupt from Open/Short Event Enable). Enables generation of an ADC interrupt on an
Open/Short event (OPSHEV in ADCSTS register).
0: Disabled (default)
1: Enabled - ADC Interrupt from OPSHEV
7-5 Reserved.
Bit 76543210
Name Reserved SCLKDIV
Reset 00111111
Bit Description
5-0 SCLKDIV (System Clock Division Factor). Used to divide the system clock in order to obtain the ADC clock.
The system clock frequency is set separately (see Figure 78 on page 239). The resulting ADC clock frequency
should be equal to 0.5 MHz.
Range: 4 to 63 (default is 63, decimal values); values 0 to 3 are illegal and may result in undetermined ADC behavior.
7-6 Reserved.
Embedded Controller Modules (Continued)
www.national.com 180 Revision1.07
PC87591E/S/L
ADC Delay Control Register (ADLYCTL)
This register controls the delay between “input switching” and “conversion start” for the voltage and temperature channels.
ADLYCTL is set to A716 on reset.
Location: 00 FF2616
Type: R/W
Bit 76543210
Name TMPDLY Reserved VOLDLY
Reset 10100111
Bit Description
2-0 VOLDLY (Voltage Channel Delay). Compensates for the settling time of the input interface and externally added
filter (if used). The conversion of the VOLDLY value to delay, in terms of ADC clock cycles, is shown below. To
calculate the required value and the resulting delay time, see Section 4.11.3 on page 173 and “Calculating the
Voltage Channel Delay” on page 186.
VOLDLY Value
Bits
2 1 0: Voltage Channel Delay (ADC Clock Cycles)
0 0 1: 4
0 1 0: 8
0 1 1: 16
1 0 0: 32
1 0 1: 64
1 1 0: 128
1 1 1: 256 (default)
Other: Reserved
3Reserved.
7-4 TMPDLY (Temperature Channel Delay). Compensates for the settling time of the input interface and externally
added filter (if used). The conversion of the TMPDLY value to delay, in terms of ADC clock cycles, is shown
below. To calculate the required value and the resulting delay time, see Section 4.11.4 on page 173 and
“Calculating the Temperature Channel Delay” on page 188.
TMPDLY Value
Bits
7 6 5 4 Temperature Channel Delay (ADC Clock Cycles)
0 0 0 1: 32
0 0 1 0: 64
0 0 1 1: 128
0 1 0 0: 256
0 1 0 1: 512
0 1 1 0: 1024
0 1 1 1: 2048
1 0 0 0: 4096
1 0 0 1: 8192
1 0 1 0: 16384 (default)
Other: Reserved
Embedded Controller Modules (Continued)
Revision 1.07 181 www.national.com
PC87591E/S/L
Local Diode Overtemperature Limit Register (TLOCOTL)
This register holds the limit value used for overtemperature detection. TLOCOTL is set to 7F16 on reset.
Location: 00 FF2816
Type: R/W
ADC Parameters Index Register (ADCPINX)
This register holds an index to the ADC parameters registers. Use it while initializing the ADC (see “Initializing the ADC” on
page 174 for more details). ADCPINX is cleared (0016) on reset.
Location: 00 FF2A16
Type: R/W
ADC Parameters Data Register (ADCPD)
This register enables access to the ADC parameters registers. Use it while initializing the ADC (see “Initializing the ADC” on
page 174 for more details).
Location: 00 FF2C16
Type: R/W
Bit 76543210
Name OTSLIM
Reset 01111111
Bit Description
7-0 OTSLIM (Overtemperature Limit Value). Threshold value for Overtemperature Event detection. Whenever the
temperature measured by the local (internal) diode exceeds this limit, the OTSEV bit is set, an interrupt is sent
to the core (if INTOTEN in ADCCNF register is set to 1) and the OTS signal becomes active. To calculate the
required value for a specific temperature limit, see Section 4.11.4 on page 173.
Range: 128 to +127 (default is +127; these are decimal values); 8-bit, 2s complement value with 1 LSB = 1oC.
Bit 76543210
Name Index
Reset 00000000
Bit Description
7-0 Index. Defines which parameter register is being accessed by the ADCPD register.
Bit 1514131211109876543210
Name Parameter Data
Bit Description
15-0 Parameter Data. The register is used to access the ADC parameters register that the Index register (ADCPINX)
points to.
Writing 0116 to index 0016 locks the parameter data registers from any further writes until the next reset.
Embedded Controller Modules (Continued)
www.national.com 182 Revision1.07
PC87591E/S/L
Temperature Channel Control Register (TCHANCTL)
This register both controls the operation and indicates the status of the Temperature channel. TCHANCTL is set to 1016 on
reset.
Location: 00 FF3016
Type: Varies per bit
Temperature Channel Data Buffer (TCHANDAT)
This register (buffer) holds the data measured by the Temperature Channel.
Location: 00 FF3216
Type: RO
Bit 76543210
Name DATVAL RDMEASEN INTDVEN SELIN
Reset 00010000
Bit Type Description
4-0 RO SELIN (Selected Input). Indicates which temperature input was selected for measurement. If
RDMEASEN is set to 0, only the value 16 dec is read.
Bits
4 3 2 1 0 Description
0 1 1 1 1: Remote diode (DP, DN pins) selected
1 0 0 0 0: Local diode (internal) selected (default)
5 R/W INTDVEN (Interrupt from Data Valid Enable). Temperature channel, Data Valid event (End-of-
conversion) enabled to the ADC Interrupt.
0: Disabled (default)
1: Enabled - ADC Interrupt from local DATVAL
6 R/W RDMEASEN (Remote Diode Measurement Enable). Enables the temperature measurement using the
remote diode (REMDEN in ADCCNF register is set to 1). Using only the local diode enables a higher
measurement rate for the internal temperature. The temperature channel cannot be disabled
(“skipped”) since the internal temperature measurement is required.
0: Measurement disabled - only the local diode is measured by the temperature channel; forced into this
state when REMDEN in ADCCNF register is set to 0 (default).
1: Measurement enabled - the temperature channel measures both the remote and the local diodes in
successive cycles; possible only if REMDEN is set to 1.
7 R/W1C DATVAL (Data Valid). The Temperature Channel Data Buffer contains new data. The data may be read
immediately or at the end-of-cycle. This flag is cleared when the ADC module is disabled (ADCEN in
ADCCNF register is cleared) or by writing 1 to it.
0: No valid data in TCHANDAT register (default)
1: End of conversion - new data is available in TCHANDAT
Bit 76543210
Name TCHDAT
Bit Description
7-0 TCHDAT (Temperature Channel Data). Temperature of either the remote or local diode, measured by the
Temperature Channel. For the temperature word format, see Section 4.11.4 on page 173. The data is valid and
may be read only at the end of the conversion, when DATVAL in TCHANCTL register is set to 1. DATVAL must
be reset after reading the data.
Range: 128 to +127 (values are decimal); 8-bit, 2s complement value with 1 LSB = 1oC (the value at reset is
undefined).
Embedded Controller Modules (Continued)
Revision 1.07 183 www.national.com
PC87591E/S/L
Voltage Channel 1 Control Register (VCHN1CTL)
This register both controls the operation and indicates the status of Voltage Channel 1. VCHN1CTL is set to 1F16 on reset.
Location: 00 FF3416
Type: Varies per bit
Bit 76543210
Name DATVAL CSCALE INTDVEN SELIN
Reset 00011111
Bit Type Description
4-0 R/W SELIN (Selected Input). Selects a voltage input to be measured during the next ADC cycle. The new
value should be set before the beginning of the channel measurement. When read, this field indicates
to which input the contents of the channel data buffer belongs. When written, it selects a new input for
the next channel measurement. See Figure 60 on page 172 for details on the channel input signals
connection to pins.
The channel is disabled by setting this field to 111112. When disabled, the channel is “skipped”,
enabling a higher measurement rate for the remaining channels (shorter ADC cycle). The DATVAL bit
is cleared
Bits
4 3 2 1 0 Description
0 0 0 0 0: Channel 0
0 0 0 0 1: Channel 1
....
0 1 0 0 0: Channel 8 (Available when REMDEN bit in ADCCNF register is cleared)
0 1 0 0 1: Channel 9 (Available when REMDEN bit in ADCCNF register is cleared)
0 1 0 1 0: Channel 10
....
0 1 1 0 1: Channel 13
Other: Reserved
1 1 1 1 1: Channel Disabled (default)
5 R/W INTDVEN (Interrupt from Data Valid Enable). Enables generation of an ADC interrupt on a Voltage
Channel 1, Data Valid event (End-of-conversion).
0: Disabled (default)
1: Enabled - ADC Interrupt from local DATVAL
6 R/W CSCALE (Channel Scale). Controls the input scale of the input for the channel to be converted (as
selected by SELIN field).
0: Channel uses the high range scale (default)
1: Channel uses the low range scale
7 R/W1C DATVAL (Data Valid). Voltage Channel 1 Data Buffer contains new data. The data may be read
immediately or at the end-of-cycle. This flag is cleared when the channel is disabled, when the ADC
module is disabled (ADCEN in ADCCNF register is cleared) or by a write of 1 to it.
0: No new valid data in VCHN1DAT register (default)
1: End of conversion - new data is available in the buffer
Embedded Controller Modules (Continued)
www.national.com 184 Revision1.07
PC87591E/S/L
Voltage Channel 1 Data Buffer (VCHN1DAT)
This register (buffer) holds the data measured by Voltage Channel 1.
Location: 00 FF3616
Type: RO
Voltage Channel 2 Control Register (VCHN2CTL)
This register controls the operation and indicates the status of Voltage Channel 2. VCHN2CTL is set to 1F16 on reset.
Location: 00 FF3816
Type: Varies per bit
Voltage Channel 2 Data Buffer (VCHN2DAT)
This register (buffer) holds the data measured by the Voltage Channel 2.
Location: 00 FF3A16
Type: RO
Bit 1514131211109876543210
Name Reserved VCHDAT
Bit Description
9-0 VCHDAT (Voltage Channel 1 Data). Selected input voltage data, measured by Voltage Channel 1. To calculate
the voltage, see Section 4.11.3 on page 173. VCHN1DAT holds valid result when DATVAL bit in VCHN1CTL
register is set. To prepare for consecutive result, clear DAVAL after reading the data from VCHDAT.
Range: 0 to 1023 (0 to VFS); 10-bit, unsigned value with 1 LSB = VFS/1024 (the value at reset is undefined).
15-10 Reserved.
Bit 76543210
Name DATVAL CSCALE INTDVEN SELIN
Reset 00011111
Bit Type Description
4-0 R/W SELIN (Selected Input). Same as Voltage Channel 1.
5 R/W INTDVEN (Interrupt from Data Valid Enable). Same as Voltage Channel 1.
6 R/W CSCALE (Channel Scale). Same as Voltage Channel 1.
7 R/W1C DATVAL (Data Valid). Same as Voltage Channel 1.
Bit 1514131211109876543210
Name Reserved VCHDAT
Bit Description
9-0 VCHDAT (Voltage Channel 2 Data). Same as Voltage Channel 1.
15-10 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 185 www.national.com
PC87591E/S/L
Voltage Channel 3 Control Register (VCHN3CTL)
This register controls the operation and indicates the status of Voltage Channel 3. VCHN3CTL is set to 1F16 on reset.
Location: 00 FF3C16
Type: Varies per bit
Voltage Channel 3 Data Buffer (VCHN3DAT)
This register (buffer) holds the data measured by Voltage Channel 3.
Location: 00 FF3E16
Type: RO
4.11.7 Usage Hints
Power Supply and Layout Guidelines
For more information, see Section 3.1.3 on page 63.
Power Consumption
ADC power consumption from the analog supply (AVCC) is practically zero if the ADC is disabled by setting ADCEN in
ADCCNF register to 0.
When the ADC is enabled, the current consumption depends on the channel type measured (voltage or temperature) and
the ADC clock frequency. To minimize current consumption, disable the ADC when not in use. See details in “Enabling and
Disabling the ADC” on page 174.
Back-Drive Protection
To maintain the high performance of the analog circuits, AD(0-7), AD8/DP and AD9/DN pins are not back-drive protected.
Therefore, the voltage applied to these pins must be within the AGND to AVCC range; otherwise, the device may be dam-
aged. External circuits should not drive currents into these pins when the PC87591x is not powered up.
Measuring Out of Range Voltages
The ADC is capable of measuring positive input voltages from 0V to VFS. Input voltages outside this range should either be
divided or level-shifted, as required.
Bit 76543210
Name DATVAL CSCALE INTDVEN SELIN
Reset 00011111
Bit Type Description
4-0 R/W SELIN (Selected Input). Same as Voltage Channel 1.
5 R/W INTDVEN (Interrupt from Data Valid Enable). Same as Voltage Channel 1.
6 R/W CSCALE (Channel Scale). Same as Voltage Channel 1.
7 R/W1C DATVAL (Data Valid). Same as Voltage Channel 1.
Bit 1514131211109876543210
Name Reserved VCHDAT
Bit Description
9-0 VCHDAT (Voltage Channel 3 Data). Same as Voltage Channel 1.
15-10 Reserved.
Embedded Controller Modules (Continued)
www.national.com 186 Revision1.07
PC87591E/S/L
For positive input voltages higher than VFS, a resistor divider should be used in front of the analog input (see Figure 61a).
The divider should be calculated so that its output is lower than the full-scale value (VFS) for the maximum input signal
voltage.
For negative input voltages, a resistive level-shifter should be used in front of the analog input (see Figure 61b). The level-
shifter should be calculated so that its output is higher than 0V for the minimum input signal voltage.
Filtering the Noise on Voltage Input Signals
Noise may be coupled to the input signal for various reasons, including close proximity to digital circuits. The slow change
rate of the input signals, makes it possible to use an external low pass filter (LPF). This can be implemented by placing a
capacitor (CF) between the divider output and AGND, as shown in Figure 61. The cutoff frequency of this LPF should be at
least 22 times the maximum signal frequency required to be measured with a 10-bit accuracy (a smaller capacitor may be
used when a lower accuracy is acceptable). The formula below demonstrates the calculation of the components.
f(-3dB) =1/(2*π*Req*CF)
where: Req = (R1*
R2) / (R1 + R2)
Calculating the Voltage Channel Delay
The Voltage measurement delay time (tVD) is the period between input selection and the A/D conversion start. This delay
should be long enough to guarantee the voltage settling at the input of the A/D converter to within 1/2 LSB. This includes
the input interface circuits of the ADC and the externally added noise-rejection filters (if applicable). Figure 62 shows the
equivalent R-C circuit of a filtered input. Req represents the equivalent resistance of the input divider or level-shifter (see the
preceding section, “Filtering the Noise on Voltage Input Signals”). CFis the filter capacitor. The Input Interface Circuit in-
cludes the input the multiplexer.
Since the R-C of the input circuit is short, typically, all that is required is a very short delay, which shortens the overall mea-
surement time. The delay length may be sized during development by increasing the delay time from the minimum value to
the point were the ADC readout is not affected by the delay value (i.e., use the minimal delay to which the ADC readout is
invariant).
.
Thermistor-Based Temperature Measurement
The ADC is capable of measuring temperature by means of NTC or PTC thermistor devices. These elements change their
resistance according to their temperature. The resistance change is converted to voltage by connecting the element in a
voltage divider between AVCC and AGND, as shown in Figure 63. The translation of voltage to temperature is determined
by the parameters of the NTC/PTC thermistor in use.
R1
VIN (12V)
R
2
ADn
R1
R
2
ADn
VIN (-12V)
AVCC
AGND AGND
Figure 61. Measurement of Positive and Negative Voltages
a. VIN > VFS b. VIN < 0
C
F
C
F
Input
Signal
Figure 62. Filtered Voltage Input Equivalent Circuit
Interface
ADn
Circuit
Req
VIN CF
Input A/D Converter
Σ−∆
Embedded Controller Modules (Continued)
Revision 1.07 187 www.national.com
PC87591E/S/L
Remote Diode Selection
Temperature accuracy depends on a good quality transistor used as a diode-connected, small-signal transistor. Accuracy
has been experimentally verified for the devices, among them Motorola, listed in Table 25. A temperature sensor can directly
measure the die temperature of CPUs with on-board temperature-sensing diodes.
The transistor must be a small-signal type with a relatively high forward voltage; otherwise, the A/D input voltage range might
be violated. The forward voltage must be greater than 0.25V at 10 µA for the highest expected temperature. The forward
voltage must be less than 0.95V at 100 µA for the lowest expected temperature. Large power transistors do not work. Also,
ensure that the base resistance is less than 100. Tight specifications for forward-current gain (+50 to +150, for example)
indicate devices with consistent VBE characteristics.
Thermal mass can seriously degrade the temperature sensor’s effective accuracy. The use of smaller packages for remote
sensors, such as SOT23s, improves the situation.
Table 25. Remote Sensor Transistor Manufacturers
Filtering the Noise on Temperature Input Signals
Noise may be coupled to the input signal for various reasons, including close proximity to digital circuits. The ADC conver-
sion technology has good noise rejection especially for low-frequency signals, such as power supply hum. Rejection of high-
frequency noise can be improved using an external filter capacitor and PC board layout.
High-frequency noise is best filtered by placing a capacitor (CCof 2.2 nF) between pins DP and DN (see Figure 64), in prox-
imity to the PC87591x pins. The connection to the diode should use a twisted wire pair or a PCB that is read out using the
guidelines below.
It is most important to prevent any leak to ground, especially from the DP pin and serial resistance on the current loop to the
diode.
Manufacturer Model
Central Semiconductor (USA) CMPT3904
Motorola (USA) MMBT3904
National Semiconductor (USA) MMBT3904
Rohm Semiconductor (Japan) SST3904
Samsung (Korea) KST3904-TF
Siemens (Germany) SMBT3904
Zetex (England) FMMT3904CT-ND
R
NTC ADn
AVCC
AGND
Figure 63. Measuring Temperature Using Thermistors
a. NTC Thermistor b. PTC Thermistor
C
F
AVCC
PTC
R
ADn
AGND
C
F
Thermistor
T
o
T
o
Thermistor
Embedded Controller Modules (Continued)
www.national.com 188 Revision1.07
PC87591E/S/L
Calculating the Temperature Channel Delay
The delay time is the period between diode selection and the A/D conversion start. Due to the switched diode current, this
delay should be long enough to guarantee the voltage settling at the input of the A/D converter to within 0.5oC. This includes
the input interface circuits of the ADC and the externally added capacitors (CC).
It is preferable to use the minimal delay possible for the system. This depends on the capacitance on the wires and serial
resistance. TMPDLY field of ADLYCTL register defines the delay. Typically, a delay of 128 or 256 clocks (values 3 and 4,
respectively) is adequate. To find the best value, start from a high delay and reduce it until the point that the temperature
readouts starts to change. This parameter is mostly board layout and component dependent.
PC Board Layout
Place the PC87591x as close as practical to the remote diode. In a noisy environment, such as a computer moth-
erboard, this distance can be 4 in. to 8 in. (typical) or more, as long as the worst noise sources (such as CRTs, clock
generators, memory buses and ISA/PCI buses) are avoided.
Do not route the DP and DN lines next to high inductance signals. Also, do not route the traces across a fast memory
bus, which can easily introduce +30˚C error, even with good filtering. Otherwise, most noise sources are fairly benign.
Route the DP and DN traces in parallel and in close proximity to each other, away from any high voltage traces such
as +12V DC. Beware of leakage currents from PC board contamination; e.g., a 20 Mleakage path from DP to
ground causes about +1˚C error.
Connect guard traces to AGND on either side of the DP and DN traces (Figure 65). An additional AGND plane should
be placed “beneath” these traces. With guard traces and AGND plane in place, routing near high-voltage traces is no
longer a problem.
Route through as few vias and crossunders as possible to minimize copper/solder thermocouple effects.
When introducing a thermocouple, make sure that both the DP and DN paths have matching thermocouples.
In general, PC board-induced thermocouples are not a serious problem. A copper-solder thermocouple exhibits
3µV/˚C, and it takes about 200 µV of voltage error at DP and DN to cause a 1˚C measurement error. Therefore, most
parasitic thermocouple errors can be ignored.
Use wide traces. Narrow ones are more inductive and tend to pick up radiated noise. The 10 mil widths and spacings
recommended in Figure 65 are not absolutely necessary (as they offer only a minor improvement in leakage and
noise), but try to use them where practical.
2N3904
DP
DN
Twisted Wire Pair or
CC
Q1 PC87591x
CD= 2.2 to 3.3 nF
shielded PCB lines
Figure 64. Typical Remote Diode Circuit
Embedded Controller Modules (Continued)
Revision 1.07 189 www.national.com
PC87591E/S/L
Twisted Pair and Shielded Cables
Forremotesensordistanceslongerthan8inchesorinparticularly noisy environments, a twisted pair cable is recommended.
Its practical length is 6 feet to 12 feet (typical) before noise becomes a problem, as tested in a noisy electronics laboratory.
For longer distances, the best solution is a shielded twisted pair such as that used for audio microphones. Connect the twist-
ed pair to DP and DN and the shield to AGND close to the PC87591x, and leave the remote end of the shield unterminated.
For very long cable runs, the cable parasitic capacitance adds a delay to the Temperature Channel. You should add the
cable capacitance to the value of the CD(see “Calculating the Temperature Channel Delay” on page 188) and correct the
delay setting accordingly.
Cable resistance also affects remote sensor accuracy. A 1 series resistance introduces about +1.0˚C to +0.5˚C error.
AGND
10 mil
Minimum
10 mil
10 mil
10 mil
DP
DN
AGND
Figure 65. DP and DN, PCB Traces
Embedded Controller Modules (Continued)
www.national.com 190 Revision1.07
PC87591E/S/L
4.12 DIGITAL TO ANALOG CONVERTER (DAC)
The DAC converts digital input values to analog signals. The DAC support four channels for handling up to four independent
conversions in parallel.
4.12.1 Features
8-bit resolution
Independent 4-channel D/A converter
Fast settling time, 1 µs typical, on 50 pF capacitive load
Output range from AGND to AVCC
Independent enable/disable for each channel
All converters can be automatically disabled in Idle mode
Low power consumption when enabled; zero power consumption when disabled
Outputs drive 0V when disabled
4.12.2 Functional Description
The DAC has four independent digital-to-analog converters. Each converter generates an output in the range of 0V to AVCC,
with 8-bit resolution. The converters drive the four output pins DA0-3, as shown in Figure 67. An output impedance of 3 K
allows a settling time of about 1 µs on a 50 pF load.
When a DAC channel is enabled, its output is defined by the value written to its DACDATn register. DACDAT0-3 control
DA0-3, respectively. The maximum output voltage is (255 ÷256) *AVCC and is obtained for a value of FF16. The minimum
output, 0V, is obtained for a value of 0016.
The reference voltage of the converters is the AVCC analog power supply voltage. This allows full swing of the outputs from
0V to nearly AVCC.
After reset, all four channels are disabled and the voltage on the DA0-3 outputs is 0V.
In Idle mode, the DAC channels may be enabled or disabled (to reduce power consumption). Two control modes are pro-
vided:
Automatic disable of all channels on entering Idle mode
Selective disable of channels by software, before entering Idle mode
4.12.3 D/A Conversion
Output Signal
The DAC performs a linear conversion of the input digital value DACDATA7-0 registers to a unipolar analog output signal,
relative to the analog ground pin (AGND).
Embedded Controller Modules (Continued)
Revision 1.07 191 www.national.com
PC87591E/S/L
When the value of DACDATA7-0 is 0016, the respective output has an output signal of 0V (AGND). When the value of
DACDATn register is FF16, the respective output has an output signal of (255/256) *AVCC. For other values, as shown in
Figure 66:
VOUT = (DACDATAn) *(AVCC / 256)
Reference Voltage
The analog output voltages are converted relative to a reference voltage. The reference voltage of the converters is the an-
alog power supply. To assure good signal quality at the output, a low-noise analog power supply should be used.
Conversion Time
When a DAC channel is enabled, the conversion is started by writing to DACDATn registers. The output settling time is de-
fined as the time the DAC requires to get to within 1/2 LSB of the final value; see “Output Settling Time” on page 195.
0123(256)
255254
. . . .
0
1/256
2/256
3/256
254/256
255/256
1
. . . . .
Level Data
[LSBits]
Voltage Ratio to AVCC
Figure 66. Channel Data to Output Voltage Ratio Conversion
Embedded Controller Modules (Continued)
www.national.com 192 Revision1.07
PC87591E/S/L
4.12.4 Operation
Initializing the DAC
The PC87591x wakes up after power-up with all the D/A channels disabled (DACEN0-3 bits in DACCTRL register are
cleared to 0). In this state, all DAC activities are halted, and its current consumption is reduced to zero.
DACDATn registers (n=0 to 3) must be initialized to 0016, or according to the required output level, before setting DACEN0-3
in DACCTRL register to 1.
Enabling and Disabling the DAC
Enabling the DAC. Each channel of the DAC is enabled independently by setting its DACEN bit. After enabling, it settles to
the value stored in DACDATn register after the specified settling time.
Disabling the DAC. The DAC channels may be independently disabled in order to reduce current consumption by clearing
the corresponding DACENn (n=0 to 3) bit in DACCTRL register. In this case, the output pin drives 0V, even if the respective
DACDATn register does not contain 0016.
Figure 67. DAC Functional Diagram
DAC0 DA0
DA1
DA2
DA3
AVCC
AGND
DAC
DACDAT0
Analog
Power
AVCC
to other
modules
DAC
Control
Register
DAC1
DACDAT1
DAC2
DACDAT2
DAC3
VREF
DACDAT3
IDLE
AVCC
VREF
VREF
VREF
3.3V
Peripheral Bus
PC87591x
Embedded Controller Modules (Continued)
Revision 1.07 193 www.national.com
PC87591E/S/L
All DAC channels are automatically disabled when entering Idle mode if ENIDLE bit in DACCTRL register is cleared to 0.
This happens regardless of the state of DACENn (n=0 to 3) bit in DACCTRL register. In this case, the DA0-3 outputs drive
0V.
If the ENIDLE bit is set to 1, entering the Idle mode does not affect DAC operation, and DA0-3 outputs drive the voltage level
set by DACDATn (n=0 to 3) registers.
4.12.5 DAC Registers
The DAC interfaces with the core using one control and four data registers. These registers are mapped to the core address
space, as defined in Appendix A on page 408.
DAC Register Map
DAC Control Register (DACCTRL)
This register controls the operation of the DAC module. DACCTRL is cleared (0016) on reset.
Location: 00 FF4016
Type: R/W
Mnemonic Register Name Type
DACCTRL DAC Control R/W
DACDAT0 DAC Data Channel 0 R/W
DACDAT1 DAC Data Channel 1 R/W
DACDAT2 DAC Data Channel 2 R/W
DACDAT3 DAC Data Channel 3 R/W
Bit 76543210
Name Reserved ENIDLE DACEN3 DACEN2 DACEN1 DACEN0
Reset 00000000
Bit Description
0DACEN0 (DAC Channel 0 Enable). Enables the DAC channel. The DA0 output pin drives a voltage level,
according to the value written into the corresponding DACDAT0 register.
When cleared, the DA0 output pin drives 0V.
0: Disabled (default)
1: Enabled
1DACEN1 (DAC Channel 1 Enable). Same as DACEN0 bit description, using DA1 output and DACDAT1
register.
2DACEN2 (DAC Channel 2 Enable). Same as DACEN0 bit description, using DA2 output and DACDAT2
register.
3DACEN3 (DAC Channel 3 Enable). Same as DACEN0 bit description, using DA3 output and DACDAT3
register.
4ENIDLE (Enable in Idle). Controls the DAn (n=0 to 3) outputs in Idle mode.
0: Disabled - DAn outputs drive 0V (default)
1: Enabled - DAn outputs according to DACENn bits and DACDATn registers
7-5 Reserved.
Embedded Controller Modules (Continued)
www.national.com 194 Revision1.07
PC87591E/S/L
DAC Data Channel 0-3 Registers (DACDAT0-3)
These registers hold the data to be loaded into Channels 0-3 of the DAC. These registers are not affected by reset or disable
of the respective channel.
Location: Channel 0 - 00 FF4216
Channel 1 - 00 FF4416
Channel 2 - 00 FF4616
Channel 3 - 00 FF4816
Type: R/W
4.12.6 Usage Hints
Power Consumption
When a channel is enabled and no load is connected, the DAC current consumption depends on the value set in DACDAT
register. Minimal current is consumed when the data is 0016; maximum current is consumed when the data is 5516.
DAC Output Protection
To maintain the high performance of the analog circuits, the DAn (n=0 to 3) pins are not back-drive protected. Therefore, the
voltage applied to these pins must be within the AGND to AVCC range; otherwise the device may be damaged.
External circuits should not drive currents into these pins when the PC87591x is not powered up, because this may cause
the internal power-up reset circuit to fail.
Output Voltage Accuracy
Besides the intrinsic accuracy of the D/A channels, the output voltage accuracy directly depends on the accuracy of the
AVCC power supply, which serves as reference voltage. In order to improve the accuracy of the output voltage, the actual
AVCC value, measured by the ADC module (see Section 4.11 on page 170), should be used when computing the value of
DACDATA7-0 in DACDATn registers (see Section 4.12.3 on page 190).
The external load on DA0-3 pins may also affect the final output voltage of the DAC. Since the output resistance of these
pins is typically 3 KΩ, use high-impedance loads; if high accuracy or high output currents are required, use external analog
drivers.
For the worst case calculation, if the output resistance is 4 K(maximum limit), the external load (RL) must not be lower
than 2 MΩ (see Figure 68). In this case, the error caused by the load is lower than 1/2 LSB.
To work with loads of 3 K(1 mA at 3V) with an error lower than 1/2 LSB, the output resistance of the external driver should
be lower than:
ROEXT <3 K/(2
*256) = 5.8
Bit 76543210
Name DAC DATAi
Bit Description
7-0 DAC Data. 8-bit unsigned binary value used for the D/A operation.
Embedded Controller Modules (Continued)
Revision 1.07 195 www.national.com
PC87591E/S/L
Output Settling Time
The DAC output settling time depends on the external load characteristics and the required accuracy. Figure 68 shows the
equivalent circuit used for evaluating DAC behavior. Each DAC output has a typical output impedance of 3 KΩ. For example,
if the total load is a 50 pF capacitor only, the output settles to 1/2 LSB within 1 µs. The total load capacitance is comprises
the analog output capacitance (CAO) and the external load capacitance (CL).
Filtering Noise on Output Signals
Output signals may have unwanted noise caused by nearby digital circuits. When using slow changing signals in a noisy
environment, a low-pass filter (LPF) may be added externally. This may also be required in applications where the DAC out-
puts control sensitive circuits like audio amplifiers. This can be implemented as a simple RC circuit. The cutoff frequency of
this LPF should be above the required signal frequency.
Figure 68. DAC Output Equivalent Circuit
CL
RO
CAO RL
ApplicationDAC Output
Equivalent Circuit Load Circuit
VOUT
Embedded Controller Modules (Continued)
www.national.com 196 Revision1.07
PC87591E/S/L
4.13 ACCESS.BUS (ACB) INTERFACE
The PC87591x includes two ACCESS.bus interface modules. The registers of each module are prefixed with ACBn, where
‘n’ is module number 0 or 1. The signal names are suffixed with ‘n’.
Each ACCESS.bus (ACB) interface is a two-wire serial interface that is compatible with the ACCESS.bus physical layer. It
is also compatible with Intel’s SMBus and Philips’ I2C bus. The module can be configured as either a bus master or slave
and can maintain bidirectional communication with multiple master and slave devices. As a slave device, the ACB module
may issue a request to become the bus master.
The ACB interface provides full support for a two-wire ACCESS.bus synchronous serial interface. It permits easy interfacing
to a wide range of low-cost memories and I/O devices, including EEPROMs, SRAMs, timers, A/D converters, D/A convert-
ers, clock chips and peripheral drivers.
4.13.1 Features
ACCESS.bus, SMBus and I2C compliant
ACCESS.bus master
ACCESS.bus slave
One or two user-defined addresses
Global (broadcast) address
ARP address
Supports polling- or interrupt-controlled operation
Generates a wake-up signal on detection of a Start Condition in Power-Down mode
Optional internal pull-up on SDAn and SCLn pins
4.13.2 Functional Description
The ACCESS.bus protocol uses a two-wire interface for bidirectional communication between the ICs connected to the bus.
The two interface lines are the Serial Data Line (SDL) and the Serial Clock Line (SCLn). These lines should be connected
to a positive supply via a pull-up resistor and remain high even when the bus is idle.
The ACCESS.bus protocol supports multiple master and slave transmitters and receivers. Each IC has a unique address
and can operate as a transmitter or a receiver. Some peripherals are receivers only.
During data transactions, the master device initiates the transaction, generates the clock signal and terminates the transac-
tion. For example, when the ACB initiates a data transaction with an attached ACCESS.bus-compliant peripheral, the ACB
becomes the master. When the peripheral responds and transmits data to the ACB, their master/slave (data transaction ini-
tiator and clock generator) relationship is unchanged even though their transmitter/receiver functions are reversed.
Data Transactions
One data bit is transferred during each clock pulse. Data is sampled during the high state of the serial clock (SCLn). Con-
sequently, throughout the clock’s high period, the data should remain stable (see Figure 69). Any change on the SDAn line
while SCLn is in high state during a transaction causes the current transaction to abort. New data should be sent during the
low SCLn state. This protocol permits a single data line to transfer both command/control information and data, using the
synchronous serial clock.
Each data transaction is composed of a Start Condition, a number of byte transfers (set by the software) and a Stop Condi-
tion to terminate the transaction. Each byte is transferred with the most significant bit first. An Acknowledge signal must fol-
low each byte (8 bits). The following sections provide further details of this process.
SDAn
SCLn
Data Line
Stable:
Data Valid
Change
of Data
Allowed
Figure 69. Bit Transfer
Embedded Controller Modules (Continued)
Revision 1.07 197 www.national.com
PC87591E/S/L
At each clock cycle, the slave can stall the master while it handles the previous data or prepares new data. The slave does
this, for each bit transferred or on a byte boundary, by holding SCLn low to extend the clock low period. Typically, slaves
extend the first clock cycle of a transfer if a byte read has not yet been stored or if the next byte to be transmitted is not yet
ready. Some microcontrollers with limited hardware support for the ACCESS.bus extend the access after each bit, thus al-
lowing the software time to handle this bit.
The ACCESS.bus master generates Start and Stop Conditions (control codes). After a Start Condition is generated, the bus
is considered busy. It retains this status for a given amount of time after a Stop Condition is generated. A high-to-low tran-
sition of the data line (SDAn) while the clock (SCLn) is high indicates a Start Condition. A low-to-high transition of the SDAn
line while the SCLn is high indicates a Stop Condition (Figure 70).
Inaddition to the first Start Condition, a Repeated Start Condition can be generated in themiddle of a transaction. This allows
either another device to be accessed or a change in the direction of the data transfer.
Acknowledge Cycle
The Acknowledge cycle consists of two signals:
Acknowledge Clock pulse is sent by the master with each byte transferred
Acknowledge signal is sent by the receiving device (Figure 71)
The master generates the Acknowledge clock pulse on the ninth clock pulse of the byte transfer. The transmitter releases
the SDAn line (permitting it to go high) to allow the receiver to send the Acknowledge signal.The receiver pulls down the
SDAn line during the Acknowledge clock pulse, thus signalling that it has correctly received the last data byte and is ready
to receive the next byte. Figure 72 illustrates the Acknowledge cycle.
SDAn
SCLn SP
Start
Condition Stop
Condition
Figure 70. Start and Stop Conditions
SP
Start
Condition Stop
Condition
SDAn
SCLn
MSB
ACK ACK
12
3 - 6 78912 3 - 8 9
Acknowledge Signal
from Receiver
Byte Complete
Interrupt within
Receiver
Clock Line Held
Low by Receiver
while Interrupt
is Serviced
Figure 71. ACCESS.bus Data Transaction
Embedded Controller Modules (Continued)
www.national.com 198 Revision1.07
PC87591E/S/L
“Acknowledge After Every Byte” Rule
The master generates an Acknowledge clock pulse after each byte transfer. The receiver sends an Acknowledge signal after
every byte is received.
There are two exceptions to the “acknowledge after every byte” rule:
When the master is the receiver, it must indicate to the transmitter an end of data by not acknowledging (negative
acknowledge) the last byte clocked out of the slave. This negative acknowledge still includes the Acknowledge clock
pulse (generated by the master), but the SDAn line is not pulled down.
When the receiver is full or otherwise occupied, or if a problem occurs, it sends a negative acknowledge to indicate
that it cannot accept additional data bytes.
Addressing Transfer Formats
Each device on the bus has a unique address. Before any data is transmitted, the master transmits the address of the slave
being addressed. The slave device should send an Acknowledge signal on the SDAn line once it recognizes its address.
The address consists of the first seven bits after a Start Condition. The eighth bit contains the direction of the data transfer
(R/W). A low-to-high transition during a SCLn high period indicates the Stop Condition and ends the transaction of SDAn
(Figure 73).
When the address is sent, each device in the system compares this address with its own. If there is a match, the device
considers itself addressed and sends an Acknowledge signal. Depending on the state of the R/W bit (1=read, 0=write), the
device acts as a transmitter or a receiver.
The I2C bus protocol allows a general call address to be sent to all slaves connected to the bus. The first byte sent specifies
the general call address (0016); the second byte specifies the general call meaning (for example, “Write slave address by
software only”). Slaves that require data acknowledge the call and become slave receivers; other slaves ignore the call.
S
Start
Condition
SCLn 12
3 - 6 789
Transmitter Stays Off the
Bus During the
Acknowledge Clock
Acknowledge
Signal from Receiver
Figure 72. ACCESS.bus Acknowledge Cycle
Data Output
Transmitter
Data Output
Receiver
SP
Start
Condition Stop
Condition
SDAn
SCLn 1 - 7 891 - 7 891 - 7 89
Address R/WACK Data ACK Data ACK
Figure 73. A Complete ACCESS.bus Data Transaction
Embedded Controller Modules (Continued)
Revision 1.07 199 www.national.com
PC87591E/S/L
Arbitration on the Bus
Multiple master devices on the bus require arbitration between their conflicting bus access demands. Control of the bus is
initially determined according to address bits and clock cycle. If more than one master tries to address the same slave, data
comparisons determine the outcome of this arbitration. In Master mode, the device immediately aborts a transaction if the
value sampled on the SDAn line differs from the value driven by the device. (An exception to this rule is SDAn while receiving
data; in this case, the lines may be driven low by the slave without causing an abort.)
The SCLn signal is monitored for clock synchronization to allow the slave to stall the bus. The actual clock period is the long-
est one set by the master or the slave stall period. The clock high period is determined by the master with the shortest clock
high period.
When an abort occurs during address transmission, a master that identifies the conflict should give up the bus and switch
to Slave mode. It should then continue to sample SDAn to see if it is being addressed by the winning master on the bus.
4.13.3 Master Mode
Requesting Bus Mastership
An ACCESS.bus transaction starts with a master device requesting bus mastership. It asserts a Start Condition, followed by
the address of the device it wants to access. If this transaction is successfully completed, the software may assume that the
device has become the bus master.
For the device to become the bus master, the software should perform the following steps:
1. Configure INTEN in ACBnCTL1 register to the desired operation mode (Polling or Interrupt) and set START in the same
register. This causes the ACB to issue a Start Condition on the ACCESS.bus as soon as the ACCESS.bus is free (some
conditions, such as when BB in ACBnCST register is set to 0, can delay start). It then stalls the bus by holding SCLn low.
2. If a bus conflict is detected (i.e., some other device pulls down the SCLn signal before the PC87591x does), BER in
ACBnST register is set.
3. If there is no bus conflict, MASTER and SDAST in ACBnST register are set.
4. If INTEN in ACBnCTL1 register is set and either BER or SDAST in ACBnST register is set, an interrupt is sent to the core.
Sending the Address Byte
Once the PC87591x is the active master of the ACCESS.bus (MASTER in ACBnST register is set), it can send the address
on the bus. The address sent should not be any of the following:
The PC87591x’s own address, as defined by ADDR in ACBnADDR register, if SAEN in ACBnADDR is set.
The PC87591x’s own address, as defined by ADDR in ACBnADDR2, if SAEN in ACBnADDR2 is set.
The global call address, if GCMTCH in ACBnST register is set.
The ARP address, if ARPMATCH in ACBnST register is set.
To send the address byte, use the following sequence:
1. For a receive transaction where the software requires only one byte of data, the software should set ACK in ACBnCTL1
register. If only an address needs to be sent (e.g., for quick read/write protocols) or if the device requires stall for some
other reason, set STASTRE in ACBnCTL1 register to 1.
2. Write the address byte (7-bit target device address) and the direction bit to ACBnSDA register. This causes the module
to generate a transaction. At the end of this transaction, the acknowledge bit received is copied to NEGACK in ACBnST
register. During the transaction, the SDAn and SCLn lines are continuously checked for conflict with other devices. If a
conflict is detected, the transaction is aborted, BER in ACBnST register is set and MASTER in ACBnST register is
cleared.
3. If STASTRE in ACBnCTL1 register is set and the transaction was successfully completed (i.e., both BER and NEGACK
in ACBnST register are cleared), STASTR in ACBnST register is set. In this case, the ACB stalls any further AC-
CESS.bus operations (i.e., holds SCLn low). If INTEN in ACBnCTL1 register is set, it also sends an interrupt to the core.
4. Iftherequesteddirectionistransmitandthestarttransactionwascompletedsuccessfully(i.e.,neitherNEGACKnorBER
in ACBnST register is set and no other master has accessed the device), SDAST in ACBnST register is set to indicate
that the module awaits attention.
5. If the requested direction is receive, the start transaction was completed successfully and STASTRE in ACBnCTL1 reg-
ister is cleared, the module starts receiving the first byte automatically.
6. Check that both BER and NEGACK in ACBnST register are cleared. If INTEN in ACBnCTL1 register is set, an interrupt
is generated when either BER or NEGACK is set.
Embedded Controller Modules (Continued)
www.national.com 200 Revision1.07
PC87591E/S/L
Master Transmit
After becoming the bus master, the device can start transmitting data on the ACCESS.bus.
To transmit a byte, the software should:
1. Check that BER and NEGACK bits in ACBnST register are cleared and SDAST bit is set. In addition, if STASTRE bit in
ACBnCTL1 register is set, make sure that STASTR bit in ACBnST register is cleared.
2. Write the data byte to be transmitted to ACBnSDA register.
When the slave responds with a negative acknowledge, NEGACK in ACBnST register is set and SDAST in ACBnST register
remains cleared. In this case, if INTEN bit in ACBnCTL1 register is set, an interrupt is sent to the core.
Master Receive
After becoming the bus master, the device can start receiving data on the ACCESS.bus.
To receive a byte, the software should:
1. Check that SDAST bit in ACBnST register is set and BER bit is cleared. In addition, if STASTRE bit in ACBnCTL1 register
is set, make sure that STASTR in ACBnST register is cleared.
2. If the next byte is the last byte that should be read, set ACK bit in ACBnCTL1 register to 1. This causes a negative ac-
knowledge to be sent.
3. Read the data byte from ACBnSDA register.
Master Stop
To end a transaction, set STOP in ACBnCTL1 register before clearing the current stall flag (i.e., SDAST, NEGACK or STAS-
TR in ACBnST register). This causes the module to send a Stop Condition immediately and to clear STOP in ACBnCTL1
register. A Stop Condition may be issued only when the PC87591x is the active bus master (MASTER in ACBnST register
is set to 1).
Master Bus Stall
The ACB module can stall the ACCESS.bus between transfers while waiting for the core’s response. The ACCESS.bus is
stalled by holding the SCLn signal low after the acknowledge cycle. Note that this is interpreted as the start of the following
bus operation. The user must make sure that the next operation is prepared before the flag that causes the bus stall is
cleared.
The flags that can cause a bus stall in Master mode are:
Negative acknowledge after sending a byte (NEGACK in ACBnST register is set to 1).
SDAST in ACBnST register is set to 1.
STASTRE in ACBnCTL1 register is set to 1 after a successful start (STASTR in ACBnST is set to 1).
Repeated Start
A repeated start is performed when the PC87591x is already the bus master (MASTER in ACBnST register is set). In this
case, the ACCESS.bus is stalled and the ACB module awaits core handling due to a negative acknowledge (NEGACK in
ACBnST register is set to 1), an empty buffer (SDAST in ACBnST is set to 1) and/or a stall after start (STASTR in ACBnST
is set to 1).
For a repeated start:
1. Set START in ACBnCTL1 register to 1.
2. In Master Receive mode, read the last data item from ACBnSDA.
3. Follow the address send sequence, as described in “Sending the Address Byte” on page 199.
4. If the ACB is awaiting handling because STASTR in ACBnST is set to 1, clear it only after writing the requested address
and direction to ACBnSDA.
Master Error Detection
The ACB detects an illegal Start or Stop Condition (i.e., a Start or Stop Condition within the data transfer or the acknowledge
cycle) and a conflict on the data lines of the ACCESS.bus. If an illegal condition is detected, BER is set and Master mode is
exited (MASTER in ACBnST register is cleared).
Bus Idle Error Recovery
When a request to become the active bus master or a restart operation fails, BER in ACBnST register is set to indicate the
error. In some cases, both the PC87591x and the other device may identify the failure and leave the bus idle. In this case,
the start sequence may not finish and the ACCESS.bus may remain deadlocked.
To recover from deadlock, use the following sequence:
Embedded Controller Modules (Continued)
Revision 1.07 201 www.national.com
PC87591E/S/L
1. Clear BER in ACBnST register and BB in ACBnCST register.
2. Wait for a time-out period to check that there is no other active master on the bus (i.e., BB in ACBnCST remains cleared).
3. Disable and then re-enable the ACB to put it in non-addressed Slave mode. (This completely resets the module.)
At this point, some of the slaves may not identify the bus error. To recover, the ACB module becomes the bus master. It
asserts a Start Condition, sends an address byte and then asserts a Stop Condition that synchronizes all the slaves.
4.13.4 Slave Mode
A slave device waits in Idle mode for a master to initiate a bus transaction. Whenever the ACB module is enabled is not
acting as a master (i.e., MASTER in ACBnST register is cleared), it acts as a slave device.
Once a Start Condition on the bus is detected, the PC87591x checks whether the address sent by the current master match-
es any of the following possibilities:
The ADDR value in ACBnADDR register, if SAEN in this register is set to 1
The ADDR value in ACBnADDR2 register, if SAEN in this register is set to 1
The global call address (0016), if GCMEM in ACBnCTL1 register is set to 1
The global ARP address (110 00012), if ARPMEN in ACBnCTL3 register is set to 1.
The address match is checked even when MASTER in ACBnST register is set. If a bus conflict (on SDAn or SCLn) is de-
tected, BER is set, MASTER is cleared and the PC87591x continues to search the received message for a match.
If an address ARP or global match is detected:
1. The PC87591x asserts its SDAn pin during the acknowledge cycle.
2. MATCH in ACBnCST register, MATCHAF in ACBnST register (or GCMATCH if it is a global call address match, or ARP-
MATCH if it is an ARP address) and NMATCH in ACBnST register are set. If XMIT in ACBnST register is set (i.e., Slave
Transmit mode), SDAST in the same register is also set to indicate that the buffer is empty.
3. If INTEN in ACBnCTL1 register is set, an interrupt is generated if both INTEN and NMINTE in ACBnCTL1 register are set.
4. The software then reads XMIT in ACBnST register to identify the direction requested by the master device; it then clears
NMATCH in the same register so that future byte transfers are identified as data bytes.
Slave Receive and Transmit
Slave Receive and Transmit are performed after a match is detected and the data transfer direction is identified. After a byte
transfer, the ACB module extends the acknowledge clock until the software reads or writes ACBnSDA register. The receive
and transmit sequences are identical to those used in the master routine.
Slave Bus Stall
When operating as a slave, the PC87591x stalls the ACCESS.bus by extending the first clock cycle of a transaction in the
following cases:
SDAST in ACBnST register is set.
NMATCH in ACBnST register and NMINTE in ACBnCTL1 register are set.
Slave Error Detection
The ACB detects illegal Start and Stop Conditions (occurring within the data transfer or the acknowledge cycle) on the AC-
CESS.bus. When an illegal Start or Stop Condition is detected, BER is set and MATCH and GMATCH are cleared, setting
the module as an unaddressed slave.
4.13.5 Power-Down
When the PC87591x is in Idle mode, the ACB module is not active but retains its status. If the ACB is enabled (ENABLE in
ACBnCTL2 register is set) on detection of a Start Condition, a wake-up signal is issued to the MIWU. This signal may be
used to switch the PC87591x to Active mode.
Following the Start Condition that woke up the PC87591x, the ACB module can not check the address byte for a match. The
ACB responds with a negative acknowledge. The device should resend both the Start Condition and the address after the
PC87591x has had time to wake up.
Before entering Idle mode, make sure that BUSY in ACBnCST register is inactive. This guarantees that the PC87591x will
not stop responding after it acknowledges an address that was sent.
4.13.6 SDA and SCL Pin Configuration
The SDAn and SCLn are open collector signals that the user can choose to enable or disable. SDAn and SCLn also have
internal pull-up resistors that the user may enable. For more information about configuring these pins, see Table 8 on
page 54 and Section 4.5.2 on page 114.
Embedded Controller Modules (Continued)
www.national.com 202 Revision1.07
PC87591E/S/L
4.13.7 ACB Clock Frequency Configuration
The ACB module enables the user to set the ACCESS.bus clock frequency. The SCLn clock period is set by SCLFRQ in
ACBnCTL2 and ACBnCTL3 registers. This clock low period may be extended by stall periods initiated by the ACB module
or by another ACCESS.bus device. In case of a conflict with another bus master, a shorter clock high period may be forced
by the other bus master until the conflict is resolved.
4.13.8 ACB Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
ACB Register Map
ACB Serial Data Register (ACBnSDA)
The ACBnSDA register is a shift register used to transmit and receive data. The most significant bit is transmitted (received)
first and the least significant bit is transmitted (received) last. Reading or writing to the ACBnSDA register is allowed only
when SDAST in ACBnST register is set or for repeated starts after setting the START bit. An attempt to access the register
in other cases may produce unpredictable results.
Locations: Channel - 1 00 FF6016
Channel - 2 00 FFE016
Type: R/W
Mnemonic Register Name Type
ACBnSDA ACB Serial Data R/W
ACBnST ACB Status Varies per bit
ACBnCST ACB Control Status Varies per bit
ACBnCTL1 ACB Control 1 R/W
ACBnADDR ACB Own Address R/W
ACBnADDR2 ACB Own Address 2 R/W
ACBnCTL2 ACB Control 2 R/W
ACBnCTL3 ACB Control 3 R/W
Bit 76543210
Name Data
Bit Description
7-0 Data.
Embedded Controller Modules (Continued)
Revision 1.07 203 www.national.com
PC87591E/S/L
ACB Status Register (ACBnST)
The ACBnST register maintains current ACB status. Some of its bits may be cleared by software, as described below. On
reset, and when the module is disabled, ACBnST is cleared (0016).
Location: Channel - 1 00 FF6216
Channel - 2 00 FFE216
Type: varies per bit
Bit 76543210
Name SLVSTP SDAST BER NEGACK STASTR NMATCH MASTER XMIT
Reset 00000000
Bit Type Description
0ROXMIT (Transmit Mode).
0: ACB not in master/slave Transmit mode
1: ACB in master/slave Transmit mode
1ROMASTER (Master Mode).
0: Arbitration loss (BER is set) or Stop Condition occurred
1: ACB in Master mode (successful request for bus mastership)
2 R/W1C NMATCH (New Match). The bit is set when the address byte following a Start Condition or a
repeated start causes an address match, ARP address match or a global call match. NMATCH is
cleared by writing 1 to it. Writing 0 to NMATCH is ignored. If INTEN in ACBnCTL1 register is set, an
interrupt is sent when this bit is set.
3 R/W1C STASTR (Stall After Start). The bit is set by the successful completion of sending an address (i.e.,
a Start Condition sent without a bus error or negative acknowledge), if STASTRE in ACBnCTL1
register is set. This bit is ignored in Slave mode. When STASTR is set, it stalls the ACCESS.bus (by
pulling down the SCL line) and suspends any further action on the bus (e.g., receiving the first byte
in Master Receive mode). In addition, if INTEN in ACBnCTL1 register is set, it also causes the ACB
module to send an interrupt to the core. Writing 1 to STASTR clears it. It is also cleared when the
module is disabled and is always cleared when STASTRE is cleared. Writing 0 to STASTR has no
effect.
4 R/W1C NEGACK (Negative Acknowledge). The bit is set by hardware when a transmission is not
acknowledged on the ninth clock (in this case, SDAST is not set). Writing 1 to NEGACK clears it. It is
also cleared when the module is disabled. Writing 0 to NEGACK is ignored.
5 R/W1C BER (Bus Error). The bit is set by the hardware when a Start or Stop Condition is detected during
data transfer (i.e., Start or Stop Condition during the transfer of bits 2 through 8 and acknowledge
cycle) or when an arbitration problem is detected. Writing 1 to BER clears it. It is also cleared when
the module is disabled. Writing 0 to BER is ignored.
6ROSDAST (SDA Status). When set, this bit indicates that the SDA data register is waiting for data
(Transmit mode - master or slave) or holds data that should be read (Receive mode - master or
slave). This bit is cleared when reading from ACBnSDA register during a receive or when written to
during a transmit. When START in the ACBnCTL1 is set, reading ACBnSDA register does not clear
SDAST. This enables the ACB to send a repeated start in Master Receive mode.
7 R/W1C SLVSTP (Slave Stop). When set, SLVSTP indicates that a Stop Condition was detected after a slave
transfer (i.e., after a slave transfer in which MATCH or GCMATCH was set). Writing 1 to SLVSTP
clears it. It is also cleared when the module is disabled. Writing 0 to SLVSTP is ignored.
Embedded Controller Modules (Continued)
www.national.com 204 Revision1.07
PC87591E/S/L
ACB Control Status Register (ACBnCST)
The ACBnCST register maintains current ACB status and controls several ACB module functions, as described below. On
reset and when the module is disabled, the non-reserved bits of ACBnCST are cleared (0016).
Location: Channel 1 - 00 FF6416
Channel 2 - 00 FFE416
Type: Varies per bit
Bit 76543210
Name ARPMATCH MATCHAF TGSCL TSDA GCMATCH MATCH BB BUSY
Reset 00000000
Bit Type Description
0ROBUSY. When set (1), indicates that the ACB module is in one of the following states:
Generating a Start Condition
In Master mode (MASTER in ACBnST register is set)
In Slave mode (MATCH or GMATCH in ACBnCST register is set)
In the period between detecting a Start Condition and completing the reception of the address byte;
after this, the ACB either becomes not busy or enters Slave mode.
The BUSY bit is cleared by the completion of any of the above states or by disabling the module. It
should always be written 0.
1 R/W1C BB (Bus Busy). When set (1), indicates the bus is busy. It is set either when the bus is active (i.e., a
low level on either SDA or SCL) or by a Start Condition. It is cleared when the module is disabled, on
detection of a Stop Condition or by writing 1 to this bit. See Section 4.13.9 on page 207 for a
description of the use of this bit.
2ROMATCH (Address Match). In Slave mode, MATCH is set (1) when SAEN in ACBnADDR register is
set and the first seven bits of the address byte (the first byte transferred after a Start Condition) match
the 7-bit address in ACBnADDR register. It is cleared by Start Condition, a Repeated Start or a Stop
Condition (including illegal Start or Stop Condition).
3ROGCMATCH (Global Call Match). In Slave mode, GCMTCH is set (1) when GCMEN in ACBnCTL1
register is set and the address byte (the first byte transferred after a Start Condition) is 0016.Itis
cleared by a Start Condition, a Repeated Start or a Stop Condition (including illegal Start or Stop
Condition).
4ROTSDA (Test SDA Line). Reads the current value of the SDA line. This bit can be used while
recovering from an error condition in which the SDA line is constantly pulled low by a slave that went
out of synch. Data written to this bit is ignored.
5 R/W TGSCL (Toggle SCL Line). Enables toggling the SCL line during the process of error recovery. When
the SDA line is low, writing 1 to this bit toggles the SCL line for one cycle. Writing 1 to TGSCL while
SDA is high is ignored. The bit is cleared when the clock toggle is completed.
6ROMATCHAF (Match Address Field). When the MATCH bit is set, MATCHAF indicates with which of
the two possible slave addresses (ADDR cleared in ACBnADDR register or set in ACBnADDR2
register) the match has occurred. If both addresses match, the bit is cleared.
7ROARPMATCH (ARP address Match). In Slave mode, ARPMTCH is set (1) when ARPMEN in
ACBnCTL3 register is set and the address byte (the first byte transferred after a Start Condition) is
110 00012. It is cleared by Start Condition, a Repeated Start or a Stop Condition (including illegal Start
or Stop Condition).
Embedded Controller Modules (Continued)
Revision 1.07 205 www.national.com
PC87591E/S/L
ACB Control Register 1 (ACBnCTL1)
The ACBnCTL1 register is a byte-wide, read/write register that configures and controls the ACB module. On reset, the
ACBnCTL1 is cleared (0016).
Location: Channel 1 - 00 FF6616
Channel 2 - 00 FFE616
Type: R/W
Bit 76543210
Name STASTRE NMINTE GCMEN ACK Reserved INTEN STOP START
Reset 00000000
Bit Description
0START. Should be set when a Start Condition must be generated on the ACCESS.bus.
If the PC87591x is not the active bus master (MASTER in ACBnST register is set to 0), setting START gener-
ates a Start Condition as soon as the ACCESS.bus is free (BB in ACBnCST register is set to 0). An address
transmission sequence should then be performed.
If the PC87591x is the active master of the bus (MASTER in ACBnST register is set to 1), when START is set,
a write to ACBnSDA register generates a Start Condition. ACBnSDA data is then transmitted as the slave’s ad-
dress and the requested transfer direction.
In case of a Repeated Start Condition, the set bit may be used to switch the direction of the data flow between
the master and the slave or to choose another slave device without using a Stop Condition in between.
The START bit is cleared either when the Start Condition is sent or on detection of a Bus Error (BER in ACBnST
register is set to 1).
This bit should be set only when in Master mode or when requesting Master mode.
1STOP. In Master mode, setting this bit generates a Stop Condition, which completes or aborts the current
message transfer. This bit clears itself after STOP is issued.
2INTEN (Interrupt Enable). When INTEN is cleared (0), the ACB interrupt is disabled. When INTEN is set,
interrupts are enabled. An interrupt is generated (the interrupt signals to the ICU are high) on one of the
following events:
An address match is detected (NMATCH in ACBnST register is set to1 and NMINTE in ACBnCTL1 register is
set to 1).
A Bus Error occurs (BER in ACBnST register is set to 1).
A negative acknowledge is received after sending a byte (NEGACK in ACBnST register is set to 1).
Acknowledgment of each transaction (same as the hardware set of SDAST in ACBnST).
In Master mode, if STASTRE in ACBnCTL1 register is set to 1 after a successful start (STASTR in ACBnST
register is set to 1).
Detection of a Stop Condition while in Slave mode (SLVSTP in ACBnST register is set to 1).
3Reserved.
4ACK (Acknowledge). When acting as a receiver, this bit holds the value of the next acknowledge cycle. It
should be set when a negative acknowledge must be issued on the next byte. This bit is cleared (0) after the
first acknowledge cycle.
This bit is ignored when in Transmit mode. It cannot be reset by software.
5GCMEN (Global Call Match Enable). When set, enables the matching of an incoming address byte to the
general call address (Start Condition followed by address byte of 0016) while the ACB is in Slave mode. When
cleared, the ACB does not respond to a global call.
6NMINTE (New Match Interrupt Enable). When set, enables the interrupt on a new match (i.e., when NMATCH
in ACBnST register is set). The interrupt is issued only if INTEN in ACBnCTL1 register is set.
7STASTRE (Stall After Start Enable). When set (1), enables the Stall After Start mechanism. In such a case,
the ACB stalls the bus after the address byte. When STASTRE is cleared, STASTR in ACBnST is always
cleared.
Embedded Controller Modules (Continued)
www.national.com 206 Revision1.07
PC87591E/S/L
ACB Own Address Register (ACBnADDR and ACBnADDR2)
The ACBnADDR and ACBnADDR2 registers hold the module’s ACCESS.bus addresses. The reset value of these registers
are undefined.
ACBnADDR:
Location: Channel 1 - 00 FF6816
Channel 2 - 00 FFE816
ACBnADDR2:
Location: Channel 1- 00 FE6C16
Channel 2- 00 FFEC16
Type: R/W
ACB Control Register 2 (ACBnCTL2)
The ACBnCTL2 register enables/disables the module and determines the ACB clock rate. On reset and while the module is
disabled (ENABLE in ACBnCTL2 register is set to 0), ACBnCTL2 is cleared (0016).
Location: Channel 1 - 00 FF6A16
Channel 2 - 00 FFEA16
Type: R/W
Bit 76543210
Name SAEN ADDR
Bit Description
6-0 ADDR (Address). Holds the 7-bit ACCESS.bus address of the PC87591x. When in Slave mode, the first seven
bits received after a Start Condition are compared to this field (the first bit received is compared to bit 6, the next
bit to bit 5 and so on until the last bit, which is compared to bit 0). If the address field matches the received data
and SAEN in ACBnADDR register is set to 1, a match is declared.
7SAEN (Slave Address Enable). When set (1), indicates that the ADDR field holds a valid address and enables
the match of ADDR to an incoming address byte. When cleared, the ACB does not check for an address match.
Bit 76543210
Name SCLFRQ6-0 ENABLE
Reset 00000000
Bit Description
0ENABLE. When set, the ACB module is enabled. When the Enable bit is cleared, the ACB module is disabled,
ACBnCTL1, ACBnST and ACBnCST are cleared and the clocks are halted.
7-1 SCLFRQ6-0 (SCL Frequency bits 6 through 0). This field, together with SCLFRQ8-7 in ACBCTL3 register,
defines the SCL’s period (low time and high time) when the PC87591x serves as a bus master. The clock low
time and high time are defined as follows:
tSCL =4*SCLFRQ*tCLK
tSCLl =t
SCLh
where tCLK is the PC87591x clock cycle when in Active mode (see Section 7.6.3 on page 385).
SCLFRQ may be programed to values in the range of 00 00010002(810) through 11 11111112(51110). Values
outside this range gives unpredictable results.
Embedded Controller Modules (Continued)
Revision 1.07 207 www.national.com
PC87591E/S/L
ACB Control Register 3 (ACBnCTL3)
The ACBnCTL3 register expands the clock pre-scaler field and enables the match to ARP addresses. ACBnCTL2 is cleared
on reset (0016).
Location: Channel 1 -00 FF6E16
Channel 2- 00 FFEE16 (Update for Multiple Instances)
Type: R/W
4.13.9 Usage Hints
1. When the ACB is disabled, BB in ACBnCST register is cleared. After the ACB is enabled (by setting ENABLE in
ACBnCTL2 register), the bus may be in the middle of a transaction with another device in systems with more than one
master. This status is not reflected by BB.
To prevent bus errors, the ACB must synchronize with the bus activity status before issuing a request to become the bus
master for the first time. The software should check that there is no activity on the bus by checking the BB bit after the
time-out period allowed by the bus.
2. When waking up from power-down before checking MATCH in ACBnCST register, check BUSY in the same register to
make sure that the address transaction is completed.
3. The BB bit can help solve a deadlock in which two or more devices detect a usage conflict on the bus and both cease
being bus masters at the same time. In this situation, the BB bits of both devices are active (because each “detects”
another master currently performing a transaction, while in fact there is no transaction). This potentially causes the bus
to stay locked until a device on the bus sends a Stop Condition (through STOP in ACBnCTL1 register).
The BB bit allows the software to monitor bus usage so that it can detect whether the bus remains unused over a certain
period of time while BB is set. It also avoids sending a STOP signal in the middle of the transaction of another device on
the bus.
4. In some cases, the bus may get stuck with the SCL and/or SDA lines active, such as when an erroneous Start or Stop
Condition occurs in the middle of a slave receive session.
If the SCL line is stuck active, the module that holds the bus must release it.
If the SDA line is stuck active, the sequence below releases the bus (Note:In normal cases, SCL may be toggled only
by the bus master; this sequence is a recovery scheme which is an exception and should be only used if there is no other
master on the bus):
a. Disable and re-enable the module to set it for the Slave mode not addressed.
b. Set START in ACBnCTL1 register to attempt to issue a Start Condition.
c. Check if the SDA line is active (low) by reading TSDA in ACBnCST register. If it is active, issue a single SCL cycle
by writing 1 to TGSCL in the same register. If it is not active, skip to step e.
d. Check if MASTER in ACBnST register is set, which indicates that the Start Condition was sent. If it is not set, repeat
step c and this step until the SDA is released.
e. Clear BB. This enables START to be executed. Continue according to “Bus Idle Error Recovery” on page 200.
Bit 76543210
Name Reserved ARPMEN SCLFRQ8-7
Reset 00000000
Bit Description
1-0 SCLFRQ8-7 (SCL Frequency bits 8 and 7). Extends SCLFRQ field and is concatenated with bits 0-6, which
are part of ACBnCTL2 register. Detailed use of SCLFRQ is provided in the SCLFRQ6-0 description in
ACBnCTL2.
2ARPMEN (ARP Match Enable). When set, enables the matching of an incoming address byte to the SMBus
ARP address (110 00012) while the ACB is in Slave mode. When cleared, the ACB does not respond to an ARP
address.
7-3 Reserved.
Embedded Controller Modules (Continued)
www.national.com 208 Revision1.07
PC87591E/S/L
4.14 ANALOG COMPARATORS MONITOR (ACM)
The Analog Comparators Monitor (ACM) checks the voltage level of eight analog inputs and reports their values to the core.
The ACM can either measure the voltage of each input with 6-bit resolution or compare the level of all eight inputs with a
programmable threshold.
An operation burst includes either the voltage measurement of all inputs or one comparison check of all inputs to a fixed
threshold. The bursts may be triggered by a low-frequency clock for periodic operation.
4.14.1 Features
Voltage measurement
Eight analog inputs
6-bit resolution
0V to VCC Full Scale (FS) input voltage range
High-impedance inputs
Comparison check
6-bit threshold resolution
Simultaneous on all inputs
Ratiometric measurement using VCC
Digital reading output
Eight buffers for voltage value
One buffer for comparison check
170 µs voltage measurement of all the inputs
Polling- or interrupt-driven interface
Power consumption
Zero current when disabled
Low average current in Idle mode
4.14.2 Functional Description
Inputs. The ACM has eight analog inputs with a voltage ranging from 0V to VCC (FS), as shown in Figure 74.
The voltage level at each input is compared with a reference level, generated by a 6-bit D/A converter.
Operation. The ACM can be operated in one of three modes:
Voltage Level Burst mode - The reference level generated by the D/A converter is ramped from 0V to FS by incre-
menting the value loaded into the converter. Whenever the ramp crosses the level of an input, its comparator toggles
state, and the D/A loaded value is latched into the corresponding Voltage Level Buffer. At the end of the ramp, exe-
cution stops and a set of eight voltage level values (one per input) is available.
Threshold Comparison Burst mode - A programmable value is loaded into the D/A converter, generating a constant
threshold level. A bit is set for each input if the input’s voltage level is higher than the threshold. At the end of the
single comparison, the Comparison Result register holds the status of the eight inputs.
Low Power Threshold Comparison mode - The inputs are periodically compared with a fixed threshold. The compar-
ison is triggered by a low rate signal from the TWD module (T0IN). In addition, an interrupt is generated if at least
one input is below (or above) the threshold.
Timing. When the PC87591x is in Active or Active Executing Wait mode, ACM module timing is based on the core domain
clock (CLK). When the PC87591x is in Idle mode, timing is based on the low frequency clock (LFCLK) to minimize power
consumption.
Embedded Controller Modules (Continued)
Revision 1.07 209 www.national.com
PC87591E/S/L
4.14.3 Voltage Level
VCC supply is the reference and full scale (FS) voltage for the D/A converter. This enables ratiometric voltage measurement
(parts of FS), were VCC is used to power an external voltage divider connected to the KBSINn inputs.
The 6-bit Voltage Level Data field (VOLTLVL) in VOLDATn (n = 0 to 7) registers and the Comparison Threshold Data field
(THRSHD5-THRSHD0) in THRDAT register are converted to input voltage, according to input voltage ratio (to FS), as
shown in Figure 75.
D/A Converter
(6-bit)
Control
Logic
Voltage In0
Interrupt
System
Peripheral Bus
ACM
Clock
+
+
+
Voltage In1
Voltage In7
Comparison
Control/Status
LFCLK
Figure 74. ACM Functional Diagram
T0IN
Result
PC87591x
KBSIN1
KBSIN7
KBSIN0
Embedded Controller Modules (Continued)
www.national.com 210 Revision1.07
PC87591E/S/L
4.14.4 ACM Operation
Reset
The ACM is initialized by core domain reset (Section 3.2 on page 65 describes the PC87591x reset events).
Upon reset, the ACM is disabled, with all interrupt sources masked and the over/under threshold select set to “below”. All
Event status bits are reset. The trigger division factor, as well as the data sampling delay, are set to their maximum value
(for the slowest ACM operation speed). The comparison threshold is set to zero.
All control, configuration and status registers are reset to their default values, as indicated in Section 4.14.5 on page 212.
Voltage Level Data Buffer registers and the Comparison Result register’s values are invalid until the first measurement oc-
curs (on each of them).
Sampling Delay
This delay separates between the new value being loaded into the D/A converter and the data being sampled into the Volt-
age Level Data Buffer registers and the Comparison Result register. Its value should be longer than the total time required
by the D/A output to settle (within 1/2 LSB of 6 bits) and the comparators to toggle their state.
The value set by SMPDLY field in ACMTIM register is expressed in terms of core CLK clock cycles. The maximum frequency
at which each delay may be used is specified in the register’s description.
Initializing the ACM
The ACM must be initialized before it is enabled and used. The following operations should be done:
Select the ACM Mode Control by setting ACMMOD field in ACMCNF register.
Enable interrupts are required using the following bits of ACMCNF register:
Interrupt from End-of-Measurement Event Enable by setting INTEMEN bit.
Interrupt from Over/Under Threshold Event Enable by setting INTOUEN bit.
Select Over or Under Threshold mode, using OVUNSEL bit in ACMCNF register.
Set the data sampling delay using SMPDLY field in ACMTIM register.
Select the low power trigger rate by setting T0DIV field in ACMTIM register.
Select the Comparison Threshold Data for wake-up by setting THRSHD field in THRDAT register.
After initializations are done, the ACM may be enabled by writing 1 to START bit in ACMCTS register.
Note: Setting any of the above bits/fields during ACM operation may cause unpredictable results.
0123(64)
6362
. . . . .
0
1/64
2/64
3/64
62/64
63/64
FS
. . . . .
Level Data
Voltage Ratio to VCC (FS)
Figure 75. Level Data to Input Voltage Ratio Conversion
Embedded Controller Modules (Continued)
Revision 1.07 211 www.national.com
PC87591E/S/L
Interrupt Structure
The ACM Interrupt is generated to the core if an event from Table 26 becomes active. Since the events are enabled in dif-
ferent ACM operation modes, only one event may occur at a time.
Table 26. ACM Interrupt Structure
When an event flag and its related mask bit are set (enabled), the ACM Interrupt request is asserted. This is indicated by
a high level of the ACM Interrupt signal.
The software must reset the event flag (or its mask bit) to de-assert the ACM Interrupt request.
All the event flags (EOMEV, EOCEV and OVUNTHEV) are cleared by writing 1 to START in ACMCTS register.
TheACMInterruptisroutedbothtotheICUandtotheMIWUasanACMIsignal(seeSection 4.3onpage 98and Section 4.4
on page 105).
ACM Operating Sequences
The ACM has three operating modes:
Voltage Level Burst mode
Threshold Comparison Burst mode
Low-Power Threshold Comparison mode
After the ACM is properly initialized, one of these modes should be used. The operation sequences are as follows:
Voltage Level Burst Mode (ACMMOD = 012)
1. Start a new burst of eight voltage measurements by setting START bit in ACMCTS register to 1.
2. When End-of-Voltage level measurement burst is reached, software can detect the event by waiting for EOMEV in
ACMCTS register to be set to 1.
3. Read measured voltage level - Input 0, for channel 0, by reading VOLTLVL in VOLDAT0 register.
4. Read measured voltage level - Input 1, for channel 1, by reading VOLTLVL in VOLDAT1 register.
5. Read measured voltage level - Input 2, for channel 2, by reading VOLTLVL in VOLDAT2 register.
6. Read measured voltage level - Input 3, for channel 3, by reading VOLTLVL in VOLDAT3 register.
7. Read measured voltage level - Input 4, for channel 4, by reading VOLTLVL in VOLDAT4 register.
8. Read measured voltage level - Input 5, for channel 5, by reading VOLTLVL in VOLDAT5 register.
9. Read measured voltage level - Input 6, for channel 6, by reading VOLTLVL in VOLDAT6 register.
10.Read measured voltage level - Input 7, for channel 7, by reading VOLTLVL in VOLDAT7 register.
11.Clear the event flag (release the ACM interrupt if enabled) by writing 1 to EOMEV in ACMCTS register.
Threshold Comparison Burst Mode -(ACMMOD = 102)
1. Set the desired threshold value in bits THRSHD(5-0) in THRDAT register.
2. Start a new burst of threshold comparison by setting START in ACMCTS register to 1.
3. When End-of-Threshold comparison burst is reached, software can detect the event by waiting for EOCEV in ACMCTS
register to be set to 1.
4. Read comparison result for inputs 0 to 7 by reading bits CMPIN(0-7) in CMPRES register.
5. Clear the event flag by writing 1 to EOCEV in ACMCTS register.
Event Flag Register
Mnemonic Mask Bit Register
Mnemonic Description
EOMEV ACMCTS INTEMEN ACMCNF End-of-Measurement event and associated interrupt enable
OVUNTHEV ACMCTS INTOUEN ACMCNF Over/Under Threshold event and associated interrupt enable
Embedded Controller Modules (Continued)
www.national.com 212 Revision1.07
PC87591E/S/L
Low-Power Threshold Comparison Mode (ACMMOD = 112)
1. Set the desired threshold value in bits THRSHD(5-0) in THRDAT register.
2. Start a new periodic, low-power threshold comparison by setting START in ACMCTS register to 1.
3. When there is an input under (or over) threshold event, software can detect the event by waiting for OVUNTHEV in
ACMCTS register to be set to 1.
4. Read comparison result for inputs 0 to 7 by reading bits CMPIN(0-7) in CMPRES register.
5. Clear the event flag (release the ACM interrupt if enabled) by writing 1 to OVUNTHEV in ACMCTS register.
Polling Driven Operation. Valid measurement results may be retrieved by polling the event flags in ACMCTS register,
EOMEV, EOCEV or OVUNTHEV, according to the selected operation mode. After reading the relevant data, clear the polled
event flag by writing 1.
Interrupt Driven Operation. When receiving an active ACM interrupt request, the software should check the two event
flags, EOMEV or OVUNTHEV, to identify the source of the interrupt. After reading the relevant data, clear (by setting to 1)
the event flag that caused the interrupt. Clearing the flag releases the ACM interrupt request.
4.14.5 ACM Registers
The ACM control/status and data out register set interfaces with the core through the Peripheral bus.
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
ACM Register Map
The ACM register set contains four control and status registers and nine data out registers.
Table 27. ACM Register Map
Mnemonic Register Name Type
ACMCTS ACM Control and Status Varies per bit
ACMCNF ACM Configuration R/W
ACMTIM ACM Timing Control R/W
THRDAT Comparison Threshold Data R/W
CMPRES Comparison Result RO
Reserved
VOLDAT0 Voltage Level Data - Input 0 RO
VOLDAT1 Voltage Level Data - Input 1 RO
VOLDAT2 Voltage Level Data - Input 2 RO
VOLDAT3 Voltage Level Data - Input 3 RO
VOLDAT4 Voltage Level Data - Input 4 RO
VOLDAT5 Voltage Level Data - Input 5 RO
VOLDAT6 Voltage Level Data - Input 6 RO
VOLDAT7 Voltage Level Data - Input 7 RO
Embedded Controller Modules (Continued)
Revision 1.07 213 www.national.com
PC87591E/S/L
ACM Control and Status Register (ACMCTS)
This register controls the operation and indicates the status of the ACM module. ACMCTS is cleared (0016) on reset.
Location: 00 FD4016
Type: Varies per bit
Bit 76543210
Name Reserved OVUNTHEV EOCEV EOMEV START
Reset 00000000
Bit Type Description
0WSTART (ACM Operation Start). Start trigger for the ACM operation in the mode selected by ACMMOD
field in ACMCNF register. If the new ACMMOD value differs from the value currently in use, all event
flags (EOMEV, EOCEV, OVUNTHEV) are cleared and operation in the new mode begins. Writing a 1 to
the START bit without modifying the ACMMODE value is ignored by the module.
0: No effect - (default)
1: Operation start trigger - automatically returns to 0 after start
1 R/W1C EOMEV (End-of-Measurement Event). End of voltage level measurement burst (for all eight inputs).
The bit is set only when the ACM is in Voltage Level Burst mode (ACMMOD = 012in ACMCNF
register).
0: Measurement in progress, or not in Voltage Level Burst mode (default)
1: End of voltage level measurement burst
2 R/W1C EOCEV (End-of-Comparison Event). End of threshold comparison in Threshold Comparison Burst
mode (ACMMOD = 102in ACMCNF register).
0: Comparison in progress, or not in Threshold Comparison Burst mode (default)
1: End of threshold comparison
3 R/W1C OVUNTHEV (Over/Under Threshold Event). At least one input is above (or below) the voltage
threshold value. The bit is set only when the ACM is in Low Power Threshold Comparison mode
(ACMMOD = 112in ACMCNF register).
0: No input above (or below) the threshold, or not in Low Power Threshold Comparison mode (default)
1: One or more inputs above (or below) the threshold
7-4 Reserved.
Embedded Controller Modules (Continued)
www.national.com 214 Revision1.07
PC87591E/S/L
ACM Configuration Register (ACMCNF)
This register controls the configuration of the ACM module. ACMCNF is cleared (0016) on reset.
Location: 00 FD4216
Type: R/W
Bit 76543210
Name Reserved OVUNSEL INTOUEN INTEMEN Reserved ACMMOD
Reset 00000000
Bit Description
1-0 ACMMOD (ACM Mode Control). Configures the operation mode of the ACM module. See “ACM Operating
Sequences” on page 211. This value becomes the active mode after writing a 1 to START bit in ACMCTS
register.
Bits
1 0 Description
0 0: ACM disabled (default)
0 1: Voltage Level Burst mode - single measurement of the voltage level for all the eight inputs
1 0: Threshold Comparison Burst mode - single comparison of all the eight inputs to the set threshold
1 1: Low-Power Threshold Comparison mode - periodic comparison of the inputs to a constant threshold
(recommended for Idle PC87591x operation mode). Its operation is stopped by the
selection of a different mode (ACM disabled = 002 is the recommended value).
2Reserved.
3INTEMEN (Interrupt from End-of-Measurement Event Enable). Enables generation of an ACM interrupt on an
End of Voltage Measurement Burst event (EOMEV in ACMCTS register).
0: Disabled (default)
1: Enabled - ACM Interrupt from EOMEV
4INTOUEN (Interrupt from Over/Under Threshold Event Enable). Enables generation of an ACM interrupt on
at least one input above (or below) the threshold event (OVUNTHEV ACMCTS register).
0: Disabled (default)
1: Enabled - ACM Interrupt from OVUNTHEV
5OVUNSEL (Over or Under Threshold Select). “Any Over” or “Any Under” logic selection for OVUNTHEV bit in
ACMCTS register.
0: At least one input below threshold sets OVUNTHEV=1 (default)
1: At least one input above threshold sets OVUNTHEV=1
7-6 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 215 www.national.com
PC87591E/S/L
ACM Timing Control Register (ACMTIM)
This register controls the sampling delay for the voltage level and compare out data; it also controls the division of the trigger
signal. ACMTIM is set to 3716 on reset.
Location: 00 FD4416
Type: R/W
Bit 76543210
Name Reserved T0DIV Reserved SMPDLY
Reset 0 0 110111
Bit Description
2-0 SMPDLY (Data Sampling Delay). Compensates for the settling time of the D/A converter and the input
comparators. To calculate the required delay value, see “Sampling Delay” on page 210.
Bits Settling Compare Max
2 1 0 Period1 Period1 Core Freq2
0 0 0: 1 10 5.5MHz
0 0 1: 1 15 8.5 MHz
0 1 0: 2 20 11.5 MHz
0 1 1: 2 25 14.2 MHz
1 0 0: 2 30 16.5 MHz
1 0 1: 2 35 20.0 MHz
1 1 0: 3 45 20.0 MHz
1 1 1: 3 55 20.0 MHz (default)
___________________________
1. The Settling and Compare periods are in clock cycles.
2. Conversion step time is equal to Settling Period + Compare Period
3Reserved.
5-4 T0DIV (Trigger Signal Division Factor). Controls the division of the T0IN trigger signal in Low Power Threshold
Comparison mode. A higher division factor gives a lower power consumption in Idle operation mode (see
Section 4.17 on page 235). T0IN frequency is separately set (see Section 4.10 on page 164).
Bits
5 4 T0In Division Factor
0 0: 16
0 1: 32
1 0: 64
1 1: 128 (default)
7-6 Reserved.
Embedded Controller Modules (Continued)
www.national.com 216 Revision1.07
PC87591E/S/L
Comparison Threshold Data Register (THRDAT)
This register holds the data used by the D/A converter in the threshold comparison modes. ACMCNF is cleared (0016)on
reset.
Location: 00 FD4616
Type: R/W
Comparison Result Register (CMPRES)
This register contains the result of the input comparison with the threshold.
Location: 00 FD4816
Type: RO
Bit 76543210
Name Reserved THRSHD5-THRSHD0
Reset 00000000
Bit Description
5-0 THRSHD5-THRSHD0 (Comparison Threshold Data). Data to be used by the D/A converter in Threshold
Comparison Burst and Low Power Threshold Comparison modes. All eight inputs are compared with the resulting
voltage value.
Range: 0 to 63 (0 to 63/64 *VCC); 6-bit, unsigned value with 1 LSB = VCC/64 (the value at reset is 0).
7-6 Reserved.
Bit 76543210
Name CMPIN7 CMPIN6 CMPIN5 CMPIN4 CMPIN3 CMPIN2 CMPIN1 CMPIN0
Bit Description
0CMPIN0 (Comparison Result for Input 0). Result of KBSIN0 comparison with the voltage threshold value.
Relevant only in Threshold Comparison Burst mode (ACMMOD = 102in ACMCNF register) and Low Power
Threshold Comparison mode (ACMMOD = 112). The value at reset is undefined.
0: Input below threshold
1: Input above threshold
1CMPIN1 (Comparison Result for Input 1). Same as CMPIN0 for KBSIN1.
2CMPIN2 (Comparison Result for Input 2). Same as CMPIN0 for KBSIN2.
3CMPIN3 (Comparison Result for Input 3). Same as CMPIN0 for KBSIN3.
4CMPIN4 (Comparison Result for Input 4). Same as CMPIN0 for KBSIN4.
5CMPIN5 (Comparison Result for Input 5). Same as CMPIN0 for KBSIN5.
6CMPIN6 (Comparison Result for Input 6). Same as CMPIN0 for KBSIN6.
7CMPIN7 (Comparison Result for Input 7). Same as CMPIN0 for KBSIN7.
Embedded Controller Modules (Continued)
Revision 1.07 217 www.national.com
PC87591E/S/L
Voltage Level Data Buffer - Input 0 through 7 (VOLDAT0-7)
This register holds the voltage level measurement result for inputs 0 through 7.
Location: 00 FD5016 - Input 0
00 FD5216 - Input 1
00 FD5416 - Input 2
00 FD5616 - Input 3
00 FD5816 - Input 4
00 FD5A16 - Input 5
00 FD5C16 - Input 6
00 FD5E16 - Input 7
Type: RO
4.14.6 Usage Hints
Voltage Level Burst
The total duration of the Voltage Level Burst measurement is a function of the system clock frequency (see Section 4.18 on
page 239) and the data sampling delay, selected by SMPDLY field in ACMTIM register. The values in Table 28 should only
be used to evaluate the maximum duration of the measurement. Actual duration may be shorter, depending on the input
level value. The software should use either EOMEV flag polling or the ACM interrupt, as described in Section 4.14.4 on
page 210.
Table 28. Voltage Level Burst Duration
Bit 76543210
Name Reserved VOLTLVL
Bit Description
5-0 VOLTLVL (Voltage Level Data). Voltage level of the respective input i (KBSINi for i 0 through 7), while operating
in Voltage Level Burst mode (ACMMOD = 012in ACMCNF register). The readout is an unsigned value with
1 LSB = VCC/64; the input voltage is calculated as: VIN = VOLTVL *(VCC/64).
7-6 Reserved.
System Clock Frequency
(MHz) SMPDLY Setting Maximum Burst Duration
(µs)
4 000 176
10 010 140
20 101 118
Embedded Controller Modules (Continued)
www.national.com 218 Revision1.07
PC87591E/S/L
4.15 ON-CHIP RAM
The PC87591x provides up to 4096-byte on-chip RAM array (2048-byte in PC87591E and PC87591L devices).
A 16-bit wide data bus links the core and the system RAM array. The system RAM can be byte or word accessed. Each
system RAM read or write operation is one cycle long and does not include any wait states. See Section 1.5.1 on page 33
for system RAM memory map.
4.16 ON-CHIP FLASH
The PC87591x has an on-chip flash memory device. This flash includes a Main Block, which serves as an on-chip Base
Memory, and an Information Block, which is used for device-specific parameters and user-defined data.
The Main Block (Base Memory) is used to store program and constant data of the core and/or host. In IRE and OBD envi-
ronments, the on-chip flash is used as (on-chip) Base Memory. In DEV environment, for easy and efficient code develop-
ment,theon-chipBase Memory is replaced by off-chip SRAM, which is referred to as off-chip Base Memory. See Section 1.4
on page 29 for more details about the memory emulation concept.
Note that in the PC87591L, the on-chip base memory is set to function as a ROM, with the associated limitations on write
and erase operations.
4.16.1 Features
Two flash memory blocks:
Main Block (Base Memory)
Information Block
Designated areas for:
Core boot code
Host boot code
Factory Parameters
Protection information
Supports flash operations:
Read (byte/word)
Write (byte/word)
Erase (page)
Several access paths for flash operations:
Core
Host
JTAG
Parallel Interface
Flash contents protection:
Different levels for each access path
Different levels for each memory block
Flash Timing Control for:
Command-based automatic control
Busy and error indicators
Low Power operation
Embedded Controller Modules (Continued)
Revision 1.07 219 www.national.com
PC87591E/S/L
4.16.2 Functional Description
The flash is byte accessible for reads and writes; it is erased in pages. Its organization is optimized for the PC87591x target
application and security needs. Table 29 summarizes the various flash size parameters.
Table 29. PC87591x Flash Organization
Flash Protection
The flash is partitioned into separate areas to protect the contents. Section 4.16.6 on page 226 provides details of the Main
Block and Information Block protection mechanisms, respectively. The main protected areas are:
Main Block
Core Boot Block - an area dedicated for the core boot code and protected from corruption by the CR or host.
Host Boot Block - an area dedicated for host boot code and protected from corruption by the host.
Other parts - optionally protected by software
Information Block
Factory Parameters - hold various parameters and calibration information defined during PC87591x production; pro-
tected from all alterations.
Protection Word - information about the flash data protection that may restrict accessing, writing and/or erasing all or
parts of the flash.
Other parts - software-controlled read and write protection.
Main Block (Base Memory) Information Block
Size1
1. See “Accessing Base Memory” on page 35 for the mapping of the memory blocks in the core address space.
Organization2
2. The memory width should be used for correct configuration of the BIU to enable cycle-by-cycle compatibility
between on-chip and off-chip Base Memory.
Page Size Access
Width AccessTime
Control Size Page Size Access
Width
64 Kbytes3
3. Block Size is 4 Kbytes only in PC87591L devices.
32Kx16
(Section 0) 512 bytes byte/word SZCFG1 64x16
(Section 0) 128 bytes byte/word
64 Kbytes4
4. This Main Block is available in PC87591S devices only.
32Kx16
(Section 1) 512 bytes byte/word SZCFG1 64x16
(Section 1) 128 bytes byte/word
Embedded Controller Modules (Continued)
www.national.com 220 Revision1.07
PC87591E/S/L
Access Paths
The flash memory can be read, written and erased through several access paths with different levels of protection for the
flash contents. Each of these paths can be operational in only some of the environments (i.e., IRE, OBD, DEV or PROG).
The flash access paths are:
Host interface
CR16B core
JTAG flash access
Parallel interface
Thehostand core use core bus read write transactions to access the flash. The JTAG and Parallel Interfaces have dedicated
access paths. An arbitration scheme selects the active interface that accesses the flash at any given time. The host and core
accesses may interleave. JTAG flash access is enabled in OBD and ENV environments when the appropriate enable bits
are set (see “Flash Interface Functional Description” on page 251 for the access enabling scheme). The Parallel interface
is enabled in PROG environment only.
Table 30 summarizes the flash information accessibility, the restrictions that apply in the various environments and the pro-
tection bit settings for each of the memory areas. Details of read, write and erase access are provided in Section 4.16.4 on
page 224. The following notation is used:
NA - Not accessible
RO - Read only
RW - Read, Write
RWE - Read, Write and Erase
RWe - Read, Write and a limited Erase (i.e., entire flash erase only).
Figure 76. On-Chip Flash Block Diagram
Arbitration
Protection
Timing
Access
Control
Shared BIOS
and
Security
Core Bus
JTAG I/F
Parallel I/Fs
Core
Main Block Information Block
To Host
Embedded Controller Modules (Continued)
Revision 1.07 221 www.national.com
PC87591E/S/L
Table 30. PC87591x Flash Read/Write/Erase Permission Matrix
Flash Page Organization and Erase Options
A flash erase operation changes all bits in the erased memory area to 1s. The minimum flash portion that can be erased is
a page. A byte address can be written once before the next erase.
The erase process includes verification. During an erase, a busy indicator is turned on. On completion, the busy indicator is
turned off, an error indicator is turned on if an error is detected and the on-chip flash returns to standby.
A flash program operation changes bits that are 1 to 0. A flash program operation may performed on bytes or words.
The PC87591x flash is organized in rows, grouped in pages and partitioned into sections as follows:
Table 31. PC87591x Section and Page Organization
The PC87591x provides three erase operations:
Page Erase - erase either one page of the flash Main Block or Information Block.
Section Erase - erase an entire section.
Special Erase - erase the entire flash (except factory parameters).
Notes:
The high voltage required for flash operation is generated on-chip from VCC.
Flash endurance: 10,000 write-erase cycles (minimum).
The PC87591L flash is guaranteed for five write-erase cycles only.
Data retention: more than 100 years at room temperature.
Memory Area Interface Host1
1. Additional read and/or write protection may apply according to the setting of the software
controlled protection mechanism.
Core JTAG2
2. Read and write operations are enabled only if the Flash Access Enable bit (FLAEN in
FL_CT_ST register) is 1 (see page 262). When the Flash Access Enable bit is cleared,
only a special erase may be performed.
Parallel I/F2
Environment IRE, OBD & DEV OBD & DEV PROG
Main Block
(Base Memory) Core Boot Block NA3
3. In DEV Environment, the Base Memory is implemented using an off-chip SRAM, thus any
access by the core and/or host is routed to it. Host access limitations apply in DEV envi-
ronment. The core is allowed full read and write access to the off-chip Base Memory.
RO3RWE RWE
Host Boot Block RO3RWE3RWE RWE
Other RWE3RWE3RWE RWE
InformationBlock Factory Parameters NA RO RO RWE
Protection Word NA RO RWe RWe
Block Section Name Address Range Page Size
Main Block Section 01
1. In the PC87591L, the main block is in addresses 00 000016 - 000FFF16.
00 000016 - 00 FFFF16 512 bytes
Section 12
2. Available only in the PC87591S.
01 000016 - 01 FFFF16 512 bytes
Information Block Section 0 00016 - 07F16 128 bytes
Section 1 08016 - 0FF16 128 bytes
Embedded Controller Modules (Continued)
www.national.com 222 Revision1.07
PC87591E/S/L
Flash Read, Write and Erase Time
The flash read access time affects the performance of the core. It is therefore recommended to configure the interface to
achieve the maximum performance allowed for the operation frequency. Table 32 lists the access time for each section of
the flash.
Notes:
Write cycle timing is not cycle-by-cycle emulated for off-chip Base Memory (SRAM).
For fast read operation, the respective BIU zone should be configured for fast read.
For n wait states, the respective BIU zone should be configured for normal read with n wait states. This provides an
n+2 cycles read throughput.
Sections 0 and 1 are also referred to as the Fast zone.
The Flash Timing Control, included as part of the PC87591x on-chip flash, controls the access time for read, write and erase
operations of the flash memory. This simplifies the handling and use of the flash by the user. To enable operation with var-
ious clock rates the Flash Timing Control includes a set of registers that enable the core to set the parameters. For more
details on the Flash Timing Control, see Section 4.16.3 on page 222.
4.16.3 Flash Interface States and Timing Control
The Flash Timing Control automates six states: Standby, Read, Program, Page Erase, Section Erase and Special Erase.
The widths of pulses used in flash operation are specified in registers and should be set by software based on the operation
frequency of the core clock.
Standby State
The flash does not perform a read, program or erase operation. This is the default state when no operation is per-
formed; current consumption of the flash is therefore minimal.
Read State
The flash performs a read operation from either the Main Block or the Information Block. Host or core reads
through the core bus are extended to the required length based on the BIU SZCGF1settings. JTAG interface ac-
cess uses a busy flag to indicate that the read operation is in progress. When the read is completed, the flash re-
turns to Standby state.
Program State
The flash programs a byte or word in either the Main Block or Information Block. This state is entered by a core or
host write (with the Program control bit set) or by a JTAG program command. While in this state, the busy indicator
is set. When the program operation is completed, if the verify is enabled, the data is verified and the error bits are
updated accordingly. During Program state, reset is ignored. During programing of the flash, additional writes to
the flash are ignored and reads are delayed until the flash page programing is completed.
Page Erase State
The Page Erase state is entered by a core or host write or by a JTAG command when the Page Erase bit is set. An
address within the page specifies which page is to be erased. While in this state, the busy indicator is set. When
the erase operation is completed and the verification is enabled, the data is verified and the error bits are updated
accordingly. During Page Erase state, reset is ignored, additional writes to the flash are ignored and reads are de-
layed until the flash page erase is completed.
Section Erase State
The Section Erase state is entered by a core write or by a JTAG command when the Section Erase bit is set. An
address within the section specifies which section is to be erased. While in this state, the busy indicator is set.
When the erase operation is completed, the data is verified and the error bits are updated accordingly. During Sec-
tion Erase state, reset is ignored, additional writes to the flash are ignored and reads are delayed until the flash
section erase is completed.
Table 32. Access Time for Flash Sections
Block Name Section Number Max Frequency1,2
1. See Section 7.5 on page 381 for the values of these parameters.
2. The Zone Configuration register SZCFG1 should be used to set the access speed, based on the cur-
rent operation speed and minimum required access time.
Write Time Erase Time
Main Block Sections 0 and 1 FFMAX @ fast read Approx. 20 µs,
as defined in Table 33 Approx. 10 ms,
as defined in Table 33
Information Block Sections 0 and 1 FFMAX @ 3 clock cycles Approx. 10 ms,
as defined in Table 33
Embedded Controller Modules (Continued)
Revision 1.07 223 www.national.com
PC87591E/S/L
A write to an address within a Main Block section results in an erase of the Main Block section. A write to an ad-
dress within an Information Block section results in an erase of the Information Block section and its corresponding
Main Block section (e.g., Main Block section 0 and Information Block section 0).
Special Erase State
The Special Erase state is entered by a command from JTAG. Special erase enables erasing the entire flash, ex-
cept for the factory parameters. It is the only operation on the flash enabled for the JTAG when the flash protection
field is set to Protect. While in this state, the busy indicator is set. When the erase operation is completed, the data
is verified and the error bits are updated accordingly. During Special Erase state, reset is ignored. The protected
data information is always the last to be erased.
Both program and erase can be initiated by the host, core or JTAG interface. Note that no instruction fetch or data read/write
can be performed from/to the on-chip flash while it is being programed or erased.
While the JTAG Flash interface is enabled, the Debugger interface generates a reset, which causes the core, the Host in-
terface circuit and the core bus to be held in reset.
Flash Operation Timing Control
The Information Block read, the program and erase timings are controlled by internal timers. (The read timing from the Main
Block is controlled by the BIU configuration). The timers default on Power-Up reset to operate at a core frequency of 4 MHz.
Software may change this for operation with other core clock frequencies.
Section 4.16.7 on page 228 lists the timing control registers. Table 33 provides the values that should be programed into
the control registers for each core domain clock frequency. It is the responsibility of the firmware to make sure that the timing
control registers are set according to the current core domain clock frequency before any flash erase or flash program is
allowed.
Reset
While the on-chip flash is in Read state, driving reset aborts the current operation. Flash program and Erase operations con-
tinue to completion and the reset is extended accordingly. If reset is applied during Program or Erase state, the contents of
memory are not guaranteed (i.e., the program or erase may fail).
After reset, the on-chip flash defaults to Standby state.
When JTAG access to flash is disabled, the Flash interface is reset by all reset events. When the JTAG access to flash is
enabled, the PC87591x is reset, but the Flash interface allows flash access after all of the following have occurred:
The core clocks are stable in their default setting.
The protection information has been read.
Default values have been loaded into the Flash Interface registers.
On exiting from “JTAG Access to Flash” mode, the Flash Interface module is reset again (i.e., protection information is read
and default values loaded into the Flash Interface registers)
Table 33. Control Registers Values per Core Domain Clock
Core Domain
Clock FLPSLR FLSTART FLTRAN FLPROG FLPERASE FLSERASE FLEND FLSEND FLRCV
[MHz] [hex] [hex] [hex] [hex] [hex] [hex] [hex] [hex] [hex]
4 0 14 28 A 9 9 14 32 4
5 0 19 32 C C C 19 3E 5
6 0 1E 3C F E E 1E 4B 6
7 0 23 46 11 11 11 23 57 7
8 0 28 50 14 13 13 28 64 8
9 0 2D 5A 16 16 16 2D 70 9
10 1 19 32 C C C 19 3E 5
12 1 1E 3C F E E 1E 4B 6
20 3 19 32 C C C 19 3E 5
Embedded Controller Modules (Continued)
www.national.com 224 Revision1.07
PC87591E/S/L
Pipelined Programing Cycles
Pipelined programing uses a word-wide double-buffer (for Main Block accesses) or a byte-wide double-buffer (for Informa-
tion Block accesses). Accesses should be word-wide or byte-wide, correspondingly; otherwise, results are undefined.
When the double-buffer is empty, the pipelined programing is initiated on a valid byte/word write to the on-chip flash. The
address of the transaction is the starting address. The Flash Timing Control automatically increments the address for the
next write to point to the next byte/word.
Pipelined programing is completed when the double-buffer is empty or on reaching the highest address within the row. On
completion, the busy indicator is turned off, any data in the double-buffer is discarded, an error indicator is turned on if an
error is detected, and the on-chip flash returns to standby.
Results are undefined when Main Block and Information Block accesses are interleaved while the double-buffer is notempty.
Low Power Read Operation Mode
The PC87591x supports low power read operation for the on-chip flash. When this is enabled (see “Flash Memory Control
Register (FLCR)” on page 230), single core bus cycle read accesses consume less power. Low power operation may be
enabled only when the core clock is below the following limit:
Below FMAX for Sections 0 and 1 controlled by LOWPWRF bit
4.16.4 Flash Access and Control
The flash may be accessed for read, program and erase of data in either the Main Block or Information Block. This section
describes the activities required to enable any of the operations from each of the access paths (Core, Host, JTAG).
Before an access path to the flash may be used, the PC87591x must be in a state that enables that path:
Core and Host Interface - Active in IRE, OBD or DEV environment (Information Block only for DEV environment).
For host write operations, the host must gain control of the flash (HLOCK bit in SMCCST register must be set).
Any access (read or write) protection may override the requested access.
JTAG Interface - OBD or DEV environments with the JTAG Flash interface enabled.
Section 4.19 on page 248 provides details of the JTAG flash access. Section 4.16.5 on page 226 provides details of the
PROG environment bus. For all interfaces, read, program and erase protection flags may prevent the operations described
from being completed.
Note that during Erase and Program of the flash, an access to the flash is handled as follows:
Core read is delayed to the end of the read.
Core write to the Main Block or Information Block is ignored.
Core write to IBAI register is ignored.
Host reads or writes are ignored by the Flash interface and restarted by the host once the flash program/erase is
completed.
If core activity is required during flash program or erase, make sure it executes from RAM or external memory before the
flash erase/programing begins.
Main Block Read
When the flash is not busy, read operations return the data in the accessed on-chip flash address. Either byte or word may
be read.
The SZCFG1 register defines the number of core bus cycles used to access Base Memory (see Section 4.1.11 on page 86
and “Static Zone Configuration Register (SZCFGn)” on page 85 for further details). The number of cycles that each access
requires, for each one of the zones, is defined in “Flash Read, Write and Erase Time” on page 222.
If the BIU configuration is identical in all environments, the access time to the on-chip flash Main Block and off-chip Base
Memory, for read operations, is the same. This allows cycle-by-cycle compatibility in IRE, OBD and DEV operating environ-
ments.
Information Block Read
Information Block data is read using an indirect access scheme. This information may be read by the core, through the JTAG
Interface or the Parallel Interface.
The core accesses the Information Block using indirect byte/word read access. To read from the Information Block:
The byte or word address must be stored in IBAI register (note that Information Block addresses are mapped from
000 as shown in Table 31 on page 221).; word addresses must be even.
Data byte/words must be read using a byte/word read operation from BD register.
The JTAG performs a read operation with an Information Block address attribute set. Only word read is allowed.
Embedded Controller Modules (Continued)
Revision 1.07 225 www.national.com
PC87591E/S/L
Main Block Page Erase
Pages in the Main Block may be erased one at a time. The size of the pages are defined in Table 30 on page 221 and “Flash
Read, Write and Erase Time” on page 222. To enable erasing by the core or host, the page must be enabled for write.
1. Verify that the flash is not busy.
2. Prevent access to the flash while erase is in progress, if required.
3. Set the page erase bit.
4. Write to an address in the desired page.
5. Wait until the busy bit is cleared and check the error flags to see if the erase was successful.
6. To erase additional pages, repeat steps 3 through 5.
7. Clear the page erase bit to prevent accidental erase operations.
To erase a page using the JTAG interface, see Section 4.19.4 on page 251.
Information Block Page Erase
Pages in the Information Block may be erased one at a time. The size of the pages are defined in Table 30 on page 221 and
Table 31 on page 221. Note that the factory parameters and the protection information may not be updated by the core.
To erase a page using the JTAG interface, see Section 4.19.4 on page 251. Note that the Factory Parameters page may
not be erased by the JTAG interface.
Main Block Section Erase
Sections in the Main Block may be erased with a single erase operation. The size of the sections are defined in Table 30 on
page 221 and Table 31 on page 221. To enable an erase by the core, the entire section must be enabled for write. Note that
Host-initiated section erases are not allowed.
1. Verify that the flash is not busy.
2. Prevent access to the flash while erase is in progress, if required.
3. Set the section erase bit in the control register (SMER bit in FLCR register).
4. Write to an address in the desired section.
5. Wait until the busy bit is cleared and check the error flags to see if the erase was successful.
6. To erase additional sections, repeat steps 3 through 5.
7. Clear the section erase bit (SMER bit in FLCR register) to prevent accidental erase operation.
To erase a page using the JTAG interface, see Section 4.19.4 on page 251.
Main and Information Block Section Erase
Sections in the Main Block and Information Block may be erased simultaneously using a single erase operation. The size of
the sections are defined in Table 30 on page 221 and Table 31 on page 221. To erase a section using the JTAG interface,
see Section 4.19.4 on page 251.
Special Erase
This operation is enabled only for the JTAG interface. If the Flash Contents Protection bit is set, this operation should be
done to enable any other access to the flash (or to enable the Debugger interface functions).
To perform a special erase using the JTAG interface, see Section 4.19.4 on page 251.
Program the Main Block
The program operation enables changing bits with a value of 1 to 0. Each byte address of the Main Block may be programed
once before being erased. If required, perform an erase operation prior to the program operation. To program a byte in the
Main Block:
1. Verify that the flash is not busy.
2. Prevent access to the flash while the program operation is in progress, if required.
3. Set the program bit in the control register (PE bit in FLCR register).
4. Write to the byte or word that needs to be programed.
5. Wait until the busy bit is cleared and check the error flags to see if the program operation was successful.
6. To program additional bytes/words, repeat steps 3 through 5.
To program a byte or word using the JTAG interface, see Section 4.19.4 on page 251.
Embedded Controller Modules (Continued)
www.national.com 226 Revision1.07
PC87591E/S/L
Program a Page in the Information Block
The program operation enables changing bits with a value of 1 to 0. Each byte address of the Information Block may be
programed once before being erased. If required, perform an erase operation prior to the program operation.
To program a word using the JTAG interface, see Section 4.19.4 on page 251.
4.16.5 Parallel Flash Interface
The Parallel Flash interface used in PROG environment allows the PC87591x to be tested and programed quickly with Au-
tomated Test Equipment (ATE) and programers in the OEM’s manufacturing flow.
For details about this interface, contact a National Semiconductor sales representative.
4.16.6 Flash Protection
The Main Block can be accessed by the core, host, JTAG interface and Parallel interface. The Information Block may be
accessed by the core, JTAG interface and Parallel interface. A protection mechanism that combines hardware and software
controlled elements is provided. The protection level depends on the access path used and the contents of the ‘protection
word’.
Protection Word
The protection word is stored in address 0FE16 in the flash Information Block. It is constructed as follows:
Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Name Res RST2EN Reserved Flash Contents
Protect
Force
MBTA
Zero
RTC Lock
Default Host Boot
Block Core Boot Block
Bit Description
3-0 Core Boot Block. Defines the size of the Core Boot Block
The boot block starts at address 00 0000 and ends at the address specified by this field.
Bits
3 2 1 0 Description
1 1 1 1: Flash is erased. When in IRE and OBD environments, the core is kept in reset (default).
1 1 1 0: 4K
1 1 0 1: 8K
1 1 0 0: 16K
1 0 1 1: 24K
1 0 1 0: 32K
1 0 0 1: 40K
1 0 0 0: 48K
0 1 1 1: 56K
0 1 1 0: 80K
0 1 0 1: 96K
0 1 0 0: 112K
0 0 1 1: 128K
Other: Reserved
4Host Boot Block. Defines the use and the size of a Host Boot Block area. The Host Boot Block is always at
the end of the on-chip flash memory. Protection is provided by the Shared Memory function.1
0: A 64 Kbyte Host Boot Block is specified
1: No Host Boot Block is available (default)
Embedded Controller Modules (Continued)
Revision 1.07 227 www.national.com
PC87591E/S/L
The protection word is read by hardware from the Information Block during the internal reset process. This information is
used to set the host access restrictions described in Section 5.3.5 on page 301, the core access restrictions defined in this
section, and the JTAG access protection described in OBD and PROG environment access restrictions; see Table 30 on
page 221.
There is no protection over the core’s reading the flash contents. Writes to a write-protected page are ignored. When en-
abled, a core interrupt may be generated on write-protect violations.
Core-Initiated Accesses
There is no read protection on core-initiated read accesses. Write protection is provided with default settings and firmware
override as follows:
Main memory block - per 8 Kbyte block
Information Block Factory parameters and protection word are always write protected
This protection is defined using FCWP0 register. All blocks are defined as write protected on reset. The blocks within the
Core Boot Block and Host Boot Block are read only (RO) to prevent accidental alteration of their contents by the core.
Special Erase state is not supported for core-initiated accesses.
Host-Initiated Accesses
Host access to the flash Main Block is controlled by the information in the protection word and is controlled and further re-
stricted by the core. Section 5.3.5 on page 301 details the host access limitations. The host may not access the Information
Block.
5RTC Lock Default. Defines the reset value of the Lock RTC Host Access (LKRTCHA) bit in the Lock SuperI/O
Host Access register (LKSIOHA). This enables preventing host access to the RTC at any time when the RTC is
used by security applications running on the core.
0: RTC Lock is disabled on reset (LKRTCHA=0)
1: RTC Lock is enabled on reset (LKRTCHA=1) (default)
6Force MBTA Zero. Enables the setting of the host boot block location to either end of on-chip flash or to the
expansion memory1. See “Shared Memory Core Top Address Register (SMCTA)” on page 308.
0: MBSD field in SMCTA register is reset to the implemented on-chip flash size
1: MBSD field in SMCTA register is reset to 000016 (default)
9-7 Flash Contents Protect. Enables protecting the contents of the on-chip flash from probing through the JTAG
interface or Parallel interface.
Bits
9 8 7 Description
1 1 1: Flash access is enabled for both read and write
Other: Flash access is protected. In any environment other than IRE, the device remains reset.
In OBD and DEV environments, only
special erase through the JTAG interface is enabled.
12-10 Reserved.
14-13 RST2EN (RESET2 Enable). Controls the use of the RESET2 alternate function. The following options are
supported in the PC87591x:
Bits
15 14 Description
0 0: Reserved
0 1: RESET2 is enabled on the IOPB7/RING/PFAIL/RESET2 pin
1 0: RESET2 is enabled on the IOPD2/EXWINT24/RESET2 pin
1 1: RESET2 input is disabled, and RESET2 events will not be generated (default)
15 Reserved.
1. When expansion memory is used for a shared BIOS implementation, set the Force MBTA Zero bit to 0, do not
clear the Host Boot Block bit, and use a flash device with a boot block as expansion memory.
Bit Description
Embedded Controller Modules (Continued)
www.national.com 228 Revision1.07
PC87591E/S/L
JTAG-Initiated Accesses
JTAG-initiated accesses for both read and write is restricted based on the value held in the Flash Contents Protect field of
the protection word.
When any bit in the Flash Contents Protect field is 0, no reads or writes are allowed. In OBD or DEV environment, the device
remains reset until a special erase is performed. The only operation allowed in this case is a special erase of the flash con-
tents.
When all bits in the Flash Contents Protect field are 1, all flash operations are allowed. The entire flash may be read, and
except for the Factory Parameters page Of the Information Block, the entire flash may be erased and programed.
Parallel Flash Interface-Initiated Accesses
Parallel Flash interface-initiated accesses are subject to the same protection scheme as JTAG-initiated accesses. When
any bit in the Flash Contents Protect field is 0, only special erase operations are allowed and all other flash access opera-
tions are ignored.
See also Section 4.16.5 on page 226.
4.16.7 Flash Interface Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
Information Block Access Index Register (IBAI)
This register defines the address bits 7-0 for read or write transaction to the Information Block.
Location: 00 F88016
Type: R/W
Table 34. Flash Interface Register Map
Mnemonic Register Name Type
IBAI Information Block Access Index R/W
IBD Information Block Data R/W
FCWP0 Flash Core Write Protect R/W
FLCR Flash Memory Control R/W
FLSR Flash Memory Status R/W1C
FLPSLR Flash Memory Pre-Scaler R/W
FLSTART Flash Memory Start Time R/W
FLTRAN Flash Memory Transition Time R/W
FLPROG Flash Memory Program Time R/W
FLPERASE Flash Memory Page Erase Time R/W
FLSERASE Flash Memory Section Erase Time R/W
FLEND Flash Memory End Time R/W
FLSEND Flash Memory Section Erase End Time R/W
FLRCV Flash Memory Recovery Time R/W
Bit 1514131211109876543210
Name Reserved Indirect Memory Address 7-0
Bit Description
7-0 Index Address 7-0. The address is of a byte address in the flash Information Block. Access to words is allowed
only to word-aligned addresses.
15-8 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 229 www.national.com
PC87591E/S/L
Information Block Data Register (IBD)
This register holds the data for read or write transaction from/to the Information Block. Byte or word reads and writes to this
register are allowed to access a byte or word pointed to by IBA register. Note the program and erase limitations imposed by
the flash protection scheme.
Location: 00 F88216
Type: R/W
Flash Core Write Protect Register 0 (FCWP0)
This register controls write protection of the Main Block per 8 Kbyte blocks. It is cleared (0016) on reset.
Location: 00 F89016
Type: R/W
Bit 1514131211109876543210
Name Information Block Data
Bit Description
15-0 Information Block Data.
Bit 1514131211109876543210
Name FC0WP15-0
Reset 0000000000000000
Bit Description
15-0 Core Write Protect. Each bit controls an 8 Kbyte block.
For bit i, the block’s start address is i x 00 200016.
0: Program and erase are inhibited for this block
1: Program and erase are allowed for this block
Bits within the Core Boot Block and Host Boot Block, as defined by the protection word, are ignored, and the
flash memory is always write protected.
Embedded Controller Modules (Continued)
www.national.com 230 Revision1.07
PC87591E/S/L
Flash Memory Control Register (FLCR)
This register controls the on-chip flash operation modes. It is cleared (0016) on reset. The core can write this register only
when HLOCK bit in SMCCST register is 0 (see Section 5.3.9 on page 307). Otherwise, writes are ignored.
Location: 00 F8C016
Type: R/W
Bit 76543210
Name SMER PMER PE IENPROG Reserved LOWPWR
Reset 00000000
Bit 15 14 13 12 11 10 9 8
Name Reserved DISVRF
Reset 00000000
Bit Description
0LOWPWR (Low Power Mode).
0: On-chip flash is in Normal mode
1: On-chip flash is in Low Power mode
This bit may be set (1) only when the core domain’s clock is up to fFLPMAX.
It may be altered only when FRE bit in SZCFG1 register is set (1).
3-1 Reserved.
4IENPROG (Interrupt Enable for Program).
0: Interrupt request disabled.
1: An interrupt request to the ICU is enabled (see FMLFULL in the Flash Memory Status register).
5PE (Program Enable). This bit is impact core program operations only.
0: Flash Programing is disabled (default)
1: Flash Programing is enabled (if PMER and SMER are cleared)
6PMER (Page Erase). When set (1) a valid write to the on-chip flash erases the entire page pointed to by the
write address. This bit affects core erase operations only.
This bit may be modified, only when the FMBUSY bit is cleared (0); otherwise, results are undefined.
0: Flash Page Erase is disabled (default)
1: Flash Page Erase is enabled (if PE and SMER are cleared).
7SMER (Section Erase). When set (1), a valid write to the on-chip flash erases the entire section pointed to by
the write address.
Write to a Main Block address results in a Main Block section erase.
Write to an Information Block address results in an Information Block section and its corresponding Main Block
section erase. This bit affects core erase operations only.
This bit may be modified only when the FMBUSY bit is cleared (0); otherwise, results are undefined.
0: Flash Section Erase is disabled (default)
1: Flash Section Erase is enabled (if PMER and PE are cleared).
8DISVRF (Disable Verify). This bit affects core program and erase operations only.
0: Verify flash contents after program or erase is enabled (default).
1: Disable the automatic verification of flash contents after program or erase.
This speeds up the program or erase speed.
15-9 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 231 www.national.com
PC87591E/S/L
Flash Memory Status Register (FLSR)
This register provides the on-chip flash status. It is cleared (0016) on reset.
Location: 00 F8C216
Type: Varies per bit
Flash Memory Pre-Scaler Register (FLPSLR)
The FLPSLR register selects the pre-scaler divider ratio. FLPSLR defaults to (0016) on reset.
Location: 00 F8C416
Type: R/W
Bit 76543210
Name Reserved DERR FMLFULL FMBUSY PERR EERR
Reset 00000000
Bit Type Description
0 R/W1C EERR (Erase Error). Indicates an error in erasing the flash by the core. It is cleared by writing 1 to it.
Writing 0 is ignored. This bit may be cleared only when the FMBUSY bit is cleared (0).
0: No program error detected (default)
1: An error occurred during erase
1 R/W1C PERR (Program Error). Indicates an error in writing to the flash by the core. It is cleared by writing 1
to it. Writing 0 is ignored. This bit may be cleared only when the FMBUSY bit is cleared (0).
0: No program error detected (default)
1: An error occurred during program
2ROFMBUSY.
0: The embedded flash is ready to accept operations
1: The embedded flash is not accessible since the PC87591x clocks are not ready or the embedded flash
is busy programing or erasing
3ROFMLFULL (Double-Buffer Full). Indicates that the core can not write to the flash since its buffer is full.
0: There is at least one word empty in the flash double buffer. If IENPROG is set (1), in the Flash Memory
Control register, an interrupt request to the ICU is active.
1: The double-buffer is full
4 R/W1C DERR (Data Loss Error). Indicates that a double-buffer overrun error has occurred during core access.
It is cleared by writing 1 to the DERR bit. Writing 0 is ignored. This bit may be cleared only when the
FMBUSY bit is cleared (0).
0: No data loss detected (default)
1: A write to a full buffer was detected
7-5 Reserved.
Bit 76543210
Name Reserved FTDIV
Reset 00000000
Bit Description
3-0 FTDIV (Pre-Scaler Divider Value). This register should be configured based on the currently set core
frequency. See Table 33 on page 223 for details of required values.
7-4 Reserved.
Embedded Controller Modules (Continued)
www.national.com 232 Revision1.07
PC87591E/S/L
Flash Memory Start Time Register (FLSTART)
The FLSTART register controls the program/erase start delay time. FLSTART defaults to (1416) on reset.
Location: 00 F8C616
Type: R/W
Flash Memory Transition Time Register (FLTRAN)
The FLTRAN register controls some program/erase transition timings. FLTRAN defaults to (2816) on reset.
Location: 00 F8CA16
Type: R/W
Flash Memory Program Time Register (FLPROG)
The FLPROG register controls the programing pulse width. FLPROG defaults to (0A16) on reset.
Location: 00 F8D016
Type: R/W
Bit 76543210
Name FTSTART
Reset 00010100
Bit Description
7-0 FTSTART (Start Delay Count). This register should be configured based on the currently set core frequency.
See Table 33 on page 223 for required values.
Bit 76543210
Name FTTRAN
Reset 00101000
Bit Description
7-0 FTTRAN (Transition Count). This register should be configured based on the currently set core frequency. See
Table 33 on page 223 for details of required values.
Bit 76543210
Name FTPROG
Reset 00001010
Bit Description
7-0 FTPROG (Programing Pulse Width). This register should be configured based on the currently set core
frequency. See Table 33 on page 223 for details of required values.
Embedded Controller Modules (Continued)
Revision 1.07 233 www.national.com
PC87591E/S/L
Flash Memory Page Erase Time Register (FLPERASE)
The FLPERASE register controls the page erase pulse width. FLPERASE defaults to (0916) on reset.
Location: 00 F8D216
Type: R/W
Flash Memory Section Erase Time Register (FLSERASE)
The FLSERASE register controls the section erase pulse width. FLSERASE defaults to (0916) on reset.
Location: 00 F8D416
Type: R/W
Flash Memory End Time Register (FLEND)
The FLEND register controls the program/page erase end delay time. FLEND defaults to (1416) on reset.
Location: 00 F8D816
Type: R/W
Bit 76543210
Name FTPER
Reset 00001001
Bit Description
7-0 FTPER (Page Erase Pulse Width). This register should be configured based on the currently set core
frequency. See Table 33 on page 223 for details of required values.
Bit 76543210
Name FTSER
Reset 00001001
Bit Description
7-0 FTSER (Section Erase Pulse Width). This register should be configured based on the currently set core
frequency. See Table 33 on page 223 for details of required values.
Bit 76543210
Name FTEND
Reset 00010100
Bit Description
7-0 FTEND (End Delay Count). This register should be configured based on the currently set core frequency. See
Table 33 on page 223 for details of required values.
Embedded Controller Modules (Continued)
www.national.com 234 Revision1.07
PC87591E/S/L
Flash Memory Section Erase End Time Register (FLSEND)
The FLSEND register controls the section erase end delay time. FTSEND defaults to (3216) on reset.
Location: 00 F8DC16
Type: R/W
Flash Memory Recovery Time Register (FLRCV)
The FLRCV register controls the recovery time required between two accesses. FTRCV defaults to (0416) on reset.
Location: 00 F8DE16
Type: R/W
Bit 76543210
Name FTSEND
Reset 00110010
Bit Description
7-0 FTSEND (Section Erase End Delay Count). This register should be configured based on the currently set core
frequency. See Table 33 on page 223 for details of required values.
Bit 76543210
Name FTRCV
Reset 00000100
Bit Description
7-0 FTRCV (Recovery Time). This register should be configured based on the currently set core frequency. See
Table 33 on page 223 for details of required values.
Embedded Controller Modules (Continued)
Revision 1.07 235 www.national.com
PC87591E/S/L
4.17 POWER MANAGEMENT CONTROLLER (PMC)
The Power Management Controller (PMC) module improves the efficiency of PC87591x operation by adjusting the chip’s
power consumption to the level of activity required by the application. This module works together with the High-Frequency
Clock Generator (HCFG) and the core to control the activity of the PC87591x. It also interacts with the Multi-Input Wake-Up
(MIWU), Interrupt Control Unit (ICU) and Debugger interface for wake-up events.
4.17.1 Features
Three core domain power modes:
Active
Idle
Power Off
Two clock inputs:
High-frequency clock (HFCLK)
Low-frequency clock (LFCLK)
Power mode switching by software and/or hardware control
High-frequency clock source Enable/Disable control
Other core domain modules are controlled with power mode indications
4.17.2 The Core Domain Power Modes
Table 35 summarizes the main properties of the three modes and shows the activity levels of clocks while in the various
power states.
Table 35. Core Domain Power Mode Summary
Active Mode
In Active mode, the core domain operates at the frequency generated by the HFCG. This frequency may be changed dy-
namically using the Load, Fast, Load96 or Fast96 operations in the HFCG module. The module’s respective enable/disable
bits control module activity.
In this mode, power consumption can be reduced by selectively disabling modules and/or by the core executing the WAIT
instruction. When WAIT is executed, the core stops executing new instructions until it receives an interrupt signal.
After reset, the PC87591x is in Active mode.
Idle Mode
In Idle mode, the clock is stopped for most of the core domain. Only the PMC and a limited number of core domain modules
(such as the TWD) continue to operate at the low-frequency oscillator rate; they can wake up the core domain and resume
instruction execution when required.
For modules that are active in Idle mode, details of their activity are included in the module’s description.
Wake-up events are generated by the MIWU module according to the enabled internal and external events.
Power Off Mode
When VCC power is turned off, the core domain reaches its lowest activity level. The contents of the memories (except for
the on-chip flash) and registers are not preserved in this mode. Applying power to the core domain should be done using
the VCC power-up reset sequence.
Mode HFCG LFCG CLK LFCLK1
1. The RTC and TWM modules always work from the LF oscillator.
VCC Supply
Active2
2. The core may execute the WAIT instruction while in Active mode to reduce power con-
sumption while no core activity is required. This state is referred to as “Active Executing
WAIT” in some places in the specification, but it is not a separate power state as far as
clocks are concerned.
On On HF LF On
Idle On or Off3
3. Can be turned off by software but depends also on SuperI/O clock domain activation.
On Off LF On
Power Off Off On Off Off Off
Embedded Controller Modules (Continued)
www.national.com 236 Revision1.07
PC87591E/S/L
A battery supply pin (VBAT) provides power to the RTC and low-frequency clock oscillator (LFCO), allowing these parts to
continue functioning even in Power Off mode. Some registers are reserved and events recorded. These registers and events
are maintained by VPP, as noted.
Details of the activity of each battery-operable module are provided in the module’s specification.
4.17.3 Switching Between Power Modes
The switching from one power mode to another is done using the protocols described below.
Figure 77 shows the three power modes of the core domain and the transitions between them.
Wake-Up Event
Some of the power-up switchings are based on receiving a wake-up event. This event has three possible sources:
A maskable event (from MIWU)
A Non-Maskable Interrupt (NMI)
An ISE interrupt (from the Debugger interface)
The wake-up is identified by a high level on the maskable event and/or a low-to-high transition on NMI or ISE interrupts.
Once a wake-up event is detected, it is latched until an interrupt acknowledge bus cycle is detected or a reset is applied.
Decreasing Power Consumption
Entering Idle Mode
Enter Idle mode by setting (1) IDLE bit in PMCSR register and then executing the WAIT instruction. WBPSM must be set
before executing WAIT.The HFCG may be disabled to further reduce the power consumption. This is done by writing 1 to
DHF in PMCSR register before executing WAIT.
Entering Power Off Mode
Switch to Power Off mode by turning off the supply to the VCC pins of the PC87591x Note that VDD must be turned off as well.
The PFAIL input may be used to interrupt the PC87591x so that context saving to a non-volatile memory can be completed
and write operations to the RTC can be stopped before the power to the PC87591x is disconnected.
Increasing Activity
Fast Wake-Up from Idle Mode to Active
Ahardwarewake-upevent causes the core domain to switch directly from Idle mode to Active mode. The following sequence
is performed:
1. HDF in PMCSR register is cleared, thus enabling the high-frequency clock (if it was disabled).
2. After waiting for the high-frequency clock to become active (OHFC in PMCSR register is set), the core domain switches
to Active mode.
When in Active mode, Idle bit in PMCSR register is cleared.
Active
Idle
Power Off
Turn off supply
IDLE =1
and WAIT
Turn on power
apply reset
HW event
supply and
Reset
Figure 77. Power Modes and Transitions
Embedded Controller Modules (Continued)
Revision 1.07 237 www.national.com
PC87591E/S/L
If the core was executing a WAIT instruction, it resumes operation by entering an interrupt routine (an enabled interrupt in
the ICU, NMI or ISE).
Exit from Power Off
When in Power Off, activity can be resumed only by switching to Active mode. This is done by applying VCC power to the
PC87591x. The Power-Up reset sequence described in “VCC Power-Up Reset” on page 66 should be applied.
Power Mode Switch Protection
The PMC module includes a mechanism that protects the PC87591x from malfunctions caused by missing or unstable clock
signals.
Clock Toggling Indication
OHFC and OLFC bits in PMCSR register indicate the current status of the high- and low-frequency clock inputs, respectively.
The current status is based on indications from the HFCG and LFCG modules.
ThePMCdoesnotusethehigh-frequencyclockwhenthe OHFCbit is 0; it does not use the low-frequency clock when OLFC is 0.
During reset, the PC87591x clock does not toggle until OHFC is 1. During power mode change, if there is a request to switch
to a non-stable or non-toggling clock, the power mode change stalls.
4.17.4 The Power Management Controller Status Register (PMCSR)
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
PMCSR is a byte-wide, read/write register that selects the Active or Idle modes. In addition, it controls the operation of the
HFCG by enabling or disabling the high-frequency core clock domain. On reset, all non-reserved bits are cleared. PMCSR
format is shown below.
Location: 00 FF8016
Type: R/W
Bit 76543210
Name OLFC OHFC WBPSM Reserved IDLE DHF Reserved
Reset 00000000
Bit Description
0Reserved.
1DHF (Disable High-Frequency Oscillator). When cleared (0), the HFCG is enabled. In Active mode, the
HFCG is enabled regardless of the DHF value.
If in Idle mode, DHF can be used to reduce power consumption. When DHF=1, the HFCG is disabled and the
high-frequency clock is not generated. In Power off mode, the HFCG is disabled regardless of the DHF value.
DHF is cleared by the hardware when a hardware wake-up event is detected.
2IDLE. When set, the core domain enters Idle mode on the execution of a WAIT instruction. WBPSM must be
set before executing the WAIT instruction.
This bit can be set and cleared by software; it is cleared by hardware when a hardware wake-up event is detected.
4-3 Reserved.
5WBPSM (Wait Before Entering Power Save Mode). When set, the switch from Active to Idle mode is done by
setting the IDLE bit and executing a WAIT instruction. In addition, if DHF is set, the high-frequency oscillator is
disabled only after the WAIT instruction is executed and Idle mode is entered.
6OHFC (Oscillating High-Frequency Clock).
0: Indicates that the high-frequency clock received by the PMC is either disabled, not available or not producing
a stable clock. When OHFC is cleared, the PMC does not switch to Active mode.
1: Indicates that the high-frequency clock received by the PMC is available and producing a stable clock.
7OLFC (Oscillating Low-Frequency Clock).
0: Indicates that the low-frequency clock received by the PMC is either disabled, not available or not producing a
stable clock. When the OLFC is cleared, the PMC does not switch from Active mode to Power Save or Idle
modes.
1: Indicates that the low-frequency clock received by the PMC is available and producing a stable clock.
Embedded Controller Modules (Continued)
www.national.com 238 Revision1.07
PC87591E/S/L
4.17.5 Usage Hints
The hints below apply when Idle mode is used with a disabled HFCG.
1. When disabling HFCG in Idle mode, on wake-up, a frequency clock may be generated that differs from the selected set-
ting due to temperature variations in the working environment during the idle period. For details on the resulting deviation
from the nominal frequency, refer to “tCLKINTwk” on page 385. To avoid any failures that may result from waking up to
a higher frequency in case the access time to the internal or external memory is marginal using the current BIU config-
uration, follow the procedures exactly.
Before entering Idle mode, configure SZCFGi (where i=0-2) for an additional Wait clock cycle (see Section 4.1.10 on
page 83 for details on SZCFGi configuration).
2. After waking up from Idle mode, wait 0.5 seconds before returning to the optimal SZCFG0 configuration.
Embedded Controller Modules (Continued)
Revision 1.07 239 www.national.com
PC87591E/S/L
4.18 HIGH-FREQUENCY CLOCK GENERATOR (HFCG)
The HFCG generates the high-frequency clock (OSCCLK) based on the system’s 32.768 KHz clock signal. The HFCG out-
put is derived from OSCCLK and generates the host domain clock and the core domain clock. Clock generation is controlled
by the core domain’s PMC module (see Section 4.17 on page 235) and the host domain’s SuperI/O configuration (see
Section 6 on page 335).
To generate OSCCLK, the HFCG includes a programmable frequency multiplier. The core domain clock is derived from
OSCCLK via a programmable pre-scaler; its frequency is in the range of 4 MHz to 20 MHz. The host domain clock is derived
from OSCCLK via a pre-scaler that divides by 2, generating an output of 48 MHz (see Figure 78).
4.18.1 Features
Programmable frequency multiplier for a wide range of output frequencies
Core domain clock and host domain clock generation
Programmable pre-scaler to derive the core domain clock from OSCCLK
Separate enable/disable for core domain clock and host domain clock
On VCC power-up:
4 MHz default core domain clock frequency is set
Host domain clock is disabled
On WATCHDOG reset and Debugger Interface reset:
If host domain clock is enabled, the 48 MHz clock monitor is initiated
If host domain clock is disabled, the 4 MHz default core domain clock frequency is set
4.18.2 Functional Description
Figure 78 shows the HFCG blocks.
The frequency multiplier includes a 5-bit variable (N) and a 14-bit variable (M); these variables define the OSCCLK frequen-
cy. There are two software methods to set the frequency of OSCCLK (by changing N and M); the method used depends on
the HFCG state, as described in Section 4.18.3. The methods are:
Software Method 1. Write new values (HFCGML, HFCGMH and HFCGN registers) to a buffer and enable the programma-
ble frequency setting. Either a normal or fast clock setting may be used. The programmable pre-scaler of the core domain
clock is automatically set to a divide by 1; see “PMC Enabled SuperI/O Disabled State” on page 240.
Frequency
Multiplier
N, M, I
N, M, I
32 KHz
Programmable
Control and Status Host Domain
Clock
Core Domain
Clock
Enable from PMC
Enable from SuperI/O
Pre-Scaler
Parameter Settings
Current Settings
Hardwired Settings
N, M, I for
= Includes software-accessible registers
OSCCLK
Divide by 2
Host Domain
INT to ICU
Figure 78. HFCG Schematic Diagram
= Software
Embedded Controller Modules (Continued)
www.national.com 240 Revision1.07
PC87591E/S/L
Software Method 2. Enable the hardwired frequency setting (M and N are set to generate a 96 MHz OSCCLK). Either a
normal or fast clock setting may be used. The programmable pre-scaler of the core domain clock is set according to the
HFCGP register; see “SuperI/O Enabled State” on page 242.
During a frequency change, the OSCCLK output is low to prevent the system from using an unstable clock.
The HFCG is designed to be tightly coupled with the PMC. The HFCG receives two enable signals: one from the PMC and
the other from the host domain. The PMC can enable or disable core domain clock generation while in Idle mode; it enables
the core domain clock in Active mode. The SuperI/O configuration enables or disables clock generation for the host domain
according to the host processor requests.
4.18.3 HFCG States
There are three groups of HFCG states:
PMC Enabled SuperI/O Disabled: OSCCLK is programmable (set by hardware or by software method 1). The core
domain clock is enabled; the host domain clock is disabled.
SuperI/O Enabled PMC Enabled/Disabled: OSCCLK is fixed at 96 MHz (set by hardware or by software method 2).
The host domain clock is enabled; the core domain clock is either enabled or disabled depending on PMC.
Disabled: OSCCLK is disabled. Both core domain clock and host domain clock are disabled.
Transitions between the states are controlled by either hardware or firmware. Figure 79 illustrates the states and the hard-
ware or software transitions between them. Some of the software settings and transitions are protected to improve the sys-
tem’s durability with regard to software errors; see details in the following sections.
PMC Enabled SuperI/O Disabled State
Normal Clock Setting. This operation enables changing the clock frequency while in PMC Enabled SuperI/O Disabled
state or switching from SuperI/O Enabled PMC Enabled state to PMC Enabled SuperI/O Disabled state.
To change the OSCCLK frequency, load the N and M variables with new values. M is loaded in two parts by writing to
HFCGML and HFCGMH registers.
Load the new setting (N and M values, simultaneously) into the frequency multiplier. The core writes the new variables into
a data input buffer. Then a command loads the new values into the frequency multiplier. The command also loads simulta-
neously the programmable pre-scaler with 0 (set to a divide by 1). Note that HFCGP register does not change its contents.
To set a new clock frequency:
1. Write the N value to HFCGN register.
2. Write the low byte of the M value to HFCGML register.
3. Write the upper bits of the M value to HFCGMH register.
4. Set LOAD in the HFCGCTRL1 register to 1.
SuperI/O Enabled
SuperI/O Enabled
Disabled
PMC Enabled
SuperI/O Disabled
PMC Disabled PMC Enabled
PMC Enabled
PMC Disabled
PMCPMC
SuperI/O
SuperI/O
Disabled
Enabled
Enabled
Disabled
Load or Fast
Load96
Software Transitions
Hardware Transitions
Program Pre-Scaler
Reload M, N, I
or Fast96
May be done in response to
interrupt on SuperI/O Disabled
May be done in response to
interrupt on SuperI/O Enabled
Figure 79. HFCG States and Transitions
Embedded Controller Modules (Continued)
Revision 1.07 241 www.national.com
PC87591E/S/L
When the new HFCGML, HFCGMH and HFCGN register values are loaded, the HFCG holds OSCCLK low until the frequen-
cy multiplier locks onto the target frequency and the new frequency stabilizes. The core domain clock is also low during this
time. This automatic locking process can take several milliseconds to complete.
Frequencies within the range of 4 MHz to 20 MHz are valid. See Table 36 for a sampling of selected frequencies and their
corresponding M and N values.
Table 36. Frequencies of Selected Settings
Fast Clock Setting. This operation enables changing the clock frequency while in PMC Enabled SuperI/O Disabled state
or switching from SuperI/O Enabled PMC Enabled state to PMC Enabled SuperI/O Disabled state.
The HFCG maintains an internal I variable. The I variable is defined by two byte-wide registers: HFCGIL and HFCGIH. If
new M and N values are loaded, the frequency multiplier automatically searches for the I value needed to lock onto the target
frequency. The locking process can take several milliseconds to complete. The I variable can be recorded for a given M and
N set of values and used later to reduce the time needed for frequency locking.
To record the I value:
1. Read the low byte of the I value via HFCGIL register.
2. Check if IVLID bit in HFCGCTRL1 register is set to 0. If yes, repeat steps 1 and 2.
3. Read the upper six bits of the I value via HFCGIH register.
To fast load a new setting, load the M and N values and the corresponding I value. Then set FAST bit in HFCGCTRL1 reg-
ister to 1. The FAST command loads (simultaneously) the new values into the frequency multiplier and loads the program-
mable pre-scaler with 0 (set to a divide by 1). Note that HFCGP register does not change its contents. The frequency
multiplier quickly locks onto the target frequency without searching for a new I value.
To fast set a new clock frequency:
1. Write the N value to HFCGN register.
2. Write the low byte of the M value to HFCGML register.
3. Write the upper bits of the M value to HFCGMH register.
4. Write the low byte of the I value to HFCGIL register.
5. Write the upper six bits of the I value to HFCGIH register.
6. Set FAST bit in HFCGCTRL1 register to 1.
Changes in temperature or voltage may cause variations in the value of I for a given output frequency. If these changes
occur in the interval between recording I and its use, the output frequency generated following a fast frequency setting may
differ from the target frequency. However, after some time, the output frequency converges to the desired frequency.
Frequency1(MHz)
1. This value is referred to as tCLKINTnom in the AC
specifications.
HFCGMH HFCGML HFCGN
4.00 (default) 0316 CF16 0816
5.00 0316 9216 0616
6.00 0316 9216 0516
7.00 0716 8116 0916
8.00 0A16 7C16 0B16
9.00 0A16 B916 0A16
10.00 0A16 B916 0916
12.00 1116 2A16 0C16
14.00 1916 0716 0F16
16.00 1116 2916 0916
18.00 1116 2916 0816
20.00 1716 D616 0A16
Embedded Controller Modules (Continued)
www.national.com 242 Revision1.07
PC87591E/S/L
SuperI/O Enabled State
Normal Clock Setting. This operation enables switching from PMC Enabled SuperI/O Disabled state to SuperI/O Enabled
PMC Enabled state.
To generate a 96 MHz OSCCLK, a command loads the hardwired M and N values (simultaneously) into the frequency mul-
tiplier. At the same time, the command loads the programmable pre-scaler with the value held in HFCGP register. To set a
96 MHz clock frequency and the required core clock.
1. Write the HFCGP value.
2. Set LOAD96 bit in HFCGCTRL1 register.
The HFCGN, HFCGML and HFCGMH registers are ignored and left unchanged when switching to SuperI/O Enabled states.
Fast Clock Setting. This operation enables fast switching from PMC Enabled SuperI/O Disabled state to SuperI/O Enabled
PMC Enabled state.
The HFCG maintains an internal I variable for the 96 MHz clock. The I variable is defined by two byte-wide registers: HFCGIL
and HFCGIH. In a LOAD96 operation, the frequency multiplier automatically searches for the I value needed to lock onto
the target frequency. The locking process can take several milliseconds to complete. The I variable can be recorded for the
96 MHz setting and used later to reduce the time needed for frequency locking.
To record the 96 MHz I value:
1. Write the required HFCGP value.
2. Enter any of the SuperI/O Enabled states using the Normal clock setting or Hardware clock setting process.
To fast set a 96 MHz clock frequency:
1. Write the required HFCGP value.
2. Set FAST96 bit in HFCGCTRL1 register to 1.
The HFCGN, HFCGML and HFCGMH registers are ignored and left unchanged when switching to SuperI/O Enabled states.
4.18.4 The Programmable Pre-Scaler: Core Domain Clock Generation
The core domain clock (CLK) is driven from OSCCLK via a 5-bit pre-scaler. When in PMC Enabled SuperI/O Disabled state,
the pre-scaler divides by 1. In SuperI/O Enabled PMC Disabled state, the pre-scaler is programmable, as defined in HFCGP
register. In other states, the core-domain clock is disabled.
The core domain clock may be set in the range of 4 MHz to 20 MHz.
When LOAD96 or FAST96 bit in HFCGCTRL1 register is set (1), the pre-scaler is set to the value held in HFCGP register
(core frequency = 96 MHz / (HFCGP +1)).
When in SuperI/O Enabled PMC Enabled state, a write to HFCGP register changes the core’s frequency at the next cycle
of the pre-scaler.
When LOAD or FAST bit in HFCGCTRL1 register is set (1), the pre-scaler is automatically set to a divide by 1. The contents
of HFCGP are unchanged.
When in SuperI/O Enabled PMC Enabled state or SuperI/O Enabled PMC Disabled state, WATCHDOG reset or Debugger
Interface reset sets HFCGP to its reset value and initializes the pre-scaler using this value; see Section 4.18.6 on page 243
for details about setting the pre-scaler during state transitions.
When in Disabled state or PMC Enabled and SuperI/O Disabled state, WATCHDOG reset or Debugger Interface reset
keeps the pre-scaler in the divide by 1 operation and loads the HFCGP to its reset value.
In all states, on VCC power-up, WATCHDOG reset or Debugger Interface reset, HFCGP is set to its reset value and the pre-
scaler is set to a divide by 1.
4.18.5 State Transitions
The following section describes the actions taken by the HFCG during state transitions. Unless explicitly specified, the ac-
tions are initiated by hardware.
Transition to PMC Enabled SuperI/O Disabled State
When transitioning from Disabled state:
OSCCLK defaults to a frequency set by the input data buffer (according to the most recent LOAD, FAST or Reset
command).
The pre-scaler defaults to a divide by 1.
When transitioning from SuperI/O Enabled PMC Enabled state:
Software sets OSCCLK and the pre-scaler by the LOAD or FAST command (software method 1).
The host domain clock is disabled (low).
The core domain clock is enabled and starts toggling as soon as the frequency multiplier has stabilized.
Embedded Controller Modules (Continued)
Revision 1.07 243 www.national.com
PC87591E/S/L
When transitioning from SuperI/O Enabled PMC Enabled state, there may be a transition period in which the core domain
clock is still toggling according to the setting in SuperI/O Enabled PMC Enabled state. This occurs until software method 1
is performed by the interrupt handler of the SuperI/O Disabled event.
Transition to SuperI/O Enabled PMC Disabled State
OSCCLK defaults to 96 MHz
The host domain clock is enabled and starts toggling as soon as the frequency multiplier has stabilized
The core domain clock is disabled (low)
Transition to SuperI/O Enabled PMC Enabled State
When transitioning from SuperI/O Enabled PMC Disabled state:
OSCCLK defaults to 96 MHz
The pre-scaler is set according to HFCGP
When transitioning from PMC Enabled SuperI/O Disabled state:
Software sets OSCCLK and the pre-scaler by the LOAD96 or FAST96 command (software method 2)
The host domain clock is enabled and starts toggling as soon as the frequency multiplier has stabilized
The core domain clock is enabled and starts toggling as soon as the frequency multiplier has stabilized
When transitioning from PMC Enabled SuperI/O Disabled state, there may be a transition period in which the core domain
clock is still toggling according to the setting in PMC Enabled SuperI/O Disabled state. This occurs until software method 2
is performed by the interrupt handler of the SuperI/O Enabled event. During this transition period, the host domain clock is
still disabled.
4.18.6 48 MHz Clock Monitor
While in one of the SuperI/O Enabled states, a WATCHDOG reset or Debugger Interface reset does not interfere with the
operation of the SuperI/O. Thus, if the 48 MHz clock is correctly toggling, it is not interfered with. Toggling is monitored by
the 48 MHz clock monitor. If a violation is detected, the 48 MHz monitor error flag is set and the HFCG goes through a com-
plete reset, after which it is put into PMC Enabled SuperI/O Disabled state, ignoring the host domain enable signal.
The 48 MHz clock monitor is initiated when a WATCHDOG reset or Debugger Interface reset occurs while the HFCG is in
a SuperI/O Enabled state. The monitor checks that the host domain clock frequency is in the range of 48 MHz ±1%.
If the host domain clock frequency is in the correct range, the HFCG continues generating the 96 MHz OSCCLK, but the
programmable pre-scaler is set to a default of divide by 24. The HFCG is in SuperI/O Enabled PMC Enabled state.
The core reset routine is responsible for switching to SuperI/O Enabled PMC Enabled state and/or communicating the failure
to the host software.
4.18.7 HFCG Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
HFCG Register Map
Mnemonic Register Name Type
HFCGCTRL1 HFCG Control 1 Varies per bit
HFCGML M Low Byte Value R/W
HFCGMH M High Byte Value R/W
HFCGN N Value R/W
HFCGIL I Low Byte Value R/W
HFCGIH I High Byte Value R/W
HFCGP HFCG Pre-Scaler R/W
HFCGCTRL2 HFCG Control 2 Varies per bit
Embedded Controller Modules (Continued)
www.national.com 244 Revision1.07
PC87591E/S/L
HFCG Control Register 1 (HFCGCTRL1)
The HFCGCTRL1 register sets the frequency multiplier’s operating parameters. On VCC power-up, WATCHDOG reset and
Debugger Interface reset, it is initialized to 0C16.
Location: 00 FFA016
Type: Varies per bit
Bit 76543210
Name Reserved FAST96 LOAD96 IVLID OHFC PENABLE FAST LOAD
Reset 00001100
Bit Type Description
0WOLOAD (Load M and N Values). Write 1 to this bit to perform a normal frequency change by loading
the HFCGML, HFCGMH and HFCGN buffer data to the frequency multiplier. The pre-scaler is
automatically set to a divide by 1. The bit always reads back 0. Results are undefined when more than
one of the following bits is written with 1 at the same time: LOAD, FAST, LOAD96, FAST96.
1WOFAST (Load M, N and I Values). Write 1 to this bit to perform a fast frequency change by loading the
HFCGML, HFCGMH, HFCGN, HFCGIH and HFCGIL input buffer data in the frequency multiplier. The
pre-scaler is automatically set to a divide by 1. The bit always reads back 0. Results are undefined when
more than one of the following bits is written with 1 at the same time: LOAD, FAST, LOAD96, FAST96.
2ROPMC ENABLE (Enable Core Domain Clock). Provides the status of the PMC enable/disable
command. Any data written to this bit is ignored.
0: Disabled
1: Enabled
3ROOHFC (Output Clock Status). Indicates when the HFCG is oscillating and produces a stable clock.
Any data written to this bit is ignored.
0: Not oscillating
1: Oscillating with stable output
4ROIVLID (I Value Valid).
0: Data read is invalid; repeat HFCGIL register read operation
1: Data read is valid; HFCGIH can be read
5WOLOAD96 (Load M and N Values for 96 MHz). Write 1 to this bit to perform normal locking on 96 MHz
frequency by loading the hardwired variables M and N to the frequency multiplier. The pre-scaler is set
according to the value held in HFCGP register. The bit always reads back 0. Results are undefined
when more than one of the following bits is written with 1 at the same time: LOAD, FAST, LOAD96,
FAST96.
6WOFAST96 (Load M, N and I Values for 96 MHz). Write 1 to this bit to perform fast locking on 96 MHz
frequency by loading the hardwired variables M and N and registers HFCGIH and HFCGIL to the
frequency multiplier. The pre-scaler is set according to the value held in HFCGP register. The bit
always reads back 0. Results are undefined results when more than one of the following bits is written
with 1 at the same time: LOAD, FAST, LOAD96, FAST96.
7Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 245 www.national.com
PC87591E/S/L
HFCGM Low Value Register (HFCGML)
The HFCGML register contains the lower eight bits of the frequency multiplier M value. Data written to the register is stored
in the setup buffer. Reading the register returns the HFCGML value of the currently set frequency. On VCC power-up,
WATCHDOG reset and Debugger Interface reset, it is loaded with CF16.
Location: 00 FFA216
Type: R/W
HFCGM High Value Register (HFCGMH)
The HFCGMH register contains the upper bits of the frequency multiplier M value. Data written to the register is stored in
the setup buffer. Reading the register returns the HFCGMH value of the currently set frequency. On VCC power-up, WATCH-
DOG reset and Debugger Interface reset, it is loaded with 0316.
Location: 00 FFA416
Type: R/W
HFCGN Value Register (HFCGN)
The HFCGN register is a byte-wide, read/write register containing five bits of the frequency multiplier N value. Data written to the
register is stored in the setup buffer. Reading the register returns the HFCGN value of the currently set frequency. On VCC
power-up, WATCHDOG reset and Debugger Interface reset, it is loaded with 0816.
Location: 00 FFA616
Type: R/W
Bit 76543210
Name HFCGM7-0
Reset 11001111
Bit Description
7-0 HFCGM7-0. Contains the lower eight bits of the M value.
Bit 76543210
Name HFCGM
Reset 00000011
Bit Description
7-0 HFCGM. Contains the upper bits of the M value.
Bit 76543210
Name Reserved HFCGN4-0
Reset 00001000
Bit Description
4-0 HFCGN4-0. Contains the five bits of the N value.
7-5 Reserved.
Embedded Controller Modules (Continued)
www.national.com 246 Revision1.07
PC87591E/S/L
HFCGI Low Value Register (HFCGIL)
The HFCGIL register contains the lower eight bits of the frequency multiplier I value. Data written to the register is stored in
the setup buffer. Reading the register returns the value of its first 8 bits. (IVLID bit in HFCGCTRL1 register indicates if the
data is valid.)
Location: 00 FFA816
Type: R/W
HFCGI High Value Register (HFCGIH)
The HFCGIH register is a byte-wide, read/write register containing the upper six bits of the frequency multiplier I value. Data
written to the register is stored in the setup buffer. Reading the register returns the HFCGIH value of the currently set fre-
quency.
Location: 00 FFAA16
Type: R/W
HFCG Pre-Scaler Register (HFCGP)
The HFCGP register is a byte-wide, read/write register. It allows the core clock to be derived from the 96 MHz clock.
On reset HFCGP is initialized to 1716.
Location: 00 FFAC16
Type: R/W
Bit 76543210
Name HFCGI7-0
Bit Description
7-0 HFCGI7-0. Contains the lower eight bits of the I value.
Bit 76543210
Name Reserved HFCGI13-8
Bit Description
5-0 HFCGI13-8. Contains the upper six bits of the I value.
7-6 Reserved.
Bit 76543210
Name Reserved HFCGP4-0
Reset 00010111
Bit Description
4-0 HFCGP4-0 (Pre-Scaler Divider Value). The divider of OSCCLK is the number defined by HFCGP(4-0) + 1,
e.g., a value of 0016 results in a divide by 1; a value of 1F16 results in a divide by 32.
Results are undefined when the pre-scaler holds a value that yields a core domain clock frequency higher than
20 MHz or lower than 3 MHz.
The pre-scaler is set according to the value held in HFCGP register when LOAD96 bit or FAST96 bit is set (1).
Reading HFCGP register returns the last value written to it.
7-5 Reserved.
Embedded Controller Modules (Continued)
Revision 1.07 247 www.national.com
PC87591E/S/L
HFCG Control Register 2 (HFCGCTRL2)
The HFCGCTRL2 register sets the frequency multiplier’s operating parameters. On VCC power-up, WATCHDOG reset and
Debugger Interface reset, it is initialized to 0016.
Location: 00 FFAE16
Type: Varies per bit
Bit 76543210
Name Reserved 96MON MONERR SCESTP SCESTR SENABLE
Reset 00000000
Bit Type Description
0ROSIO ENABLE (Enable Host Domain Clock). Provides the status of the SuperI/O enable/disable
command. Any data written to this bit is ignored.
0: Disabled
1: Enabled
1 R/W1C SCESTR (SIO Clock Enable Start). Indicates that a rising edge was detected on the SENABEL
signal. When set, an interrupt is sent to the ICU (level high). Cleared by writing 1 to it. This interrupt
may be masked only in the ICU.
0: No rising edge on SENABLE was detected (default)
1: A rising edge on SENABLE was detected and an interrupt is sent to the ICU
2 R/W1C SCESTP (SIO Clock Enable Stop). Indicates that a falling edge was detected on the SENABEL
signal. When set, an interrupt is sent to the ICU (level high). Cleared by writing 1 to it. This interrupt
may be masked only in the ICU.
0: No falling edge on SENABLE was detected (default)
1: A falling edge on SENABLE was detected and an interrupt is sent to the ICU
3 R/W1C MONERR (Monitor Error). Indicates that a 48 MHz monitor error was detected during the last
WATCHDOG or Debugger Reset process. Note that this bit is cleared by all resets except WATCHDOG
and Debugger Interface resets. Once set, this bit is cleared by writing 1 to it.
0: No error detected (default)
1: 48 MHz monitor detected an out of range frequency
4RO96MON (96 MHz Oscillations On). Indicates the oscillation frequency at which the HFCG is operating.
0: HFCG is oscillating as defined by the HFCGM and HFCGN. The core clock is identical to HFCG fre-
quency.
1: HFCG is oscillating at 96 MHz. The core clock is pre-scaled as defined by HFCGP.
7-5 Reserved.
Embedded Controller Modules (Continued)
www.national.com 248 Revision1.07
PC87591E/S/L
4.19 THE DEBUGGER INTERFACE
The Debugger Interface module links between a debugger running on a host machine and the PC87591x.
The Debugger interface associates a processor number with the processor core. The number associated with the core is 0.
The Debugger interface can also program the on-chip flash.
4.19.1 Features
Debugger communication via an IEEE 1149.1b 1994 JTAG serial bus
Test Access Port (TAP) for JTAG serial bus
Hardware reset signal assertion by debugger command
Configurable ABORT event
Interrupt signal (TINT) to the debugger indicates a waiting message
Waiting message to on-chip processor by non-maskable ISE interrupt
8-word (16-byte) Rx (downstream) data link
8-word (16-byte) Tx (upstream) data link
On-chip flash support
Read, Program and Erase
Read protect option to secure contents
4.19.2 Structure
The Debugger interface consists of a TAP, ISE Interrupt Control, Rx and Tx data links and a PC87591x reset-by-command
source circuit. Figure 80 shows these functional blocks.
Figure 80. Debugger Interface
Rx Data
Peripheral Bus
Tx Data
ISE Interrupt
Control
TAP
JTAG Serial Bus TINT
ISE
Interrupts
Debugger
Reset
Link Link
Flash Programing
Interface
To
Flash
On-Chip To
Reset Circuit
and Flash
Embedded Controller Modules (Continued)
Revision 1.07 249 www.national.com
PC87591E/S/L
The TAP block has an IEEE 1149.1b 1994 standard interface to a JTAG serial bus. In addition, it uses TINT to notify the
host/debugger that a message is waiting upstream. The TAP and the JTAG form the debugging communication channel and
port for the PC87591x. They operate as follows:
The TAP copies downstream messages (from the debugger to one of the on-chip processors) to the Rx data link, to
be read by the relevant processor via the peripheral bus.
A processor writes upstream messages (from an on-chip processor to its debugger) to the Tx data link for upstream
transmission via the JTAG serial bus.
The ISE interrupt control generates ISE interrupts to the processor in cases of ABORT or a waiting message in the
Rx data link.
The debugger reset circuit generates a PC87591x reset by a debugger command. This is in addition to the Power-Up
and Hardware reset sources.
Flash access (control, status, read, write and erase) interface and control is provided. The Debugger interface gen-
erates a reset signal when JTAG access to the flash is enabled.
4.19.3 Debugger Interface Functional Description
The Debugger interface supports four operating modes: Rx session, Tx session, chip RESET and ABORT. Some of these
modes can be active simultaneously for the same or different processors. The ISE interrupt control block includes hooks to
control these conditions.
Rx Session (Sending Data Downstream)
A message sent downstream by the debugger to a processor is called an Rx session. In an Rx session, a debugger uses
both the TAP and the JTAG to monitor the “busy” indication for the Rx data link. Following a “not busy” indication, a message
is sent to a processor via the JTAG, TAP and Rx data link.
One of the internal ISE interrupts is asserted (if not active) according to the PID field of the instruction currently loaded into
the TAP IR register. The signaled processor accesses the data link via the peripheral bus, reads the message length (op-
tional) and fetches it from the Rx data buffer.
At the end of the data transfer, the processor turns off the “busy” indication of the Rx data link.
Tx Session (Sending Data Upstream)
A message sent upstream by a processor to the debugger is called a Tx session. In a Tx session, one of the processors
tries to own the Tx data link by accessing the Tx semaphore DBGTXLOC register. If successful, it writes a message body
to the Tx data buffer and a message length, in words, to DBGTXST register.
After completion of the data buffer update, the processor sets ASSERT bit in DBGTINT register to 1. This signals the de-
bugger with an active-low pulse on TINT. The debugger reads the data using both the TAP and the JTAG.
At the end of the data transfer, the semaphore circuit is set to “not busy” and TINT is released.
Chip RESET
The PC87591x is reset by a dedicated TAP instruction.
ABORT
Either a TAP instruction or a bit-set operation in DBGABORT register generates an ABORT. Asserting an ISE interrupt to-
gether with a non-zero ABORT_i bit in DBGISESRC register signals an ABORT operation. The ISE interrupt control circuit
asserts the ISE interrupt according to the pre-programed mask bits in ABORT_MASK register. A dedicated circuit, together
with a set of registers in the ISE Interrupt Control, clears the ISE requests after they have been served.
Rx Data Link
The Rx data link consists of an 8-word read/write data buffer, DBGRXD0 to DBGRXD7 registers and the Status (DBGRXST)
register.
On PC87591x reset, DBGRXST register is set to its reset value. On TAP reset, the data link maintains its values.
When the TAP controller is in Update-DR state and the current IR is SCAN_RX, DBGRXDX registers are updated from the
TAP Data Shift (DBGDATA) register. Data is valid to the processor only while BUSY bit in DBGRXST register is set. In this
case (i.e., Update-DR of SCAN_RX), the TAP controller copies the PID and length fields from its IR to the Status register
and sets BUSY bit to 1 in this state.
A processor may turn off the BUSY bit by writing 1 to it. BUSY can be cleared even when TCK is not toggling. The Rx data
link functions in Active or Idle modes.
DBGDATA length is set to the length field of the SCAN_RX instruction before Capture_DR state (see Section 4.19.7 on
page 260). No parallel load is executed in Capture-DR state.
Embedded Controller Modules (Continued)
www.national.com 250 Revision1.07
PC87591E/S/L
TX Data Link
The Tx Data link consists of an 8-word, read/write data buffer, DBGTXD0 to DBGTXD7 registers, a read/write Status register
(DBGTXST), a read/write semaphore lock register (DBGTXLOC) and a write-only TINT control register (DBGTINT).
On Power-Up reset, the Tx Data link is reset (negating any pending message), DBGTXLOC and DBGTXST are set to their
reset values and TINT is released (1). On Warm and Internal reset, any partial message (i.e., TINT=1) is negated by setting
DBGTXLOC and DBGTXST to their reset values. Messages that were completed (i.e., TINT=0) are maintained for transmis-
sion to the host by maintaining DBGTXLOC and DBGTXST values.
On TAP reset, the data link maintain its values.
DBGTXD registers are captured by the TAP data shift register (DBGDATA) in Capture-DR state of the TAP controller when
the current Information Register (IR) is SCAN_TX. The DBGDATA length is set dynamically, according to the length field of
DBGTXST register before the Capture_DR state of the SCAN_TX operation (see Section 4.19.7 on page 260). The TAP IR
register captures the values of PID and MSG_LEN fields of DBGTXST register when the TAP controller is in Capture-IR
state. No parallel load is executed in Update-DR state.
The semaphore is implemented by DBGTXLOC register. A write operation, to PID field of this register, of a value other than
‘1111’ changes the contents of this field only when the PID field equals ‘1111’. This field returns to ‘1111’ in one of the fol-
lowing ways:
Write operation of ‘1111’ to PID field of DBGTXLOC register from the peripheral bus while TINT is not asserted
Update-DR state of the TAP controller when the current instruction loaded into TAP IR register is SCAN_TX (this ac-
tion take place at the rising edge of TCK)
On Warm or Internal reset if TINT=1 and on Power-Up reset
A processor can access DBGTXDi registers in Active mode only. For a processor to gain ownership of the Tx link, it must
capture the DBGTXLOC semaphore using the following sequence:
1. Verify that the value of PID in DBGTXLOC register is ‘1111’.
2. Write the processor PID code to DBGTXLOC register.
3. Read DBGTXLOC. If the PID field is equal to the value that was written, the data link is granted. If not, repeat step 1.
A processor should access DBGTXDi and DBGTXST registers only after successfully gaining ownership over the Tx link by
using the above sequence.
The TINT signal is an active-low pulse asserted by the Tx data link when ASSERT bit in DBGTINT register is written with 1.
It is de-asserted, together with the semaphore indication in Update-DR state of the TAP controller, when the current instruc-
tion loaded into TAP IR register is SCAN_TX.
Access to DBGTXLOC, DBGTXST and DBGTXDi registers should be done only while TINT is not asserted. TINT negation
can be identified by the release of PID (‘1111’).
Debugger Reset Circuit
Chip reset is asserted in the Update-DR state of the TAP controller when the current instruction is ASSERT_DBG_RST. This
triggers a Debugger reset, as described in “ASSERT_DBG_RST” on page 260. This circuit is functional in Active or Idle
modes. It is functional, while TCK is not toggling, one cycle after exit from Update-DR state.
ISE Interrupt Control
The ISE interrupt control module sends ISE interrupt requests to the processor core. It consists of the write-only DBGABORT
register, the read/write DBGISESRC register, and the DBGMASKS shift register.
The DBGISESRC register is cleared on PC87591x reset. During TAP reset, the values of these registers are maintained.
The DBGMASKS value is modified only in Update-DR state of the TAP controller when the current instruction is
SCAN_ABORT_MASK.
The ISE interrupt control module issues an ISE interrupt request to a specific processor or multiple processors, together with
the matched bit in DBGISESRC register, according to the MESSAGE or ABORT event.
In a MESSAGE event, an ISE interrupt is requested for a specific processor according to the PID field of the SCAN_RX
instruction. The request is issued (together with DBGISESRC bit assertion) if the current instruction loaded in TAP IR is
SCAN_RX and the TAP controller is in Update-DR state (rising edge of TCK).
An ABORT event occurs when SCAN_RX is executed with a PID of all 1s (ISE and ABORT_i bits in DBGISESRC register
are asserted) or when processor bits P_i are set in DBGABORT register by one of the processors. That is, ISE and
DBGISESRC bits are asserted with the write operation itself; if DBGABORT is written with some 0 bits, the PIDs related to
these bits do not get the ISE. In an ABORT event, the assertion of each ISE interrupt and DBGISESRC bit depends on its
masking bit in DBGMASKS register.
Embedded Controller Modules (Continued)
Revision 1.07 251 www.national.com
PC87591E/S/L
Each ISE interrupt is cleared when ABORT_i and RX_i in DBGISESRC register are both 0. Any bit in DBGISESRC register
is cleared by writing 1 to it (writing 0 is ignored). If there is a new source activity in the same write cycle during which
DBGISESRC register of a specific processor is cleared, the ISE interrupt control asserts ISE again, together with its source
bit.
The ISE interrupt is an active-high pulse. For nested ISE sources, the ISE remains asserted, and the ISE interrupt control
module sets the new source bit to 1.
The DBGMASKS register is not available to the peripheral bus; it is accessed only from the JTAG serial bus when the
SCAN_ABORT_MASK instruction is loaded into the TAP IR.
The ISE signal, together with its source bit, should be asserted in Active or Idle modes for wake-up purposes when the
source is a debugger message or debugger abort. Other functionality should be consistent while changing modes (i.e., dur-
ing wake-up). Full functionality of this module is maintained even when TCK is not toggling.
Clock Synchronization
Some operations are related to TCK, others to the PC87591x main clock and yet others are asynchronous. The PC87591x
logic guarantees correct operation and a meta-stable protected interface in all its operating modes (i.e., Active and Idle).
The core may access the Debugger interface registers only in Active mode.
4.19.4 Flash Interface Functional Description
The Flash interface enables access to the flash through the JTAG serial bus without any core involvement. This enables a
firmware-independent update of flash contents.
The Flash interface is divided into three parts:
Flash Control and Status: Controls flash operations and returns flash status.
Flash Address: Stores the address for flash operations and includes an auto-increment mechanism for speeding up
the flash update process.
Flash Data: Handles flash data for both read and write operations.
Enabling Access to the Flash
The flash can be accessed through the JTAG serial bus in OBD and DEV environments. In IRE and PROG environments,
access cannot be enabled (i.e., write operations to the JTAG Access Enable (JTFIE) bit in the Flash Control and Status reg-
ister, FL_CT_ST, are ignored).
To enable Flash interface access to the flash, use the following sequence:
1. Set Instruction Register (IR) to Flash Control Scan Instruction.
2. Scan in a code with the Flash JTFIE bit in FL_CT_ST register is set to enable access to the PC87591x.
3. Repeat step 2 until the FMBUSY bit in FL_CT_ST register is cleared.
Enabling the flash puts the PC87591x in Reset state. It remains in this state, with the clocks enabled and any core or host
activity disabled, until the Flash interface is again disabled. To disable the flash, clear the JTFIE bit. This releases the
PC87591x from reset and enables the core to start executing the code stored in the flash.
Flash Contents Protection
The flash has a contents protection mechanism that protects the flash contents from read operations and prevents them
from being altered during write transactions. When this mechanism is set, only a special erase that erases the entire flash
can be performed.
When the Blank Flash flag is set, it indicates to the core that the flash has no valid code and that the core should remain in
Reset state until the protection information is changed. Both this flag and the Access Enable flag are part of the flash pro-
tection byte and should be programed after the flash is loaded with data. See Section 4.16.6 on page 226.
Flash Data Read
To read the contents of the flash, perform the following sequence:
1. Enable flash access (if not already enabled).
2. Set the flash to read as follows:
a. Set the IR to Flash Control and Status Scan instruction.
b. Scan in a read operation code (800016).
3. Set the address as follows:
a. Set IR to Flash Address Scan instruction.
b. Scan the address of the memory location to be read into the chip.
Embedded Controller Modules (Continued)
www.national.com 252 Revision1.07
PC87591E/S/L
4. Read the data as follows:
a. Set IR to Flash Data Read Scan instruction.
b. Scan out of the chip the first word of the data.
c. Repeat step b for additional data words for consecutive addresses.
Flash Data Erase
Pages, sections or the entire flash device (special erase) can be erased. If the flash is locked (FLAEN in the Flash Status
register is set), a special erase must be performed.
To select and perform a flash erase, perform the following sequence:
1. Enable flash access (if not already enabled).
2. Set the desired erase mode as follows:
a. Set IR to Flash Control and Status Scan instruction.
b. Scan in a code of 810016 (page erase), 820016 (section erase) or 840016 (special erase).
3. Set the address as follows:
a. Set IR to Flash Address Scan instruction.
b. Scan an address into the memory block to be erased, specifying the correct block.
4. Erase the page or section as follows:
a. Set IR to Flash Data Erase Scan instruction.
b. Scan the erase command into the chip with 116 data.
c. Repeat the scan with 016 data until the Busy status flag indicates erase completion. The Error bit indicates if the erase
was successful. In case of an error, the failing address is provided in Flash Address register.
d. To erase additional pages or sections, repeat the Set Address (3) and Erase (4) operations.
5. Erase the entire flash device (special erase) as follows:
a. Set IR to Flash Data Erase Scan instruction.
b. Scan the erase command into the chip with 116 data.
c. Repeat the scan with 016 data until the Busy status flag indicates erase completion. The Error bit indicates if the erase
was successful. In case of an error, the failing address is provided in Flash Address register.
d. If there is no error indication, repeat steps b and c two more times.
Flash Data Write
Writing data to the flash should be done after properly erasing the page (see “Flash Page Organization and Erase Options”
on page 221 for flash write after erase limitations).
To write data, perform the following sequence:
1. Enable flash access (if not already enabled).
2. Set the flash to Program mode as follows:
a. Set IR to Flash Control and Status Scan instruction.
b. Scan in a code of 808016 for program enable.
3. Set the address as follows:
a. Set IR to Flash Address Scan instruction.
b. Scan an address into the memory address to be written.
4. Write the block as follows:
a. Set IR to Flash Data Write Scan instruction.
b. Scan the write data into the chip with the data byte/word and Valid bit set.
c. Repeat the scan instruction as long as the Valid bit is cleared, checking for the returned Valid status flag to indicate
a ‘not busy’ status. The Error bit indicates if an error occurred during the write process of the previous word. On suc-
cessful write completion, the address is incremented to the next address. In case of an error, the failing address is
provided in Flash Address register; further writes are disabled until the error flag is cleared. The exact source of the
error is provided in FL_CT_ST register. The error may be cleared using FL_CT_ST register.
5. Repeat the write operation (step 4) for writing data to successive addresses.
6. Check that the write is completed by reading the Flash Status bit until it indicates that the flash is not busy; to do this:
a. Set IR to Flash Control and Status Scan instruction.
b. Scan in a code of 808016, maintaining the program enable.
c. Check the capture status for completion of the last write (the FMBUSY bit should be cleared).
d. Repeat steps b and c until the flash is not busy.
Embedded Controller Modules (Continued)
Revision 1.07 253 www.national.com
PC87591E/S/L
Flash ID Read
To identify the device version, perform the following sequence:
1. Enable flash access (if not already enabled).
2. Read the Device ID (SID and SRID register values), using the Device ID Scan, as follows:
a. Set the IR to Device ID Scan instruction.
b. Scan the LF_ID chain.
4.19.5 Test Access Port (TAP)
This section defines the top-level design of the TAP, as illustrated in Figure 81. Subsequent sections provide detailed TAP
design requirements.
The TAP includes the following elements:
TAP signals
TAP controller
Instruction Register (IR)
Data registers (Debugger and Flash interfaces).
The Instruction and data registers have separate shift register-based paths connected in parallel. These registers have a
common serial data input and a common serial data output connected to the TAP TDI and TDO signals, respectively.
The TAP controller selects between TDI and TDO as the alternative instruction and data register paths.
Figure 81. TAP Block Diagram
DBGDATA Register
Instruction Register
Instruction Decode
Output Buffer
TDI TDO
Clocks and/or Controls
TAP Controller
TMS
TCK
DBGMASKS Register
BYPASS Register G
FL_ADDR Register
FL_DATA Register
FL_ID Register
FL_CT_ST Register
FL_ERASE Register
Embedded Controller Modules (Continued)
www.national.com 254 Revision1.07
PC87591E/S/L
Further Information
The TAP is based on the test logic in the IEEE 1149.1b-1994 specification. However, since its purpose is to facilitate com-
munication, it does not support IEEE 1149.1b-1194 testing facilities. It is used here to benefit from off-the-shelf bus controller
cards and software and potential future enhancements to the test scheme.
This document includes the relevant rules of this specification. See the following documents for further information.
For further details and examples of the standard, see IEEE Standard Test Access Port and Boundary-Scan Architec-
ture, May 21, 1990.
For further details of test bus chips and equipment, see the relevant manufacturer datasheets and application notes,
e.g., SCANTM Data book, National Semiconductor 400102.
For technical background, refer to text books on the subject, for example, Colin M. Maunder and Rodham E. Tulloss,
“The Test Access Port and Boundary-Scan Architecture”, IEEE Computer Society Press Tutorial.
TAP Signals
The TAP interface signals to the JTAG serial bus are: Test Clock Input (TCK), Test Mode Select Input (TMS), Test Data Input
(TDI) and Test Data Output (TDO). The TAP controller is reset at Power-Up reset only; see Section 3.2 on page 65 for further
information.
TCK. TCK provides the clock for the JTAG serial bus and the TAP controller. Stored-state devices in the TAP maintain their
state indefinitely after the signal applied to TCK is stopped.
TMS. The TAP controller next state is set by the TMS value and its current state. The TAP samples the signal presented at
TMS on the rising edge of TCK.
Circuitry, fed from TMS, produces the same response to the application of a logic 1 as for a non-driven input.
TDI. This is the data and instructions serial input. The TAP samples the signal presented at TDI on the rising edge of TCK.
Circuitry fed from TDI produces the same response to the application of a logic 1 as for a non-driven input.
When data is shifted from TDI towards TDO, test data received at TDI appears without inversion at TDO following a number
of rising and falling edges of TCK. This is determined by the length of the instruction or Test Data register selected.
TDO. This is the data and instructions serial output. The signal driven through TDO changes its state only after the falling
edge of TCK.
The TDO driver is set to its inactive drive state, except while data or an instruction is being scanned.
TAP Controller
The TAP controller is a synchronous, finite state machine that responds to changes in the TMS and TCK signals and controls
the sequence of operations of the PC87591x reset, ISE interrupt control and data link circuitry.
Figure 82 shows the TAP controller state diagram.
Embedded Controller Modules (Continued)
Revision 1.07 255 www.national.com
PC87591E/S/L
Figure 82. TAP Controller State Diagram
For a detailed description of the controller states, see the IEEE 1149.1b-1994 specifications.
All state transitions of the TAP controller occur based on the value of TMS on the rising edge of TCK. TAP actions (described
in Sections 2.1.3 to 2.1.7) occur either on the rising or falling edge of TCK in each controller state, as shown in Figure 83.
Figure 83. Timing of Actions in a Controller State
Tap-Reset
Run-Test
Idle Select-
DR-Scan
Capture-DR
Shift-DR
Exit1-DR
Pause-DR
Exit2-DR
Update-DR
0
0
1
0
1
1
1
0
1
0
0
1
0
01Select-
IR-Scan
Capture-IR
Shift-IR
Exit1-IR
Pause-IR
Exit2-IR
Update-IR
0
0
1
0
1
1
1
0
1
0
0
1
0101
Note: The value for each state transition represents the signal on TMS
1
for a rising edge at TCK.
State Entered
Controller State
TCK
Actions Occurring on the
Falling Edge of TCK
Actions Occurring on
Rising Edge of TCK
Embedded Controller Modules (Continued)
www.national.com 256 Revision1.07
PC87591E/S/L
TAP Controller Operation
The TAP controller changes state only in response to the following events:
A rising edge of TCK
Power-up
The TAP controller generates signals to control the operation of the TAP registers and associated PC87591x reset, ISE in-
terrupt control and data link circuitry.
The TDO output buffer and the circuitry that selects the register output fed to TDO are controlled as shown in Table 37.
Changes at TDO, as defined in Table 37, occur on the falling edge of TCK after entry into the state.
Table 37. TAP Operation in Each Controller State
TAP Controller Initialization
Circuitry built into the PC87591x forces the TAP controller into TAP-Reset state at power-up in an asynchronous manner.
The TAP controller must not be initialized by operation of any system input, such as a system reset.
When TMS is equal to 1 for five consecutive TCK cycles, this forces the controller into TAP-Reset state from any state.
4.19.6 TAP Instruction Register
The Instruction Register (IR) allows an instruction to be shifted into the Debugger interface. The instruction selects the mode
of operation, the data register to be addressed or both.
In any serial scan operation, the JTAG serial bus controller transmits and receive vectors of the same length. This serial
scan chain property is used to transmit status bits from the device to the bus controller in any instruction scan operation. The
Instruction register in the PC87591x allows status information generated within the data links to be examined and supports
flash programing, as shown in Table 38 on page 257.
Design and Construction
The IR uses a shift register-based design with a parallel input for register cells other than the two nearest to the serial output.
An instruction, shifted into the register, is latched at the completion of the shifting process.
The IR includes 12 shift register-based cells capable of holding instruction data.
An instruction that is shifted into the register is latched so that the related changes occur only in the Update IR and TAP-
Reset states.
Controller State Register Selected to Drive TDO TDO Driver Level
Tap-Reset Undefined Inactive
Run-Test-Idle Undefined Inactive
Select-DR-Scan Undefined Inactive
Select-IR-Scan Undefined Inactive
Capture-IR Undefined Inactive
Shift-IR Instruction Active
Exit1-IR Undefined Inactive
Pause-IR Undefined Inactive
Exit2-IR Undefined Inactive
Update-IR Undefined Inactive
Capture-DR Undefined Inactive
Shift-DR Test Data Active
Exit-DR Undefined Inactive
Pause-DR Undefined Inactive
Exit2-DR Undefined Inactive
Update-DR Undefined Inactive
Embedded Controller Modules (Continued)
Revision 1.07 257 www.national.com
PC87591E/S/L
Data is not inverted between the serial input and serial output of IR.
The IR parallel input status bits, loaded at the Capture IR state of any instruction scan operation, are shown below.
Instruction Register Operation
Table 38 shows the behavior of IR in each TAP controller state.
All actions resulting from an instruction terminate when a new instruction is transferred to the parallel output of the IR (i.e.,
in Update-IR or TAP-Reset states).
All operations of the shift register stages occur on the rising edge of TCK after entry into a TAP controller state.
Table 38. Instruction Register Operation in Each Controller State
The data present at the parallel output of the IR is latched from the shift register stage on the falling edge of TCK in Update-
IR state.
After entry into TAP-Reset state as a result of TAP controller clocked operation, the BYPASS instruction is latched onto the
IR output on the falling edge of TCK.
Bit 1176553210
Name MSG_LEN PID RX_BUSY 0 1
Reset
Bit Description
0 Fixed value (1).
1 Fixed value (0).
2RX_BUSY (Receive Busy). Busy indication from the Rx data link.
6-3 PID (Processor ID). Contains the processor ID from the Tx data link.
When TINT is set to 1 (not active), PID field is ‘1111’, indicating that the Tx link has no valid data.
When TINT is set to 0 (active), PID field indicates the value of PID field in DBGTXLOC register. Note that this
value is latched when TINT becomes active and is held until the Rx data is read by the host.
11-7 MSG_LEN (Message Length). Contains the Tx message length in words. When the Tx status word PID field is
not ‘1111’, the MSG_LEN holds a copy of the MSG_LEN field in DBGTXST register. When the size of this field
is less than five bits, the MSG_LEN MSBs in the status word are forced to 0.
Controller State Shift Register Stage Parallel Output
TAP-Reset Undefined Set to give BYPASS instruction
Capture-IR Load status data (table 2-2) Retain last state
Shift-IR Shift towards serial output Retain last state
Exit1-IR
Exit2-IR
Pause-IR
Retain last state Retain last state
Update-IR Retain last state Load from shift register stage
All other states Undefined Retain last state
Embedded Controller Modules (Continued)
www.national.com 258 Revision1.07
PC87591E/S/L
Instructions
Instructions are entered serially into the Debugger interface logic during an IR scan by using the IR. See Table 39 for the
required binary codes.
Table 39. IR Instruction Binary Codes
Note:
1. D0 is the nearest to the serial output.
2. “X” means ignore.
3. Debugger abort is generated by SCAN_RX when PID=‘1111’.
Data registers not selected by the current instruction do not interfere with the operation of the on-chip system logic or with
the selected data registers.
Each instruction enables a single serial data register path to shift data between TDI and TDO in Shift-DR state, as shown in
Table 40.
Instruction codes that are not required to control test logic are equivalent to the BYPASS instruction.
BYPASS
The BYPASS instruction operates the BYPASS register. This register contains a single shift register stage and provides a min-
imum-length serial path between the TDI and TDO pins of a component when no test operation is needed for that component.
This allows more rapid movement of test data to and from other board components that are required to perform test operations.
The BYPASS instruction selects BYPASS register to be connected for serial access between TDI and TDO in the Shift_DR state.
If the BYPASS instruction is selected, all other data registers continue their normal functionality.
Flash Support Instructions
Flash Control Scan
The Flash Control Scan instruction switches the data scan path to FL_CT_ST register. During this instruction, the length of
the scan chain is 16 bits. In this case, the Control and Status register of the flash can be scanned. In the Capture-DR state
of the TAP controller, the Status register is latched into the FL_CT_ST register chain. During the Update-DR state, the Con-
trol register is loaded with the contents of FL_CT_ST register. Some bits are shared between the two registers and operate
as read/write or read/write 1 to clear.
Device I/D Scan
The Device I/D Scan instruction switches the data scan path to FL_ID register. During this instruction, the length of the scan
chain is 32 bits. In this case, SID and REVID registers of the SuperI/O are read and their contents are sampled in the
Capture-DR state. No updates are made during the Update-DR state.
Flash Address Scan
The Flash Address Scan instruction switches the data scan path to FL_ADDR register. During this instruction, the length of
the scan chain is 32 bits. In this case, the Address register of the flash can be scanned. In the Capture-DR state of the TAP
controller, the flash address is latched into the FL_ADDR chain. During the Update-DR state, if the Block ID field is other
than ‘0000’, Flash Address register is loaded with a new value from FL_ADDA and the Valid bit in the data register is cleared.
After Flash Address register is loaded, a read operation from the array is performed, the result is stored in the Flash Read
Data buffer, and the Data Read buffer Valid bit is set.
D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Instruction
x x x x x x x x x 1 1 1 BYPASS
x x x x x x x x x 0 0 0 BYPASS (Reserved for Scan)
x x x x x x x x x 1 1 0 BYPASS
0 0 0 0 0 0 0 0 0 0 0 1 Flash Control Scan
0 0 0 0 0 0 0 0 1 0 0 1 Device I/D Scan
0 0 0 0 0 0 0 1 0 0 0 1 Flash Address Scan
0 0 0 0 0 0 1 1 0 0 0 1 Flash Data Read Scan
0 0 0 0 0 1 0 1 0 0 0 1 Flash Data Write Scan
0 0 0 0 0 1 1 1 0 0 0 1 Flash Erase Scan
other 0 0 1 BYPASS
L4 L3 L2 L1 L0 PID3 PID2 PID1 PID0 0 1 0 SCAN_RX
x x x x x x x x x 0 1 1 SCAN_TX
x x x x x x x x x 1 0 1 SCAN_ABORT_MASK
x x x x x x x x x 1 0 0 ASSERT_DBG_RST
Embedded Controller Modules (Continued)
Revision 1.07 259 www.national.com
PC87591E/S/L
Flash Data Read Scan
The Flash Data Read Scan instruction switches the data scan path to FL_DATA register. During this instruction, the length
of the scan chain is 18 bits. In the Capture-DR state, the Flash Read Data buffer and the two status bits are loaded into the
shift register and the Valid bit is cleared. The Error bit indicates any error that occurred during the read operation.
If the Valid bit read was cleared, the data and error fields should be ignored. If the Valid bit read was set, the address is
incremented after the Capture-DR state. A data read from the memory is performed, placing the data in the Flash Read Data
buffer and setting the Valid bit.
When the flash address is in the flash main block or Information block, the data read is one word and the address increment
is two.
Flash Data Write Scan
The Flash Data Write Scan instruction switches the data scan path to FL_DATA register. During this instruction, the length
of the scan chain is 18 bits. In the Capture-DR state, the Flash Read Data buffer and the two status bits are loaded into the
shift registers and the Valid bit is cleared. The Error bit indicates any error that occurred during the write operation.
If the Valid bit read was cleared, the data and error fields should be ignored. If the Valid status (RO) bit is cleared and the
Valid control bit is set (WO) during the Update-DR state, the data is loaded into the Flash Write Data buffer, starting the data
write sequence to the flash. When the write is completed, a flash read is performed, placing the data in the Flash Read Data
buffer. The data is then compared to the Flash Write Data buffer; if the two are different, the Program Error flag in the Control
Status register and the Error flags in the data register are set. The Valid bit read (RO) indicates when another word may be
written to the data write buffer.
When the flash address is in the flash main block or Information block, the data written is one word (16 bits) and the address
increment is two.
FMBUSY is set at the beginning (Update-DR) of the write process; it is cleared when the write to the flash is completed. The
Flash error flags are updated in case an error occurs during the write operation.
Flash Erase
The Flash Erase instruction switches the data scan path to FL_ERASE register. During this instruction, the length of the scan
chain is two bits. In the capture-DR state, the Flash Busy and Error bits are read. If the Busy bit is cleared, the Error bit
indicates any failure in the erase process.
During the Update-DR state of this instruction, the Start (WO) bit is loaded into the Control register. If the Start bit and any
of the Erase bits are set, the respective erase process starts. The Flash Address and Block ID are used to indicate the page
or sector to erase in the Page and Sector Erase commands, respectively.
When the erase is completed, the Busy bit is set. The Error flag indicates any failure that occurs in the flash erase procedure.
The FMBUSY and FMERR bits in Flash Status register are updated in parallel to the Erase instruction Busy and Error flags.
Debugger Interface Instructions
SCAN_RX
The SCAN_RX instruction switches the data scan path to DBGDATA register. The DBGDATA length is set to L0 to L4; see
“Debug Data Register (DBGDATA)” on page 261. The result of the Capture-DR state of the TAP controller is unpredictable.
A parallel load of data from DBGDATA register to the DBGRXD Rx data buffer is done in Update-DR state.
The controller sets the RX_BUSY indication in DBGRXST register to 1 in Update-DR state. The PID and message fields of
the SCAN_RX instruction are available for read access, through the peripheral bus, from DBGRXST register. The ISE inter-
rupt control block asserts the ISE interrupt and RX_i bit in DBGISESRC register, according to the PID index.
DEBUGGER ABORT
This operation has no dedicated operation code. It is performed using the SCAN_RX instruction with the PID field is ‘1111’.
Following SCAN_RX mode, the ISE interrupt control block asserts ISE interrupts, together with ABORT_i bits in
DBGISESRC register, according to the MASKS values in DBGMASKS register. The assertion is triggered during the TCK
rising edge during Update-IR state. In this case, there is no RX_BUSY indication and no change in the contents of DB-
GRXST register (i.e., this format of SCAN_RX may be issued with a busy Rx data link).
SCAN_TX
The SCAN_TX instruction switches the data scan path to DBGDATA register. In Capture-DR state, DBGDATA register cap-
tures the values from the Tx data buffer DBGTXD. No parallel load is performed in Update-DR state. The length of
DBGDATA register is set to the value of MSG_LEN in DBGTXST register (see “Debug Data Register (DBGDATA)” on
page 261). No parallel load is performed in Update-DR state.
The Controller sets DBGTXLOC to all 1s and releases TINT on Update-DR state. This operation clears the semaphore and
enables the data link for a new transaction. TINT is asserted, as described in “TX Data Link” on page 250.
Embedded Controller Modules (Continued)
www.national.com 260 Revision1.07
PC87591E/S/L
SCAN_ABORT_MASK
The SCAN_ABORT_MASK instruction switches the data scan path to ABORT_MASK register. In Capture-DR state, a par-
allel update of the shift register occurs with the DBGMASKS values. Parallel load is performed in Update-DR state to update
the DBGMASKS values.
ASSERT_DBG_RST
A Debugger reset is asserted in Update-DR state. Serial data is switched to the BYPASS register.
4.19.7 TAP Data Registers, Debugger Interface
Bit Arrangement and Mapping
Figure 84 shows the bit allocation for a parallel load operation between any pair of serial shift registers and a peripheral bus
addressable register.
Figure 84. Bit Allocation Arrangement
Functionality in Various TAP Controller States
When data is shifted through a data register, data applied to TDI appears without inversion at TDO following an appropriate
number of TCK transitions, when the TAP controller is in Shift-DR state.
The data register connected between TDI and TDO shifts data one stage towards TDO after each rising edge of TCK in
Shift-DR state.
In TAP-Reset state, all data registers either perform their system function (if one exists) or do not interfere with the operation
of the on-chip system logic.
If, in response to the current instruction, a data register loads data from a parallel input, the data is loaded on the rising edge
of TCK following entry into Capture-DR state.
If the data register connected between TDI and TDO in response to the current instruction is provided with latched parallel
data outputs, the data is latched into the parallel output buffers on the falling edge of TCK, during Update-DR or Run-
Test/Idle states, as appropriate.
If, in response to a current instruction, no operation of a selected data register is required in a given controller state, the
register retains its last state unchanged.
When the TAP controller state machine is in TAP-Reset state during Power-Up reset, IR register is reset.
Data registers that are not selected by the current instruction are set to perform their functions, as described in Section 4.19;
specifically, see “TX Data Link” on page 250, “Debugger Reset Circuit” on page 250 and “ISE Interrupt Control” on page 250.
Table 40. Data Register Operation in Each Controller State
Controller State Action
Capture-DR Load data at parallel input into shift register stage. Parallel output registers, or latch, retains last state.
Shift-DR Shift data towards serial output. Parallel output register, or latch where provided, retains state.
Exit1-DR
Exit2-DR
Pause-DR
Retain last state.
Update-DR Load parallel output register or latch from the shift register stage. Shift register stage retains state.
All other controller
states Registers that have a parallel output maintain the last state of this output; otherwise undefined.
15 0 15 0 15 0
15 0 15 0 15 0
TDI TDO
ADD XXXN ADD XXX(N-1) ADD XXX0
Embedded Controller Modules (Continued)
Revision 1.07 261 www.national.com
PC87591E/S/L
Debug Bypass Register (BYPASS)
The BYPASS register provides a minimum length serial path for data movement between TDI and TDO. This path can be
selected when no other data register needs to be accessed.
The BYPASS register consists of a single shift register stage.
When the current instruction selects the BYPASS register for inclusion in the serial path between TDI and TDO, the shift
register stage is set to 0 on the rising edge of TCK following entry into Capture-DR state. The BYPASS register is accessed
from the JTAG serial bus only.
Debug Data Register (DBGDATA)
This register is the shift register element of DBGRXD and DBGTXD. It is accessed from the JTAG serial bus only. Figure 85
shows the parallel load data scheme.
The DBGDATA register consists of shift register stages according to the data buffer length. The actual length of the data value,
in a scan operation, is set before Capture-DR state when the current instruction is SCAN_RX or SCAN_TX. In the first case, it
is set according to SCAN_RX L0 to L4; in the latter case, it is set according to the value of MSG_LEN in DBGTXST register.
The actual length of the register is 16*(length+1), where “length” is the binary positive number created by the length field
(with L4 as MSB).
A length longer than the maximum data buffer is mapped to maximum length. A length shorter than the maximum data buffer
results in loading the data to/from the smallest addresses in the data buffer. Maximum length for this design is 128 shift reg-
ister stages. Note that TDO is always fixed; the TDI “insertion-point” changes according to the actual length.
Figure 85. DBGDATA Connection to the Data Links
Debug Abort Mask Register (DBGMASKS)
This is a serial shift register, with parallel output and parallel input (for read and write of ABORT_MASK register), accessed
by the JTAG serial bus while the SCAN_ABORT_MASK instruction is set to TAP IR. The register is not addressable from
the peripheral bus. The non-reserved bits of ABORT_MASK register are preset to 1 on Power-Up reset.
The ABORT_MASK register consists of shift register stages with 16 bits. Bits 1 to 15 are reserved and should be written with
0. A bit value of 1 enables the processor to abort; a bit value of 0 disables it.
Figure 86. ABORT_MASK and DBGMASKS Register Interaction
15 0 15 0 15 0
15 0 15 0 15 0
TDI TDO
ADD XXE ADD XXC ADD XX0
15 0
15 0
ADD XX2
DBGTXD
DBGDATA
DBGRXD
ADD YYE ADD YYC ADD YY0ADD YY2
15 0 15 0 15 015 0
Length = 1 word
Length = 8 words
15 0
15 0
TDI TDO
ABORT_MASK
DBGMASKS
Embedded Controller Modules (Continued)
www.national.com 262 Revision1.07
PC87591E/S/L
4.19.8 TAP Data Registers, Flash Interface
This section describes the flash interface registers available to the host through the flash interface. The bit ordering is as
described in “TAP Data Registers, Debugger Interface” on page 260.
Flash Control and Status Register (FL_CT_ST)
FL_CT_ST is a shift register that enables reading from the Flash Status register and writing to the Flash Control register.
The Flash Status register is read in Capture-DR state; the Flash Control register is updated in Update-DR state. The con-
nection of the register to the serial chain is shown in Figure 87. The Control and Status registers are reset at Power-Up and
TAP resets only.
Flash Status
Type: Varies per bit
Bit 76543210
Name FMPRGE BLFF FLAEN FMDERR FMBFULL FMBUSY FMPERR FMEERR
Reset 00000100
Bit 15 14 13 12 11 10 9 8
Name JTFIE DISVRF Reserved FMSPERE FMSERE FMPERE
Reset 00000000
Bit Type Description
0 R/W1C FMEERR (Flash Memory Erase Error). Indicates an error in erasing to the flash. It is cleared by
writing 1 to FMEERR bit in the Control register. This bit may be cleared only when FMBUSY bit is
cleared (0).
0: No program error detected (default)
1: An error occurred during erase
This bit may be cleared only when FMBUSY bit is cleared (0).
1 R/W1C FMPERR (Flash Memory Program Error). Indicates an error in writing to the flash. It is cleared by
writing 1 to FMPERR bit in the Control register. This bit may be cleared only when FMBUSY bit is
cleared (0).
0: No program error detected (default)
1: An error occurred during program
2ROFMBUSY (Flash Memory Busy).
0: The embedded flash is ready to accept operations if no error flag is set
1: The embedded flash is not accessible because the PC87591x clocks are not ready or the embedded
flash is busy programing or erasing
3ROFMBFULL (Flash Double-Buffer Full).
0: There is at least one empty word in the flash double buffer
1: The double-buffer is full
Figure 87. Flash Control and Status Register
15 0
TDI TDO
Flash Control Status
15 0
FL_CR_ST
Embedded Controller Modules (Continued)
Revision 1.07 263 www.national.com
PC87591E/S/L
Flash Identification Register (FL_ID)
FL_ID is a shift register that contains device identification information. This information can help to verify the use of the cor-
rect flash programing algorithm and to match downloaded information to the device properties.
Type: Read Only
4 R/W1C FMDERR (Flash Data Loss Error). Indicates that a double-buffer overrun error occurred. The bit is cleared
by writing 1 to FMDERR bit in Control register. It may be cleared only when FMBUSY bit is cleared (0).
0: No data loss detected (default)
1: A write to a full buffer was detected
5ROFLAEN (Flash Access Enabled).
0: The flash memory protection is set; read, write and erase (except special erase) are disabled
1: The flash memory access through the JTAG serial bus is enabled
6ROBLFF (Blank Flash Flag).
0: The Blank Flash flag is cleared and the core is allowed to execute from it
1: The Blank Flash flag is set and the core is kept in reset, even when flash access is enabled
7 R/W FMPRGE (Flash Memory Program Enable).
0: Programing the flash memory using JTAG write instructions is disabled (default)
1: Programing the flash memory using JTAG write instructions is enabled
8 R/W FFMPERE (Flash Memory Page Erase Enable).
0: Flash page erase disabled (default)
1: Flash page erase using the JTAG Erase instruction is enabled
9 R/W FMSERE (Flash Memory Sector Erase Enable).
0: Flash sector erase disabled (default)
1: Flash sector erase using the JTAG Erase instruction is enabled
10 R/W FMSPERE (Flash Memory Special Erase Enable).
0: Flash special erase operation disabled (default)
1: Flash special erase operation using the JTAG Erase instructions is enabled
13-11 Reserved.
14 R/W DISVRF (Disable Verify).
0: Enables verification of flash contents after program or erase (default)
1: Disables the automatic verification of flash contents after program or erase;
this speeds up the program or erase speed.
15 R/W JTFIE (JTAG To Flash Interface Enabled).
0: Flash access through the JTAG is disabled. Write of 1 to any other bit in this register is ignored, all
error flags are cleared, and all other JTAG access flash transactions are ignored (i.e., Capture-DR re-
turns invalid data, Update-DR is ignored) (default).
1: Interface to the flash through the JTAG is enabled
Bit 31 30 29 28 27 26 25 24 23 2 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Name Reserved SRID SID
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ID values
Bit Type Description
Figure 88. Flash Identification Register
32 0
TDI TDO
SID
70
FL_ID
SRID
70
15 0
Reserved
Embedded Controller Modules (Continued)
www.national.com 264 Revision1.07
PC87591E/S/L
Flash Address Register (FL_ADDR)
FL_ADDR is a shift register that enables reading from and writing to flash addresses. The address includes two fields: the
Flash Address and the Block Identifier (main block or information block). In Capture-DR state, the next address for read
and/or program is read. In case of a program or page erase fail, the offset within the section of the failing memory location
is returned. In Update-DR state, the address register is loaded with a new address. The connection of the register to the
serial chain is shown in Figure 89. The address register is reset at Power-Up and TAP resets only.
Type: R/W
Bit Description
7-0 SID (SuperI/O Identification). Returns the value of SID register (see “SuperI/O ID Register (SID)” on page 344)
15-8 SRID (SuperI/O Revision ID). Returns the value of SID register (see “SuperI/O Revision ID Register (SRID)” on
page 346)
31-16 Reserved.
Bit 31302928272625242322120191817161514131211109876543210
Name Block ID Flash Address
Reset 0 0
Bit Type Description
27-0 R/W Flash Address. Holds the flash address in bytes, starting from address 0000016. The flash last address
depends on the block size. All addresses must be word aligned. Note that the field may hold values larger
than the actual flash size. Addresses beyond the flash size are reserved and should not be specified.
31-28 R/W Block ID. Holds an ID for a specific block. The ID field values are:
Bits
31 30 29 28 Description
0 0 0 0: For Capture-DR,reserved; for Update-DR, noload of Addressand Block IDregisters (default)
0 0 0 1: Flash Main Block
0 0 1 0: Flash Information Block
Other: Reserved
Figure 89. Flash Address Register
0
TDI TDO
Flash Address
27 0
FL_ADDR
Block ID
30
31
Embedded Controller Modules (Continued)
Revision 1.07 265 www.national.com
PC87591E/S/L
Flash Data Register (FL_DATA)
FL_DATA is a shift register that enables scanning data for flash read and write. This register is used during both flash pro-
graming and flash read. It includes two fields: a 16-bit data field and two Control/Status bits. In Capture-DR state, data read
from the array (for either a read instruction or as a confirmation of a write cycle) is loaded from the Flash Read buffer into
FL_DATA register. The Valid and Error bits indicate if program and read operations are successfully completed. In Update-
DR state, data is loaded into the Flash Write Data buffer if the Valid bit in the data shifted in is set. The connection of the
register to the serial chain is shown in Figure 89. The address register is reset at Power-Up and TAP resets only.
Type: Varies per bit
Bit 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Name Error Valid Data
Reset
Bit Type Description
15-0 R/W Data. In read, returns the data read from the flash memory. Following a previous read instruction or a
set address, the data is read from the array with the currently held address. Following a previous write
instruction, the data is read back from the array as part of the write verification.
During write instruction, data scanned into this field, if the Valid bit is set, is loaded into the Flash Write
Data buffer and used for the next flash programing action.
16 RO
WO
Valid. Indicates that the data read or written is valid.
On Read (Capture-DR):
0: Data is not valid, since the read was not completed or the write buffer is not ready to accept new data.
1: Indicates that data in the Data Read buffer is valid. This data may be the result of a read (following a
previous read instruction) or the result of a failed write. Note that when a 1 is read from this bit, it is
automatically cleared to 0. In a read instruction, a read of 1 triggers a new read operation from memory
with the successive address.
During flash write sequences, indicates that the write data buffer is ready to accept new data; the bit
is cleared when new data is written to the buffer.
On Write (Update-DR): This bit must be written with 0 during a read instruction or when the flash is not
ready to accept new data (i.e., when the Valid bit in the Capture-DR is cleared).
0: Data is not valid. Do not update the Flash Data Write buffer.
1: Indicates that valid data is written to the Flash Data Write buffer. In write instruction, this triggers the
flash to be programed with new data.
17 RO Error. Indicates that an error occurred during the last programing cycle. The bit is set when the error
is detected.
0: Last write was completed successfully (default)
1: An error was detected during the last write. This may be due to a failed write, a double buffer error or
to an attempt to violate restrictions put by the flash contents protection mechanism. For more details
about the error type, see “Flash Control and Status Register (FL_CT_ST)” on page 262.
When set, the error is cleared by clearing any set error flag in FL_CT_ST register.
Figure 90. Flash Data Register
17 0
TDI TDO
Flash Read Data Buffer
Flash Write Data Buffer
FL_DATA
Status
Control
15 0
10
10
Embedded Controller Modules (Continued)
www.national.com 266 Revision1.07
PC87591E/S/L
Flash Erase Register (FL_ERASE)
FL_ERASE is a shift register that starts a flash erase operation and returns the status of the erase operation. The type of
erase performed depends on the settings in the Control and Status register. The connection of the register to the serial chain
is shown in Figure 91. The FL_ERASE register is reset at Power-Up and TAP resets only.
Type: Varies per bit
Bit 1 0
Name Error Start/Busy
Reset 0 0
Bit Type Description
0RO
WO
Busy. On read (Capture-DR), indicates the status of the flash array.
0: Flash is idle and is ready for an erase command to be started
1: Flash is busy executing a previous erase or write command; any command given at this state is ig-
nored.
Start. On write (Update-DR), starts a flash erase process.
0: Do not start a new erase process
1: Start a new erase process
1ROError. Indicates that an error occurred during the last erase cycle. This bit has valid data only when the
Busy bit is cleared.
0: Last erase was completed successfully (default)
1: An error was detected during the last erase. This may be due either to a failed erase or protection be-
ing set. More details about the error type are available by reading the Control and Status register.
When a value of 1 is read, this bit is cleared.
Figure 91. Flash Erase Register
10
TDI TDO
10
Status
10
Control
FL_ERASE
Embedded Controller Modules (Continued)
Revision 1.07 267 www.national.com
PC87591E/S/L
4.19.9 Core Registers, Debugger Interface
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
Core Register Map
Debug Receive Data Registers 0, 2, 4, 6, 8, 10, 12 and 14 (DBGRXD0-14)
DBGRXD0 to DBGRXD14 is a group of eight word-wide read-only registers. The DBGRXD0-14 registers are written from
the JTAG serial bus. They can only be read from the peripheral bus. A representative DBGRXDi register is shown below.
Location: Channel 0 - 00 FDC016
Channel 2 - 00 FDC216
Channel 4 - 00 FDC416
Channel 6 - 00 FDC616
Channel 8 - 00 FDC816
Channel 10 - 00 FDCA16
Channel 12 - 00 FDCC16
Channel 14 - 00 FDCE16
Type: RO
Mnemonic Register Name Type
DBGRXD0-14 Debug Receive Data Registers 0, 2, 4, 6, 8, 10, 12 and 14 RO
DBGRXST Debug Receive Status Register Varies per bit
DBGTXD0-14 Debug Transmit Data Registers 0, 2, 4, 6, 8, 10, 12 and 14 R/W
DBGTXLOC Debug Transmit Lock Register R/W
DBGTXST Debug Transmit Status Register R/W
DBGTINT Debug TINT Assert Register WO
DBGABORT Debug Abort Generate Register WO
DBGISESRCA Debug ISE Source Register A R/W
Bit 1514131211109876543210
Name RX_DATAi
Bit Description
15-0 Receive Data (RX_DATA). Data bits 16*i through 16*i+15 of the Rx data link data buffer.
15 0
Embedded Controller Modules (Continued)
www.national.com 268 Revision1.07
PC87591E/S/L
Debug Receive Status Register (DBGRXST)
DBGRXST is a byte-wide register updated by the TAP controller to reflect the PID and MSG_LEN fields of the SCAN_RX
instruction. Bits 1 to 7 of this register are read-only bits; data written to them is ignored. The register format is shown below.
Location: 00 FDE016
Type: Varies per bit
Debug Transmit Data Registers 0, 2, 4, 6, 8, 10, 12 and 14 (DBGTXD0-14)
DBGTXD0 to DBGTXD14 is a group of eight word-wide read/write registers. The DBGTXD0-14 registers are written by a
processor from the peripheral bus. A representative DBGTXDi register is shown below.
Location: Channel 0 - 00 FDD016
Channel 2 - 00 FDD216
Channel 4 - 00 FDD416
Channel 6 - 00 FDD616
Channel 8 - 00 FDD816
Channel 10 - 00 FDDA16
Channel 12 - 00 FDDC16
Channel 14 - 00 FDDE16
Type: R/W
Bit 76543210
Name MSG_LEN PID RX_BUSY
Bit Type Description
0 R/W RX_BUSY (Receive Busy). Data link busy indication. This bit can be cleared by writing 1 to it. Writing
0 is ignored.
0: Not Busy
1: Busy
4-1 RO PID (Processor Index). A write operation to this field is ignored.
Bit Value
(Decimal) Description
0: Processor ID index
1-14: Invalid
15: All processors abort
7-5 RO MSG_LEN. The message length equals (MSG_LEN+1). Write operations to this field are ignored.
Bit 1514131211109876543210
Name TX_DATAi
Bit Description
15-0 TX_DATAi (Transmit Data i). Data bits i*16 through i*16+15 of the transmit buffer.
Embedded Controller Modules (Continued)
Revision 1.07 269 www.national.com
PC87591E/S/L
Debug Transmit Lock Register (DBGTXLOC)
DBGTXLOC is a byte-wide read/write register. The PID field of this register is used as a semaphore for locking the Tx chan-
nel for a specific processor. If TINT is not active (1), this register is loaded with F16 on Warm or Internal reset. If TINT is
active (0), it is not affected by a Warm or Internal reset. At Power-Up reset, the register is always loaded with 0F16. The
register format is shown below.
Location: 00 FDE416
Type: R/W
Debug Transmit Status Register (DBGTXST)
DBGTXST is a byte-wide read/write register. This register is written by a processor to indicate the message length, which is
used by the Tx data link to set the length of the serial shift register and by the processor software to define the message
length parameter. While TINT is inactive, this register may be written to at any time. While TINT is active, the contents of
this register are locked and can be read by the host via the TAP controller status word MSG_LEN field. While TINT is inac-
tive, DBGTXST is cleared on reset. While TINT is active, only Power-Up reset clears DBGTXST. The register format is
shown below.
Location: 00 FDE216
Type: R/W
Bit 76543210
Name Reserved PID
Reset 0 0 001111
Bit Description
3-0 PID (Processor Index). Indicates which processor currently has control over the Tx channel. When TINT
becomes active, the value of PID is locked. On the Update_DR state of SCAN_TX instruction, PID is reset to
F16 after the host reads the data.
016-E16: Processor ID index. When the PID field holds any of these values, write operations of values other
than F16 are ignored.
F16: Semaphore free indication. When the PID field holds this value, write operations may capture the Tx
for processor use.
7-4 Reserved.
Bit 76543210
Name Reserved MSG_LEN
Bit 00000000
Bit Description
2-0 MSG_LEN (Message Length). The number of words in a message equals (MSG_LEN+1).
7-3 Reserved.
Embedded Controller Modules (Continued)
www.national.com 270 Revision1.07
PC87591E/S/L
Debug TINT Assert Register (DBGTINT)
This is a byte-wide write-only register used to assert TINT. The register format is shown below.
Location: 00 FDE616
Type: WO
Debug Abort Generate Register (DBGABORT)
DBGABORT is a word-wide write-only register, used to generate an ABORT. A processor may generate an ABORT to a
processor with a PID index of i by modifying its P_i bit to 1. Writing 0 to P_i does not result in ISE assertion. The register
format is shown below.
Location: 00 FDE816
Type: WO
Bit 76543210
Name Reserved ASSERT
Bit Description
0ASSERT (Assert TINT Control). Writing 1 to this bit asserts the TINT output. TINT is de-asserted during
Update_DR state of SCAN_TX or during Power-Up reset.
7-1 Reserved.
Bit 1514131211109876543210
Name Reserved Res Res Res Res Res Res Res P_0
Bit Type Description
0WOP_0. The ABORT source activation.
0: Processor ID i does not get an ABORT
1: Processor ID i gets an ABORT
15-1 Reserved. Reserved for future expansion.
Embedded Controller Modules (Continued)
Revision 1.07 271 www.national.com
PC87591E/S/L
Debug ISE Source Registers A (DBGISESRCA)
DBGISESRCA is a word-wide read/write register that indicates the ISE sources. The register is cleared on reset. Writing 1
to a bit in this register clears it. Writing 0 to a bit does not change its value. The DBGISESRCA register format is shown
below.
Location: 00 FDEA16
Type: R/W S
4.19.10 Usage Hints
JTAG Performance
For best performance, the PC87591x should be the only device in the scan path. Since the Debugger interface is used in
the development phase of the product, this should not be a problem. Keep the scan path as short as possible.
JTAG Clock Rate
For reliable communication over the JTAG serial bus, the error probability should be extremely low. This can be achieved
by connecting the TAP to the JTAG bus controller card, paying attention to the TCK frequency, signal timing, this cable type
and cable length (for long cables, transceivers may be required).
Communication Lockout
Some erroneous operations by the host may cause a lockout of the communication hardware. Examples of such cases are:
Performing a data scan when the JTAG instruction is SCAN_RX with a PID value of ‘1111’
Performing a data scan with a JTAG instruction with a PID value that is not in the system (i.e., PID > 0)
Performing a SCAN_TX when the PID value is ‘1111’
A reset instruction is guaranteed to recover from all of these locked cases, but it resets the entire PC87591x.
Bit 15 14 13 12 11 10 9 8
Name Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved
Reset 00000000
Bit 76543210
Name Reserved ABORT_0 RX_0
Reset 00000000
Bit Description
0RX_i. The ISE source is the Rx data link. Turn on with ISE assertion. Turn off by writing a byte to DBGISESRC
containing 1 in the RX_i bit location.
0: Not an ISE source
1: The ISE source is the Rx data link
1ABORT_i. The ISE source is an ABORT request by the debugger or one of the processors. This bit is set by
either an abort command from the debugger (SCAN_RX with PID=‘1111’) or by a write of a 1 to the processor’s
respective bit in DBGISECA register.
0: Not an ISE source
1: The ISE source is an ABORT event
7-2 Reserved. These bits are reserved for future expansion.
Embedded Controller Modules (Continued)
www.national.com 272 Revision1.07
PC87591E/S/L
4.20 DEVELOPMENT SYSTEM SUPPORT
The PC87591x supports code development and debug in the On Board Development (OBD) and Development (DEV) envi-
ronments. OBD environment is used for debug of the code in the final production board. DEV environment is used in Appli-
cation Development Boards (ADBs) and ISE systems.
4.20.1 Features
ISE clipping support via a TRI-STATE strap input (TRIS)
Features available in OBD and DEV environments:
Debugger interface via the JTAG based Debugger Interface module
Internal ISE interrupt generation by the Debugger Interface module
Internal Reset generation by the Debugger Interface module
Ability to prevent real-time events from interfering with operation of ADB monitor
Core-integrated hardware breakpoint
Features available in DEV environment:
Optional use of break line input signal
Status Information to trace internal activities and implement debug features such as hardware breakpoint and traces
Use of SRAM in the ADB for fast download of code during development
Feature available in OBD environment:
Use of on-chip flash for executing the final code
4.20.2 The ISE Interrupt
The core ISE interrupt is an edge-triggered, non-maskable interrupt that is triggered on the rising edge of the Debugger in-
terface output. The ISE interrupt is asserted by the Debugger Interface module for RX or ABORT events to the core.
The ISE interrupt is enabled in DEV and OBD environments when ON bit in DBGCFG register is set to 1; otherwise, it is held
inactive.
4.20.3 Break Line and Reset Output Interrupt
The BRKL_RSTO signal is available in DEV environment. It has two functions: BRKL interrupt input and RSTO reset indi-
cation. Multiplexing between the two functions is done based on bus activity as defined below.
BRKL Function
The BRKL interrupt input is enabled in DEV environment when ON and BRKLE in DBGCFG register are both set (1); other-
wise, it is held inactive.
When BRKL is active during an instruction fetch, it indicates to the core a request to break on the execution of the instruction
(if the instruction is to be executed). This enables implementing multiple hardware breakpoints using external hardware.
RSTO Function
RSTO is a pulse output that is driven low when the PC87591x is in reset due to any of its sources (i.e., any reset to the core).
This output may be used to set any required defaults in the development system.
RSTO and BRKL Selection
The BRKL_RSTO signal serves as input to the PC87591x whenever there is activity on the bus i.e., while either SELIO,
SEL0 or SEL1 are active. If SELIO, SEL0 or SEL1 are inactive, the system must stop driving the BRKL_RSTO signal and
hold it high using a pull-up resistor.
When there is no activity on the bus, BRKL_RSTO may serve as output. It is driven low during an internal reset. There may
be a delay from reset start to the signal being driven low, but it is guaranteed to be low for at least three CLK cycles.
4.20.4 TRIS Strap Input Pin
The TRIS strap input signal is used by ISEs to allow clipping on a PC87591x while it is mounted in the production system.
The TRIS input is sampled at VCC Power-Up reset while the device is in IRE or OBD environments. When TRIS is low (0),
the PC87591x acts normally. When TRIS is high (1), all PC87591x outputs, except for DAC outputs and 32KX2, are put in
TRI-STATE.
Section 2.3 on page 53 describes the strap input handling.
Embedded Controller Modules (Continued)
Revision 1.07 273 www.national.com
PC87591E/S/L
4.20.5 Freezing Events
The PC87591x can prevent real-time events from interfering with the operation of the ADB monitor and changing the status
of the PC87591x. This is done by disabling maskable interrupts and setting FREEZE bit; the FREEZE bit freezes the
WATCHDOG counter and disables destructive read operations.
Disabling Maskable Interrupts
Clearing the core I or E bits in PSR register disables the maskable interrupts. The I bit is cleared automatically whenever a
trap or interrupt occurs and after reset.
Freezing the WATCHDOG Counter
To freeze the WATCHDOG counter, FREEZE bit in DBGCFG register must be set to 1 on entering a TMON routine (the bit
must be cleared before returning to the application). Setting FREEZE bit prevents the WATCHDOG from generating the re-
set that occurs if WATCHDOG is not cleared on time (see Section 4.10 on page 164). The WATCHDOG counter keeps its
value while it is frozen and resumes counting after FREEZE is cleared.
If an application fails to touch the WATCHDOG in time and a reset event is generated before or while FREEZE bit is set, the
PC87591x receives the reset.
Disabling Additional Modules
The two MFT16 and the two ACB modules may be frozen by the FREEZE bit. Freezing is enabled when the respective bit
in DBGFRZEN register is set; the bits can be set to meet specific needs of different applications.
Disabling Destructive Reads
When FREEZE in DBGCFG register is set (1), destructive reads do not change the system state (i.e., they return the read
data but do not clear or set bits or send signals). This allows the debugger to present the values of these bits. NMISTAT is
an exception to this rule and is not affected by FREEZE. Core accesses to Host domain registers (using the “Core Access
to Host Controlled Modules”) may also be destructive but are not affected by FREEZE. Note that host operations continue
without any FREEZE bit impact.
4.20.6 Monitoring Activity During Development
In DEV environment, information is available for monitoring on-chip activities and implementing debug features in the devel-
opment system.
Bus Status Signals
The Bus Status signals (BST2-0) indicate if a transaction on the core bus was issued and, if so, the type of transaction.
The BST2-0 signals reflect activity on the core bus. For word accesses involving 8-bit expansion memory, the core bus cycle
triggers two external bus cycles. The first external bus cycle is flagged as a T1 cycle of the core bus. The second is not
flagged as a T1 cycle, i.e., BST2-0 is 000. See Table 41.
Table 41. Core Bus Transaction Encoding
BST Core Bus Transaction Type
000 Not a T1 cycle, except when the core waits for an
interrupt following WAIT instruction execution
001 Core waits for an interrupt following WAIT
instruction execution
010 T1 of an interrupt acknowledge bus cycle
011 T1 of a data transfer of a non-core bus master
100 T1 of a sequential instruction fetch
101 T1 of a non-sequential instruction fetch
110 T1 of a core data transfer
111 T1 of an exception data transfer
Embedded Controller Modules (Continued)
www.national.com 274 Revision1.07
PC87591E/S/L
Transaction Effect on the External Bus
The following core bus transactions are reflected on the external bus:
Accesses to external zones of expansion memory, off-chip base memory and accesses that use the I/O Expansion
protocol are indicated by the active state of the SEL0, SEL1 and SELIO signals, respectively, and are described by
the address and data buses and the status signals, BST2-0.
Accesses to on-chip memories and peripheral modules can be observed using the “Core Bus Monitoring Bus Cycles”
(see “Core Bus Monitoring” on page 82). They accesses are indicated by an inactive state for the SEL0, SEL1 and/or
SELIO signals. They are described by addresses A0-19, the byte-enable BE0-1 signals, the CBRD signal and the
BST2-0 signals.
BE0 is high when a lower memory byte (a byte in an even address) is accessed. BE1 is high when a higher memory
byte (a byte in an odd address) is accessed.
CBRD is high when the transaction is a read operation and low when it is a write operation.
Pipe Status Signals (PFS and PLI)
The PFS indicates the completion of an instruction in the core. The Pipe Long Instruction (PLI) signal indicates the size of
the completed instruction, where 0 = word instruction and 1 = double-word instruction (see Figure 92). If an instruction flush-
es the pipeline, the fetch for the next instruction (BST=101) is issued during the cycle following the instruction’s PFS, or later.
4.20.7 On-Chip Hardware Breakpoint
The core provides two types of hardware breakpoints:
Address Match - Detection of a matched address for the current executed instruction (PC value)
Data Match - Detection of a read or write transaction for a matched memory location
For a detailed description of the core breakpoint mechanism, refer to the CR16B User Manual.
CLK
PFS
PLI
Instruction i
Completed Instruction i+1
Completed
Figure 92. Pipe Status Signal (PFS and PLI)
Embedded Controller Modules (Continued)
Revision 1.07 275 www.national.com
PC87591E/S/L
4.20.8 CR16B Development Support Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
CR16B Development Support Register Map
Debug Configuration Register (DBGCFG)
The DBGCFG register controls the configuration of debug support features. On reset, DBGCFG is cleared (0).
Only the software development tools may access DBGCFG. This enables application software to be binary compatible in all
environments.
Location: 00 FF1616
Type: R/W
Mnemonic Register Name Type
DBGCFG Debug Configuration R/W
DBGFRZEN Debug Freeze Enable R/W
Bit 76543210
Name Reserved BRKLE FREEZE ON
Reset 00000000
Bit Description
0ON.
0: In IRE environment, this bit is always cleared to 0; any data written to it is ignored. The ON bit becomes read-
only when DBGL bit in DCR register in the core is set.
1: In OBD and DEV environments, enables the following debug support features:
- ISE interrupt signal
- Use of other bits in DBGCFG register
1FREEZE.
0: No effect
1: When ON is 1, the WATCHDOG timer is stopped from counting. All bits that use destructive reads (i.e., bits set
or cleared by read operations and other events triggered by reads) become indifferent to reads. An exception
is NMISTAT register, which is always affected by reads. The DBGFRZEN register controls the impact of
FREEZE bit on a group of modules, enabling the group to be indifferent to the FREEZE being set. FREEZE has
no effect when ON is 0.
2BRKLE (Break Line Enable).
0: Break Line input is ignored by core
1: In DEV environment, when BRKLE is set, the BRKL input signal is passed to the core
7-3 Reserved.
Embedded Controller Modules (Continued)
www.national.com 276 Revision1.07
PC87591E/S/L
Debug Freeze Enable Register (DBGFRZEN)
The DBGFRZEN register enables the freeze operation to be performed on specific modules during debug. When the rele-
vant bit is set, it enables the freeze of activities in the respective module when both FREEZE and ON are set in DBGCFG
register. On reset, DBGFRZEN is loaded with FF16.
Location: 00 FF1816
Type: R/W
Bit 76543210
Name Reserved HIFEN USARTFEN ACB2FEN ACB1FEN MFT2FEN MFT1FEN
Reset 11111111
Bit Description
0MFT1FEN (MFT16 1 Freeze Enable).
0: FREEZE in DBGCFG register has no effect on the MFT16 1
1: Freezes the MFT16 1 when FREEZE is set
1MFT2FEN (MFT16 2 Freeze Enable).
0: FREEZE in DBGCFG register has no effect on the MFT16 2
1: Freezes the MFT16 2 when FREEZE is set
2ACB1FEN (ACB1 Freeze Enable).
0: FREEZE in DBGCFG register has no effect on the ACB 1 interface
1: Freezes the ACB 1 interface when FREEZE is set
3ACB2FEN (ACB2 Freeze Enable).
0: FREEZE in DBGCFG register has no effect on the ACB 2 interface
1: Freezes the ACB 2 interface when FREEZE is set
4USARTFEN (USART Freeze Enable).
0: FREEZE in DBGCFG register has no effect on the USART interface
1: Freezes the USART interface when FREEZE is set
5HIFEN (Host Interface Freeze Enable).
0: FREEZE in DBGCFG register has no effect on the Host Interface module
1: Freezes the Host interface when FREEZE is set
7-6 Reserved.
Revision 1.07 277 www.national.com
PC87591E/S/L
5.0 Host Controller Interface Modules
This chapter describes functions that serve as an interface between the host and core domains. The functions are:
Keyboard and Mouse Controller Interface (legacy 6016,64
16); see Section 5.1
Two Power Management (PM) channels compliant with ACPI EC specifications; see Section 5.2 on page 285
Shared Memory mechanism; see Section 5.3 on page 297
Core Access to SuperI/O modules; see Section 5.4 on page 313
Mobile System Wake-Up functions; see Section 5.5 on page 318
5.1 KEYBOARD AND MOUSE CONTROLLER INTERFACE
The PC87591x supports a standard Keyboard and Mouse Controller interface. This interface implements legacy ports 6016
and 6416.
5.1.1 Features
Intel 8051SL-compatible Host interface
8042 KBD standard interface (ports 6016, 6416)
Legacy IRQ: IRQ1 (KBD) and IRQ12 (mouse) support
Fast Gate A20 and Fast Reset via firmware
Configured using two logical devices: Keyboard and Mouse
5.1.2 General Description
The PC87591x supports a keyboard/mouse communication channel that uses the standard command/status register and
data registers. It uses either polling- or interrupt-driven communication schemes with the host and/or core. The hardware is
designed to allow a race-free interface between the host and the PC87591x.
The keyboard and mouse channel consists of three registers:
DBBOUT - can be written by the core and read by the host processor.
DBBIN - can be written by the host processor and read by the core.
STATUS - can be read by both core and host processors. It has five bits (2, 4-7) that are written by the core. Three
other bits are controlled by the hardware to indicate the status of DBBIN and DBBOUT registers.
Host Addresses
The host processor accesses the PC87591x Keyboard/Mouse Host Interface registers at two addresses in the host address
space. These addresses are defined by two internal chip-select signals specified in the PC87591x host configuration regis-
ters; see Section 6.1.10 on page 348). Legacy settings of these addresses are 6016 and 6416 for the status/command and
data registers, respectively.
Table 42 describes the register mapping to the host processor I/O space. For simplicity, the Host Interface module specifi-
cation refers to the legacy addresses.
Table 42. Mapping of the Host Interface Registers to the Host Processor
Core Interrupts
The Host Interface module generates four level (high) interrupts to the core ICU. These can be used by the firmware for
interrupt-driven control of the keyboard/mouse and/or PM channels.
Host Interrupts
The PC87591x Host Interface supports two interrupts to the host processor: Keyboard interrupt (legacy IRQ1) and Mouse
interrupt (legacy IRQ12). These interrupts may be controlled by hardware according to the host interface buffer status or by
the PC87591x firmware toggling the bit value.
Port Legacy
Address Internal Chip Select Type Register Name Mnemonic
Keyboard and
Mouse 6016 Keyboard/Mouse Data Write Data DBBIN (A2=0)
6416 Keyboard/Mouse Command Write Command DBBIN (A2=1)
6016 Keyboard/Mouse Data Read Data DBBOUT
6416 Keyboard/Mouse Command Read Status STATUS
5.0 Host Controller Interface Modules (Continued)
www.national.com 278 Revision1.07
PC87591E/S/L
The Host configuration module assigns host interrupts to IRQ numbers (see Section 6.1.10 on page 348). These interrupts
are IRQ1 and IRQ12 for keyboard and mouse IRQs, respectively.
When IRQ1 and/or IRQ12 are disabled (OBFKIE and/or OBFMIE bits in HICTRL register are cleared), the firmware can con-
trol the IRQ1 and/or IRQ12 signals by writing to the signal’s respective bit in HIIRQC register.
When IRQ1 and/or IRQ12 are controlled by hardware (OBFKIE and/or OBFMIE bits in HICTRL register are set to 1), inter-
rupts to the host are generated according to the status of Output Buffer Full (OBF) flag.
In normal polarity mode (IRQNPOL in HIIRQC register is set to 0), the PC87591x supports two types of interrupts: Legacy
Edge and Level. When an Edge interrupt is selected (IRQM in HIIRQC register is set), the interrupt signal default value is
high (1). When an interrupt signal must be sent (i.e., the corresponding OBF flag is set), a negative pulse is generated. The
pulse width is determined by IRQM field in HIIRQC register.
When the IRQ signals are set as level interrupts (IRQM in HIIRQC register is set to 0), the interrupt signal is usually low (0)
and is asserted (1) to indicate that the respective OBF flag is set. The signal is de-asserted (0) when the output buffer is read
(i.e., OBF flag is cleared).
Note that IRQ1 and IRQ12 have the same OBF flag but are not asserted together. Either IRQ1 or IRQ12 is set, depending
on the internal register written (HIKDO or HIMDO, respectively).
In negative polarity mode (IRQNPOL in HIIRQC register is set to1), the IRQ signal behavior is inverted from the behavior
described above.
The PC87591x firmware can read the values of the IRQ1 and IRQ12 signals by performing a read operation from IRQ1B
and IRQ12B bits in HIIRQC register.
Figure 93 illustrates the effect of the different control bits on the IRQ signals.
Figure 93. IRQx (IRQ1, IRQ11 or IRQ12) Control Diagram
Keyboard/Mouse Channel (6016, 6416)
The Host Interface of the PC87591x is compatible with the legacy 8042 host interface. It is based on two registers: Com-
mand/Data and Status. The Host Interface logic generates interrupts to the host processor and core according to the status
of the input and output data buffers. Figure 94 provides a schematic description of the Host Interface Keyboard/Mouse chan-
nel.
Hardware
IRQM field (HIIRQ)
Interrupt
IRQNPOL bit (HIIRQC)
1
0
IRQxB bit (HIIRQC)
OBFMIE or OBFKIE bit
1
0
(HICTRL)
IRQxB bit (HIIRQC)
IRQxB bit (HIIRQC)
(write) (Part of SuperI/O
Configuration
Module)
IRQ Routing
and Polarity
IRQ Serializer IRQ
Serializer
(read)
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 279 www.national.com
PC87591E/S/L
Status Read
Both the host and the core can read the status of the KBC data buffers. Bits 2 and 4 to 7 can be written by the core. The
host processor should read address 6416 to obtain the contents of the Status register. The core software can obtain this
information by reading/writing the HIKMST register. The format of the Status register is identical for both the host and the
core (see “Host Interface Keyboard/Mouse Status Register (HIKMST)” on page 284).
Host Data Write to Host Interface Keyboard/Mouse Channel
The data buffer has two latches; one serves as an input buffer and the other as an output buffer. When writing to address
6016 or 6416, the following sequence of events occurs: the data is written to the Data In latch (DBBIN), IBF bit in the Status
register is set and bit 3 (A2) in the Status register indicates to the core which address (command or data) was written to.
When writing to address 6016 (legacy A2=0), bit 3 of the Status register is cleared. When writing to address 6416 (legacy
A2=1), bit 3 of the Status register is set.
The core identifies that data is present in the input buffer by either polling IBF bit of the Status register or acknowledging an
interrupt when the input buffer interrupt is enabled (IBFCIE in HICTRL register is set to 1).
When the input buffer is full, reading the Status register identifies which address was written to (i.e., check A2 of HIKMST
register). The core can then read the data from the input buffer (HIKMDI). The IBF status bit is cleared when the data input
buffer is read by the core.
Host Data Read from Host Interface Keyboard/Mouse Channel
The output data latch (DBBOUT) is written by the core when it needs to send data to the host. The OBF flag in the Status
register (OBF in HIKMST register) is set to indicate that data is available in DBBOUT. DBBOUT should be written only when
this bit is cleared.
The PC87591x supports polling and interrupt communication schemes with the host. Both Keyboard interrupt (IRQ1) and
Mouse interrupt (IRQ12) are supported.
The core firmware writes to HIKDO register data addressed to the keyboard driver (i.e., generate IRQ1). A write to HIKDO
stores the data to DBBOUT and sets OBF bit. If the IRQ1 interrupt is enabled (OBFKIE in HICTRL register is set to 1), it is
also sent according to the interrupt mode (IRQM field and IRQNPOL bit in HIIRQC register).
The core firmware writes data addressed to the mouse driver (IRQ12) to HIMDO register. A write to HIMDO stores the data
in DBBOUT and sets OBF bit. If the IRQ12 interrupt is enabled (OBFMIE in HICTRL is set to 1); the IRQ12 interrupt is also
sent according to the interrupt mode (IRQM field and IRQNPOL bit in HIIRQC register).
DBBIN
DBBOUT
STATUS
D0-7
D0-7 A2
Host-WR-Data-Buffer
Host-RD-Data-Buffer
WR-Mouse WR-KBD RD-Input
Buffer
Input Buffer
Full
Output Buffer
Empty
Interrupts to the Core
(IRQ1)
Peripheral Bus
SIB Bus
Interrupts to the Host Processor
Figure 94. Host Interface Keyboard/Mouse Channel (Ports 60,64) Block Diagram
Keyboard Mouse
(IRQ12)
through SuperI/O Configuration
Interrupt Request Interrupt Request
5.0 Host Controller Interface Modules (Continued)
www.national.com 280 Revision1.07
PC87591E/S/L
The host processor identifies that data is present in the output buffer by either polling the Status register (reading address
6416) or responding to IRQ1 or IRQ12. When this data is available, the host can read it using a read operation from address
6016. Reading from address 6016 clears the OBF flag. In addition, when the host interrupt is in level mode (IRQM in HIIRQC
register is set to 0002) and the hardware interrupt is enabled, IRQ1 or IRQ12 are de-asserted (low if IRQNPOL in HIIRQC
register is set to 0).
The core can read OBF bit to identify when the output buffer is empty and ready for a new data transfer. When the Output
Buffer Empty interrupt to the core is enabled (OBECIE in HICTRL register is set to 1), the interrupt signal to the ICU is set
high if the output buffer is empty (OBF=0).
5.1.3 Host Interface Registers
The module has four registers, described below. The base address for each may be configured individually. For legacy op-
eration, they should be configured to 6016 and 6416 (see Section 6.1.10 on page 348).
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
Host Interface Register Map
Data Out Buffer Register (DBBOUT, Legacy 6016)
This register allows the host to read DBBOUT register while clearing OBF bit in the Status register. If the host interrupts are
level (IRQM in HIIRQC register is 0002), the interrupt is de-asserted. If the core interrupt on output buffer empty is enabled
(OBECIE in HICTRL register is set to 1), reading this register asserts it (high).
Location: As defined in LDN 0616 registers, index 6016 and 6116
Type: R
Offset Mnemonic Register Name Type
6016 DBBOUT Data Out Buffer R
6416 STATUS Status R
6016 DBBIN Data In Buffer W
6416 COMAND Command In Buffer W
Bit 76543210
Name Keyboard/Mouse DBBOUT Data
Bit Description
7-0 Keyboard/Mouse DBBOUT Data.
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 281 www.national.com
PC87591E/S/L
Status Register (STATUS, Legacy 6416)
This register provides the status of the host interface keyboard channel buffers (DBBIN and DBBOUT) and the value of mes-
sages sent by the core using the Status bits to the host. The Status register can also be read by the core as HIKMST. The
Status register is cleared (0016) on reset.
Location: As defined in LDN 0616 registers, index 6216 and 6316
Type: R
Data In Buffer Register (DBBIN, Legacy 6016)
This register allows the host to write to DBBIN register while setting Status register bit IBF and clearing Status register bit
A2 bit. If the core interrupt on IBF is enabled (IBFCIE in HICTRL register is set to 1), writing to this register asserts it (high).
Location: As defined in LDN 0616 registers, index 6016 and 6116
Type: W
Command In Buffer Register (COMAND, Legacy 6416)
This register allows the host to write to DBBIN register while setting IBF and A2 bits in the Status register. If the core interrupt
on IBF is enabled (IBFCIE in HICTRL register is set to 1), writing to Data In Buffer asserts it (high).
Location: As defined in LDN 0616 registers, index 6216 and 6316
Type: W
Bit 76543210
Name ST3-ST0 A2 F0 IBF OBF
Reset 00000000
Bit Description
0OBF (Output Buffer Full). The bit is set when the keyboard/mouse channel’s DBBOUT is written to the core
(i.e., writing to HIKDO or HIMDO registers). The bit is cleared by a host processor read from the
keyboard/mouse channel output buffer (6016).
1IBF (Input Buffer Full). The bit is set when the keyboard/mouse channel’s DBBIN is written to the host
processor (i.e., writing to either address 6016, data or address 6416, control). The bit is cleared when the core
reads the input buffer (HIKMDI).
2F0 (Flag 0). A general-purpose flag that can be set or cleared by the core firmware.
3A2 (A2 Address). Holds the value of the A2 signal in the last write operation of the host to the keyboard/mouse
channel’s input buffer (i.e., A2=0 for Data In Buffer write and A2=1 for Command In Buffer write).
7-4 ST3-ST0 (Status). Four general-purpose flags that can be set or cleared by the core firmware.
Bit 76543210
Name Keyboard/Mouse DBBIN Data
Bit Description
7-0 Keyboard/Mouse DBBIN Data.
Bit 76543210
Name Keyboard/Mouse DBBIN Data
Bit Description
7-0 Keyboard/Mouse DBBIN Data.
5.0 Host Controller Interface Modules (Continued)
www.national.com 282 Revision1.07
PC87591E/S/L
5.1.4 Core Interface Registers
Some register bits affect PM channel 1 to achieve firmware compatibility with the PC87570.
For a summary of the abbreviations used for Register Type, see Section 2 on page 34.
Core Interface Register Map
Host Interface Control Register (HICTRL)
The HICTRL is used in setting host interface mechanism options. On reset, non-reserved bits of HICTRL are cleared.
Location: 00 FEA016
Type: R/W
Mnemonic Register Name Type
HICTRL Host Interface Control R/W
HIIRQC Host Interface IRQ Control R/W
HIKMST Host Interface Keyboard/Mouse Status R/W
HIKDO Host Interface Keyboard Data Out Buffer WO
HIMDO Host Interface Mouse Data Out Buffer WO
HIKMDI Host Interface Keyboard/Mouse Data In Buffer RO
Bit 76543210
Name Reserved PMICIE PMIOCIE PMIHIE IBFCIE OBECIE OBFMIE OBFKIE
Reset 00000000
Bit Description
0OBFKIE (Output Buffer Full Keyboard Interrupt Enable).
0: IRQ1 is controlled by IRQ1B bit in HIIRQC register
1: Enables the Output Buffer Full interrupt to the keyboard driver of the host processor (IRQ1). The interrupt is
triggered by a core write to HIKDO register and sent according to IRQM field and IRQNPOL bit in HIIRQC reg-
ister.
1OBFMIE (Output Buffer Full Mouse Interrupt Enable).
0: IRQ12 is controlled by IRQ12B bit in HIIRQC register
1: Enables the Output Buffer Full interrupt to the mouse driver in the host processor (IRQ12). The interrupt is trig-
gered by the core write to HIMDO register and sent according to IRQM field and IRQNPOL bit in HIIRQC reg-
ister.
2OBECIE (Output Buffer Empty Core Interrupt Enable).
0: Interrupt signal is low
1: Enables the Output Buffer Empty interrupt to the core ICU for the keyboard/mouse channel. The interrupt signal
is active when the output buffer is empty (i.e., the interrupt signal is set (1) when OBF bit is cleared).
3IBFCIE (Input Buffer Full Core Interrupt Enable).
0: Interrupt signal is low
1: Enables the Input Buffer Full interrupt to the core ICU for the keyboard/mouse channel. The interrupt signal is
active when the input buffer is full (i.e., the interrupt signal is set (1) when IBF bit is set).
4PMIHIE (PMI Channel 1 Host Interrupt Enable).
0: IRQ11 is controlled by IRQ11B bit in HIIRQC register
1: Enables the Output Buffer Full interrupt of PM channel 1 in PC87570 Compatible mode, to drive the host pro-
cessor interrupt. The interrupt is noted as IRQ11 and may be routed to any of the IRQs, to SMI or to the SCI
events. The interrupt is triggered by a core write to HIPM0DO register and sent according to IRQM field and
IRQNPOL bit in HIIRQC register.
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 283 www.national.com
PC87591E/S/L
Host Interface IRQ Control Register (HIIRQC)
The HIIRQC register controls the IRQ signals mode of operation. On reset, HIIRQC is set to 0716.
Location: 00 FEA216
Type: R/W
5PMOCIE (PM Channel 1 Output Buffer Empty Core Interrupt Enable).
0: Interrupt signal is low
1: Enables the PM Output Buffer Empty interrupt to the core ICU for PM channel 1 in PC87570 Compatible mode.
The interrupt signal is active when the output buffer is empty (OBF bit is cleared in the PM channel status reg-
ister).
6PMICIE (PM Channel 1 Input Buffer Full Core Interrupt Enable).
0: Interrupt signal is low
1: Enables the PM input buffer full interrupt to the core ICU for PM channel 1 in PC87570 Compatible mode. The
interrupt signal is active when the input buffer is full (IBF bit is set in the PM channel status register).
7Reserved.
Bit 76543210
Name Reserved IRQNPOL IRQM IRQ11B IRQ12B IRQ1B
Reset 00000111
Bit Description
0IRQ1B (Host Interrupt Request 1 Control Bit). When the IRQ1 signal is configured for direct control by the
firmware (OBFKIE in HICTRL register is 0), IRQ1B bit is output to the IRQ1 signal. When read, IRQ1B bit
returns the current value of the IRQ1 pin. The IRQ1 signal value an be read regardless of the state of OBFKIE
bit.
1IRQ12B (Host Interrupt Request 12 Control Bit). When the IRQ12 signal is configured for direct control by the
firmware (OBFMIE in HICTRL register is 0), IRQ12B bit is output to the IRQ12 signal. When read, IRQ12B bit
returns the current value of the IRQ12 pin. The IRQ12 signal value can be read regardless of the state of the
OBFMIE bit.
2IRQ11B (Host Interrupt Request 11 Control Bit). When PM channel 1 is in PC87570 Compatible mode and
its host interrupt is configured for direct control by the firmware (PMHIE in HICTRL register is 0), IRQ11B bit is
output to the IRQ11 signal. When read, IRQ11B bit returns the current value of the IRQ11 signal. The IRQ11
signal value can be read regardless of the state of PMHIE bit; see Section 5.2 on page 285 for details about the
PM channel 1 interrupt scheme.
5-3 IRQM (IRQ Mode). Sets the hardware-controlled IRQ signals to work in Level or Pulse mode and defines the
pulse width in Pulse mode.
When IRQM = 0002, the IRQ signals function in Level mode. In this mode, when IRQNPOL = 0, the signal’s
default value is low, and a high level is set to issue an interrupt (the respective OBF is set).
When IRQM 0, the host interrupts are in Pulse mode. When IRQNPOL = 0, the signal’s default value is high
and toggles low to issue an interrupt (i.e., when the respective output buffer register is written). The pulse width
is as follows:
Bits
5 4 3 Pulse Width
0 0 0: Level Interrupt
0 0 1: 1-Cycle Pulse
0 1 0: 2-Cycle Pulse
0 1 1: 4-Cycle Pulse
1 0 0: 8-Cycle Pulse
1 0 1: 16-Cycle Pulse
Other: Reserved
Bit Description
5.0 Host Controller Interface Modules (Continued)
www.national.com 284 Revision1.07
PC87591E/S/L
Host Interface Keyboard/Mouse Status Register (HIKMST)
The HIKMST register provides the status of the Host Interface keyboard channel buffers (DBBIN and DBBOUT) and a way
for the PC87591x to send status bits to the host. This register can also be read by a host processor read operation from
address 6416. On reset, the register is cleared.
Location: 00 FEA416
Type: R/W
Host Interface Keyboard Data Out Buffer Register (HIKDO)
The HIKDO register allows the core firmware to write to DBBOUT register while setting OBF bit in the Status register. If IRQ1
interrupt is enabled, it is sent. If the core interrupt on output buffer empty is enabled (OBECIE in HICTRL register is 1), writing
to HIKDO de-asserts it (low).
Location: 00 FEA616
Type: WO
6IRQNPOL (Negative Polarity). When IRQNPOL is cleared, the IRQ (IRQ1, IRQ11, IRQ12) signal polarity is
compatible with the standard ISA bus interface (as specified in the IRQM field). When hardware IRQ generation
is enabled (HICTRL register bits OBFKIE for IRQ1 and IRQ12; PMHIE for IRQ11), the interrupt output is
inverted if IRQNPOL is set.
7Reserved.
Bit 76543210
Name ST3-ST0 A2 F0 IBF OBF
Reset 0 0000
Bit Description
0OBF (Output Buffer Full). The bit is set when the keyboard/mouse channel’s DBBOUT is written by the core
(i.e., writing to HIKDO or HIMDO register). The bit is cleared by a host processor read from the keyboard/mouse
channel output buffer (6016). This read-only bit is ignored when writing to this register.
1IBF (Input Buffer Full). The bit is set when the keyboard/mouse channel’s DBBIN is written by the host
processor, i.e., writing to either address 6016 (data) or address 6416 (control). The bit is cleared by a core read
of the input buffer (HIKMDI). This read-only bit is ignored when writing to this register.
2F0 (Flag 0). A general-purpose flag that can be set or cleared by the core firmware.
3A2 (A2 Address). Holds the value of the A2 signal in the last write operation of the host to the keyboard/mouse
channel’s input buffer (i.e., indicates A2 value during write to address 6016 or 6416). This read-only bit is ignored
when writing to this register.
7-4 ST3-ST0 (Status Bits). Four general-purpose flags that can be set or cleared by the core firmware.
Bit 76543210
Name Keyboard DBBOUT Data
Bit Description
7-0 Keyboard DBBOUT Data.
Bit Description
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 285 www.national.com
PC87591E/S/L
Host Interface Mouse Data Out Buffer Register (HIMDO)
The HIMDO register allows the core firmware to write to the DBBOUT register while setting OBF bit in the Status register. If
an IRQ12 interrupt is enabled, it is sent. If the core interrupt on output buffer empty is enabled (OBECIE in HICTRL register
is 1), writing to HIMDO de-asserts it (low).
Location: 00 FEA816
Type: WO
Host Interface Keyboard/Mouse Data In Buffer Register (HIKMDI)
The HIKMDI register allows the core firmware to read to the DBBIN register while clearing IBF bit in the Status register. If
the core interrupt on IBF is enabled (IBFCIE in HICTRL register is 1). Reading from HIKMDI de-asserts it (low).
Location: 00 FEAA16
Type: RO
5.2 POWER MANAGEMENT (PM) CHANNELS
The PC87591x implements two PM communication channels, both of which are compliant with ACPI specifications for an
embedded controller interface. The PC87591x may be configured to work in either Private Interface or Shared Interface
mode. The PM interface has two identical channels, which are individually configured and used. If using only one channel,
Shared Interface mode should be used; if using both channels, Private Interface mode may be used.
The description below refers to a single channel. The signals may have the suffix ‘n’ to indicate the channel number, either
1 or 2, where applicable. Registers in the core domain have the prefix HIPMn to indicate the channel number. Host domain
registers are identified by the logical device to which they belong.
Note: When working in PC87570 Compatible mode, only channel 1 may be used.
5.2.1 Features
Two operation modes
PC87570 Compatible
Enhanced PM
ACPI embedded controller interface compliant support
Shared interface
Private interface
PM channel registers (legacy 6216,66
16)
Command/Status
Data
PM interrupt using
IRQ
SMI
SCI
Bit 76543210
Name Mouse DBBOUT Data
Bit Description
7-0 Mouse DBBOUT Data.
Bit 76543210
Name Keyboard/Mouse DBBIN Data
Bit Description
7-0 Keyboard/Mouse DBBIN Data.
5.0 Host Controller Interface Modules (Continued)
www.national.com 286 Revision1.07
PC87591E/S/L
5.2.2 General Description
The PM channel has two modes of operation:
PC87570 Compatible (available for channel 1 only) supports software previously written for the PC87570.
Enhanced PM includes a mechanism that facilitates easier generation of SCI and SMI interrupts to the host.
Figure 95 is a schematic diagram of the PM channel.
Data Registers
The PM channel has three registers.
DBBOUT - can be written to by the core and read by the host processor. Multiple addresses in the core address
space enable generating an IRQ, SMI or SCI interrupt on Output Buffer Full (OBF).
DBBIN - can be written to by the host processor and read by the core.
STATUS - can be read by both the core and the host processor. It has five bits (bits 2 and 4-7) that are written to by
the core directly or, in Enhanced PM mode, via the control and configuration register. Three other bits are controlled
by hardware to indicate the status of DBBIN and DBBOUT registers.
Host Addresses
The host processor accesses the PC87591x PM channel interface registers at two addresses in the host address space.
These addresses are defined by two internal chip select signals specified in the PC87591x Host configuration registers; see
Section 6.1.13 on page 355 and Section 6.1.14 for channels 1 and 2, respectively. Legacy setting of these addresses is 6216
and 6616 for channel 1 Status/Command and Data registers, respectively.
Table 43 shows the register mapping to the host processor I/O space. For simplicity, the Host Interface module specification
refers to the legacy addresses.
DBBIN
DBBOUT
Status
D0-7
D0-7
IRQ
Peripheral Bus
SIB Bus
Input Buffer
Full
Output Buffer
Empty
Interrupts to the Core
Interrupt to the Host Processor
Host-WR-Data Buffer
Host-RD-Data-Buffer
Figure 95. Host Interface PM Channel n Block Diagram
SMI SCI
Command/Status
or Data
WR-PM RD-PM
Buffer
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 287 www.national.com
PC87591E/S/L
Table 43. Host Interface Registers to Host Processor Mapping
Core Interrupts
For each channel, the Host Interface module generates two level (high) interrupts to the core ICU (see Figure 96). The firm-
ware can use these for interrupt-driven control of the PM channels.
In PC87570 Compatible mode (EME in HIPMnCTL register is set to 0), interrupts are enabled using HICTRL register bits
PMOCIE and PMICIE for output buffer empty and input buffer full interrupts, respectively.
In Enhanced PM mode (EME in HIPMnCTL register is set to1), interrupts are enabled using HIPMnCTL register bits OBEIE
and IBFIE for output buffer empty and input buffer full interrupts, respectively.
Host Interrupt Generation Modes
The Host Interface module generates three types of interrupts to the host: regular IRQ, SMI and SCI. The interrupt schemes
are designed to meet ACPI requirements for host interrupts. Two interrupt modes are supported: PC87570 Compatible and
Enhanced PM.
PC87570 Compatible Mode
PC87570 Compatible mode uses the same method for IRQ generation as the PC87570. It is available only for PM channel 1
and is enabled when EME in HIPMnCTL register is set to 0. Figure 98 illustrates this scheme.
The host configuration module assigns host interrupts to IRQ numbers (see Section 6.1.13 on page 355). IRQ11 is used as
an example interrupt and for the signal naming (the actual interrupt number used is determined by the IRQ routing logic).
When hardware-driven IRQ11 is disabled (PMHIE in HICTRL register is cleared), the firmware can control the IRQ11 signal
by writing to the signal’s respective bit in HIIRQC register. When hardware-driven IRQ11 is enabled (PMHIE is set to 1),
interrupts to the host are generated according to the status of the OBF flag.
Port Legacy
Address1
1. The legacy address serves as an example only. Do not assign the same address for both channels.
Configuration
Register Index PM Internal Chip
Select Type Register
Name Mnemonic
PM
Channel n 6216 Index 6016,61
16 Data Write Data DBBIN
6616 Index 6216,63
16 Command/Status Write Command DBBIN
6216 Index 6016,61
16 Data Read Data DBBOUT
6616 Index 6216,63
16 Command/Status Read Status STATUS
IBF bit (HIPMnST)
1
0
EME bit (HIPMnCTL)
OBF bit (HIPMnST)
PMOCIE bit (HICTRL)
OBEIE bit (HIPMnCTL)
1
0
PMICIE bit (HICTRL)
IBFIE bit (HIPMnCTL)
PMnOBE
Interrupt
PMnIBF
Interrupt
ICU
Figure 96. Core Interrupt Request for PM Channel n
EME bit (HIPMnCTL)
5.0 Host Controller Interface Modules (Continued)
www.national.com 288 Revision1.07
PC87591E/S/L
In Normal Polarity mode (IRQNPOL in HIIRQC register is cleared), the PC87591x supports two types of interrupts: legacy
edge or legacy level. When an edge interrupt is selected (IRQM field in HIIRQC register is set to a value other than 0), the
interrupt signal default value is high (1). When an interrupt signal must be sent (i.e., OBF flag is set), a negative pulse is
generated. The pulse width is determined by the same field, IRQM, that selects the edge interrupt.
When a level interrupt is selected (IRQM in HIIRQC register is cleared), the interrupt signal is usually low (0). It is asserted
(1) to indicate that the respective OBF flag has been set. The signal is de-asserted (0) when the output buffer is read (i.e.,
OBF flag is cleared).
In Negative Polarity mode (IRQNPOL in HIIRQC register is set to 1), IRQ signal behavior is inverted from the behavior de-
scribed for normal polarity.
The PC87591x firmware can read the value of the IRQ11 signal by performing a read operation of IRQ11B bit in HIIRQC
register.
The core can also control the routing of interrupts generated by the PM channel to one of the following:
IRQ signal, when IRQE bit in HIPMnIE register is set
SMI output, when SMIE bit in HIPMnIE register is set
SCI event, using the SCIEC output, when SCIE bit in HIPMnIE register is set.
The core firmware should not enable more than one of these interrupts simultaneously. It should also update ST0 and ST1
bits to indicate the type of host interrupt used.
Enhanced PM Mode
Enhanced PM mode is available for both PM channels. It is enabled when EME in HIPMnCTL register is set to 1. Figure 98
illustrates interrupt generation in this mode.
Either IRQ, SMI or SCI interrupts may be generated under software control or by using hardware. Using hardware reduces
software overhead and simplifies procedures.
The mechanism that generates the IRQ is identical to that used in PC87570 Compatible mode. To enable identical control
of both channels, the bits that are used for channel 1 are separated from the keyboard/mouse channel’s registers; see
Figure 98 for bit usage.
IRQE in HIPMnIE register determines if an IRQ is sent from PM Channel n.
Enhanced PM mode supports direct generation of SCI and SMI on core writes to the Data output buffer and generation of
SCI on core reading of the Data Input buffer. The core decides whether to generate an interrupt and which type of interrupt
to generate by selecting the data register address in use.
When data is written to HIPMnDO register, the OBF flag in HIPMnST register is set and neither SMI nor SCI is generated.
Hardware
IRQM field (HIIRQ)
Interrupt
IRQNPOL bit (HIIRQC)
1
0
IRQ11B bit (HIIRQC)
PMHIE bit (HICTRL)
1
0
IRQ11B bit (HIIRQC)
IRQ11B bit (HIIRQC)
(Part of SuperI/O
Configuration
Module)
IRQ Routing
and Polarity
IRQ
Serializer
IRQE bit (HIPMnIE)
SMIE bit (HIPMnIE)
SCIE bit (HIPMnIE)
Gathering
SMI Source
Gathering
SCI Source
SMI
ECSCI
Figure 97. IRQ, SCI and SMI Control in PC87570 Compatible Mode (PM Channel 1 Only)
OBF
0
1
0
1
SMIPOL bit (HIPMnIC)
SCIPOL bit (HIPMnCTL)
(write)
(read)
(Level or Edge) (Polarity)
(Hardware or Firmware)
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 289 www.national.com
PC87591E/S/L
When data is written to HIPMnDOM register, the OBF flag and the internal OBF_SMI flag are set and an SMI interrupt is
generated. The OBF_SMI flag is cleared when OBF flag is cleared. The SMI is generated as a pulse whose width is defined
by PLMM in HPIMnIC register.
The SMI interrupt is routed to the SMI pin only if both HSMIE and SMIE bits in HIPMnIE register are set. When SMIE is set
and HSMIE is cleared, SMIB in HIPMnIC register is used as the PMnSMI signal value. When SMIE is cleared, the PMnSMI
signal is inactive (high).
When data is written to HIPMnDOC register, the OBF flag and OBF_SCI internal flag are set and an SCI interrupt is gener-
ated. OBF_SCI is cleared when OBF is cleared. The SCI is generated as a pulse whose width is defined by PLMS in
HPIMnCTL register.
When data is read from HIPMnDIC register, the IBF flag is cleared, the IBF_SCI Internal flag is set and an SCI interrupt is
generated. The IBF_SCI flag is cleared when the IBF is set again. The SCI is generated as a pulse whose width is defined
by PLMS in HPIMnCTL register. Reading from HIPnDI register clears the IBF flag but does not generate an SCI interrupt.
Note that IBF_SCI flag may also be set by writing a 1 to SCIIS bit in HIPMnIC register. This is done to start an SCI interrupt
on input buffer empty without a read operation from the input buffer.
The SCI interrupt is routed to the SCI pin only if HSCIE and SCIE in HIPMnIE register are set. When SCIE is set and HSCIE
is cleared, the value of SCIB in HIPMnIC register is used as the PMnSCI signal value. When SCIE is cleared, PMnSCI is
inactive (high).
Status Read
The status of the PM channel data buffers can be read by both the host and the core. Bits 2 and 4-7 can be written by the core.
The host processor should read the Status register I/O address (legacy 6616, for channel 1) to obtain the contents of the Status
register. The core software should read/write the HIPMnST register to access the same information. The format of the Status
register is identical for both the host and the core; see “Host Interface PM n Status Register (HIPMnST)” on page 291.
Hardware
IRQM field (HIIRQC)
Interrupt
IRQNPOL bit (HIIRQC)
1
0
IRQB bit (HIPMnIC)
1
0
IRQB bit (HIPMnIC)
(Part of
Module)
IRQ
and
IRQE bit (HIPMnIE)
SMIE bit (HIPMnIE)
Gathering
SMI
OBF bit
SuperI/O
Config
Routing
Polarity
IRQ
Serializer
IRQB bit (HIPMnIC)
HIPMnDOM (write)
HIPMnDI (read)
HIPMnDO (write)
HIPMnDIC (read)
set OBF_no_int
set OBF_SMI
HIPMnDOC (write) set OBF_SCI
clear IBF bit (HIPMnST)
1
0
1
0
SMIB bit (HIPMnIC)
SCIB bit (HIPMnIC)
Pulse Shape
Figure 98. IRQ, SCI and SMI Control, Enhanced PM Mode
PLMM field (HIPMnIC)
PLMS field (HIPMnCTL)
HSMIE bit (HIPMnIE)
HSCIE bit (HIPMnIE)
HIRQE bit (HIPMnIE)
PMnSMI
Pulse Shape
0
1
0
1
Source
ECSCI
set IBF_SCI
SCIIS bit (HPMnIC)
(write 1)
SMIPOL bit (HIPMnIC)
SCIPOL bit (HIPMnCTL)
SCIE bit
PMnECSCI of
other channel
PMnECSCI
SCIB bit (HIPMnIC) (read)
SMIB bit (HIPMnIC)
(write)
(read)
(HIPMnIE)
(HIPMnST)
(read)
5.0 Host Controller Interface Modules (Continued)
www.national.com 290 Revision1.07
PC87591E/S/L
Host Data Write to Host PM Channel
The data buffer has two latches: one serves as an input buffer and the other serves as an output buffer. When writing to the
Command (legacy address 6616) or Data (legacy address 6216) registers, the following sequence occurs: data is written to
the Data In latch (DBBIN), IBF bit in the Status register is set and bit 3 (A2) in the Status register indicates to the core which
of the two addresses was written to. When writing to the data register address, A2 bit of the Status register is cleared (0).
When writing to the Command register address, A2 bit in the Status register is set (1).
The core identifies that data is present in the input buffer by either polling IBF bit in the Status register or acknowledging an
interrupt when the input buffer interrupt is enabled (IBFCIE bit in HICTRL register is set to 1).
When the input buffer is full, the Status register should be read to identify which addresses were written to by checking A2
bit in HIPMnST register. The core can then read the data from the input buffer (HIPMnDI or HIPMnDIC registers). The IBF
status bit is cleared when the data input buffer is read by the core.
Host Data Read from Host Interface Power Management Channel
The core writes to the Output Data latch (DBBOUT) when it needs to send data to the host. The OBF flag in the Status reg-
ister (HIPMnST) is set to indicate that data is available in DBBOUT. DBBOUT should be written to only when OBF in
HIPMnST register is cleared.
The PC87591x supports polling and interrupt communication schemes with the host. IRQ, SMI or SCI interrupts may be
used. The core firmware writes data addressed to the PM drivers to the HIPMnDO register. When working in Enhanced PM
mode, writes to HIPMnDOC and HIPMnDOM may be used to automatically generate SCI and SMI, respectively. Refer to
“Host Interrupt Generation Modes” on page 287 for details of the interrupt generation scheme.
The host processor identifies the presence of data in the output buffer by either polling the Status register or by responding
to IRQ, SMI or SCI events. When such data is available, the host can read it using a read operation from the address of the
data register (legacy 6216 for channel 1). Reading from the data register clears the OBF flag (HIPMnST). In addition, when
the host interrupt is in level mode (IRQM in HIIRQC register is set to 0002) and the hardware interrupt is enabled, the IRQ
signal is de-asserted (low).
The core can read OBF in HIPMnST register to identify when the output buffer is empty and ready for a new data transfer.
When the output buffer empty interrupt to the core is enabled (PMOCIE bit in HICTRL register is 1 when EME bit in HIP-
MnCTL register is 0), the interrupt signal to the ICU is set high if the output buffer is empty (OBF is set to 0).
5.2.3 Core PM Registers
For a summary of the abbreviations used for Register Type, see Section 2 on page 34.
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 291 www.national.com
PC87591E/S/L
Core PM Register Map
Host Interface PM n Status Register (HIPMnST)
The HIPMnST register contains the status of the host interface PM channel buffers (DBBIN and DBBOUT). It also provides
a means for the PC87591x to send status bits to the host. This register is read by a host processor read operation from ad-
dress 6616. HIPMnST is cleared on reset.
Location: Channel 1 - 00 FEAC16
Channel 2 - 00 FEBE16
Type: Varies per bit
Mnemonic Register Name Type
HIPMnST1
1. Where n stands for register 1 or 2.
Host Interface PM n Status Varies per bit
HIPMnDO1Host Interface PM n Data Out Buffer WO
HIPMnDOC1Host Interface PM n Data Out Buffer with SCI WO
HIPMnDOM1Host Interface PM n Data Out Buffer with SMI WO
HIPMnDI1Host Interface PM n Data In Buffer RO
HIPMnDIC1Host Interface PM n Data In Buffer with SCI RO
HIPMnCTL1Host Interface PM n Control R/W
HIPMnIC1Host Interface PM n Interrupt Control R/W
HIPMnIE1Host Interface PM n Interrupt Enable R/W
Bit 76543210
Name ST3-ST0 A2 F0 IBF OBF
Reset 00000000
Bit Type Description
0ROOBF (Output Buffer Full). The bit is set when the PM channel’s DBBOUT is written to by the core
(writing to HIPMnDO, HIPMnDOM or HIPMnDOC register). The bit is cleared by a host processor read
of the output buffer (6216). Writing to this bit is ignored.
1ROIBF (Input Buffer Full). The bit is set when the PM channel’s DBBIN is written to by the host
processor (writing to either address 6216 or address 6616). The bit is cleared by a core read of the PM
input buffer (HIPMnDI or HIPMnDIC).
2 R/W F0 (Flag 0). General-purpose flag that can be set or cleared by the core firmware.
3ROA2 (A2 Address). Indicates whether the last write operation of the host to the PMn channel was to the
data register or the Command register. Writing to this bit is ignored.
0: Last write was to the data register (pointed to by configuration register index 6016 and 6116)
1: Last write was to the command register (pointed to by configuration register index 6216 and 6316)
7-4 R/W ST3-ST0 (Status). Four general-purpose flags that can be used for signaling between the host and
core. When used as an embedded controller interface channel for ACPI, a predefined meaning is
assigned to ST0, ST1 and ST2. The standard meaning is BURST, SCI event and SMI event,
respectively.
5.0 Host Controller Interface Modules (Continued)
www.national.com 292 Revision1.07
PC87591E/S/L
Host Interface PM n Data Out Buffer (HIPMnDO)
The HIPMnDO register allows the core firmware to write to the PM port DBBOUT register while setting the PM port OBF bit
in the Status register. If enabled, an IRQ11 (and/or SCI and/or SMI, in PC87570 Compatible mode) interrupt is sent at that
time. If the core interrupt on PM port output buffer empty is enabled, writing to HIPMnDO de-asserts it (low). If DMA on output
buffer empty is enabled, the DMA request is de-asserted on the write to HIPMnDO.
Location: Channel 1 - 00 FEAE16
Channel 2 - 00 FEC016
Type: WO
Host Interface PM n Data Out Buffer with SCI (HIPMnDOC)
The HIPMnDOC register has the same function as the HIPMnDO register. In addition, it generates an SCI interrupt when
OBF is set and hardware SCI generation is enabled.
Location: Channel 1 - 00 FEB216
Channel 2 - 00 FEC416
Type: WO
Host Interface PM n Data Out Buffer with SMI (HIPMnDOM)
The HIPMnDOM register has the same function as the HIPMnDO register. In addition, it generates an SMI interrupt when
OBF is set and hardware SMI generation is enabled.
Location: Channel 1 - 00 FEB416
Channel 2 - 00 FEC616
Type: WO
Bit 76543210
Name PM Channel DBBOUT Data
Bit Description
7-0 PM Channel DBBOUT Data.
Bit 76543210
Name PM Channel DBBOUT Data
Bit Description
7-0 PM Channel DBBOUT Data.
Bit 76543210
Name PM Channel DBBOUT Data
Bit Description
7-0 PM Channel DBBOUT Data.
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 293 www.national.com
PC87591E/S/L
Host Interface PM n Data In Buffer (HIPMnDI)
The HIPMnDI register allows the core firmware to read the PM port DBBIN register while clearing the PM port IBF bit in the
Status register. If the core interrupt on IBF for the PM channel is enabled, reading from HIPMnDI de-asserts it (low).
Location: Channel 1 - 00 FEB016
Channel 2 - 00 FED216
Type: RO
Host Interface PM n Data In Buffer with SCI (HIPMnDIC)
The HIPMnDIC has the same function as the HIPMnDI register. In addition, it generates an SCI interrupt when IBF is cleared
and when hardware SCI generation is enabled.
Location: Channel 1 - 00 FEB616
Channel 2 - 00 FEC816
Type: RO
Bit 76543210
Name PM Channel DBBIN Data
Bit Description
7-0 PM Channel DBBIN Data.
Bit 76543210
Name PM Channel DBBIN Data
Bit Description
7-0 PM Channel DBBIN Data.
5.0 Host Controller Interface Modules (Continued)
www.national.com 294 Revision1.07
PC87591E/S/L
Host Interface PM n Control Register (HIPMnCTL)
The HIPMnCTL register controls the operation mode and configuration of the PM channel. It includes the Enhanced mode
enable bit and control bits for Enhanced mode operation. HIPMnCTL is 4016 on reset.
Location: Channel 1 - 00 FEB816
Channel 2 - 00 FECA16
Type: R/W
Bit 76543210
Name EME SCIPOL PLMS Reserved OBEIE IBFIE
Reset see text 1000000
Bit Description
0IBFIE (Input Buffer Full Interrupt Enabler).
0: IBF interrupt to the core is disabled
1: Enables an interrupt to the core when IBF in HIPMnST register is set
1OBEIE (Output Buffer Empty Interrupt Enable).
0: OBF interrupt to the core is disabled
1: Enables an interrupt to the core when OBF in HIPMnST register is set
2Reserved.
5-3 PLMS (Pulse Level Mode SCI). Sets the hardware-controlled SCI signal mode to be Level or Pulse and sets
the pulse width.
When PLMS = 0002, the SCI signal functions in Level mode. In this mode, the SCI pulse shaper output value is
low, and a high level is set to issue an interrupt (the respective OBF is set).
When PLMS 0, the host interrupts are in Pulse mode. In this mode, the SCI pulse shaper output value is low,
and it toggles high to issue an interrupt (i.e., when the respective output buffer register is written).
The pulse widths are:
Bits
5 4 3 Pulse Width
0 0 0: Level interrupt
0 0 1: 1-Cycle Pulse
0 1 0: 2-Cycle Pulse
0 1 1: 4-Cycle Pulse
1 0 0: 8-Cycle Pulse
1 0 1: 16-Cycle Pulse
Other: Reserved
6SCIPOL (SCI Negative Polarity).
0: SCI output inactive value is low and its active (asserted) value is high
1: Inverted polarity is used. When SCIPOL is set, the SCI signal is the inverse of either what is stored in SCIB or
the output of the SCI pulse shaper.
This bit affects the SCI signal polarity in both PC87570 Legacy and Enhanced modes.
7EME (Enhanced Mode Enable).
0: PM channel is used in Legacy mode. HIPMnST status bits are controlled by writes to the bit value, and inter-
rupts are controlled by HICTRL and HIIRQC register bits (default for HIPM1CTL).
1: Enables enhanced control of the PM channel. The bits in HICTRL and HIIRQC registers are ignored in this case
(default for HIPM2CTL).
In HIPM2CTL (i.e., for PM channel 2), EME is a read-only bit that holds the value 1. Writes to this bit are
ignored.
5.0 Host Controller Interface Modules (Continued)
Revision 1.07 295 www.national.com
PC87591E/S/L
Host Interface PM n Interrupt Control Register (HIPMnIC)
The HIPMnIC register and its bits affect operation in Enhanced mode only (i.e., when EME bit in HIPMnCTL register is set).
In PC87570 Legacy mode, the bits in this registers are ignored. HIPMnIC controls the PM n interrupt signals mode of oper-
ation. HIPMnCTL is 4116 on reset.
Location: Channel 1 - 00 FEBA16
Channel 2 - 00 FECC16
Type: R/W
Bit 76543210
Name SCIIS SMIPOL PLMM SCIB SMIB IRQB
Reset 01000001
Bit Description
0IRQB (Host Interrupt Request Control Bit). When the IRQ signal is configured for direct control by the
firmware (HIRQE in HIPMnIE register is 0), IRQB bit is output to the PMnIRQ signal. When read, IRQB bit
returns the current value of the PMnIRQ signal. IRQn signal’s value can be read regardless of the state of
HIRQE in HIPMnIE register.
1SMIB (Host SMI Request Control Bit). When the SMI signal is configured for direct control by the firmware
(HSMIE in HIPMnIE register is 0), SMIB bit is output to the PMnSMI signal (if SMIPOL=0, SMIB is output; if
SMIPOL=1, SMIB is inverted before output). When read, SMIB bit returns the current value of the SMI pin. The
SMI signal’s value can be read regardless of the state of HSMIE in HIPMnIE register.
2SCIB (Host SCI Request Control Bit). When the SCI signal is configured for direct control by the firmware
(HSCIE in HIPMnIE register is 0), SMIB bit is output to the PMnSCI signal (if SCIPOL=0, SCIB is output; if
SCIPOL=1, SCIB is inverted before output). When read, SCIB bit returns the current value of the SCI pin. The
ECSCI signal value can be read regardless of the state of HSCIE bit in HIPMnIE register.
5-3 PLMM (Pulse Level Mode SMI). Sets the hardware-controlled SMI signal mode to Level or Pulse and sets the
pulse width.
When PLMM = 0002, the SCI signal functions in Level mode. In this mode, the SMI pulse shaper output value is
low, and a high level is set to issue an interrupt (i.e., the respective OBF is set).
When PLMM 0, the host interrupts are in Pulse mode. In this mode, the SMI pulse shaper output value is low,
and it toggles high to issue an interrupt (i.e., when the respective output buffer register is written).
The pulse widths are:
Bits
5 4 3 Pulse Width
0 0 0: Level interrupt
0 0 1: 1-Cycle Pulse
0 1 0: 2-Cycle Pulse
0 1 1: 4-Cycle Pulse
1 0 0: 8-Cycle Pulse
1 0 1: 16-Cycle Pulse
Other: Reserved
6SMIPOL (SMI Negative Polarity).
0: SMI output inactive value is low and its active (asserted) value is high
1: Inverted polarity is used. When SMIPOL is set, the SMI signal is either the inverse of what is stored in SMIB or
the output of the SMI pulse shaper.
This bit affects the SMI signal polarity in both PC87570 Legacy and Enhanced modes
7SCIIS (SIC on IBF Start). A write of 1 to this bit starts an SCI interrupt on IBF cleared. A write of 0 to SCIIS is
ignored. When read, this bit always return 0.
5.0 Host Controller Interface Modules (Continued)
www.national.com 296 Revision1.07
PC87591E/S/L
Host Interface PM n Interrupt Enable Register (HIPMnIE)
The HIPMnIE register controls the PM n interrupt signals that enable SMI, SCI and IRQ interrupts. HIPMnIE is cleared on reset.
Location: Channel 1 - 00 FEBC16
Channel 2 - 00 FECE16
Type: R/W
Bit 76543210
Name Reserved HSMIE HSCIE HIRQE SMIE SCIE IRQE
Reset 00000000
Bit Description
0IRQE (IRQ Enable).
0: PMnIRQ signal assumes its default value (low) and no interrupts are issued
1: Enables PM generation of IRQ events
1SCIE (SCI Enable).
0: PMnSCI signal assumes its default value (high) and no interrupts are issued
1: Enables PM generation of SCI events
2SMIE (SMI Enable).
0: PMnSMI signal assumes its default value (high) and no interrupts are issued
1: Enables the generation of SMI events by this module
3HIRQE (Hardware IRQ Enable). Works only in Enhanced PM mode.
0: IRQB bit of HIPMnIC register controls the value of the IRQ
1: Enables the generation of IRQ events by hardware control based on the status of the OBF flag
4HSCIE (Hardware SCI Enable). Works only in Enhanced PM mode.
0: SCIB bit in HIPMnIC register controls the value of the SCI
1: Enables the generation of SCI events by hardware control based on the status of the OBF and IBF flags
5HSMIE (Hardware SMI Enable). Works only in Enhanced PM mode.
0: SMIB bit in HIPMnIC register controls the value of the SMI
1: Enables the generation of SMI events by hardware control based on the status of the OBF flag
7-6 Reserved.
Host Controller Interface Modules (Continued)
Revision 1.07 297 www.national.com
PC87591E/S/L
5.3 SHARED MEMORY AND SECURITY
The PC87591x on-chip flash can be shared by the host and the core. It may also be used by the host for BIOS code storage
or other purposes. The on-chip flash resides in the core domain. In IRE and OBD environments, it is accessible via the core
bus. For host accesses, the flash is mapped to the host memory address space via the host interface, and a bridge is pro-
vided between the host bus and the core bus. The bridge functionality includes:
Memory mapping between host domain address space and core domain address space
Host bus to core bus transaction bridging
Locking mechanism between host and core domains to maintain coherence of on-chip flash contents during updates
Read/write protection on host accesses to the on-chip flash
Host-accessible control and status registers of on-chip flash
Signaling interface for host-core communication associated with memory updates
In addition, the PC87591x supports expansion memory controlled by the core domain’s Bus Interface Unit (BIU). The bridge
also supports host accesses to the expansion memory (including read/write protection on these accesses). These accesses
can occur in IRE, OBD and DEV environments.
In the PC87591S, the Shared Memory and Security module also includes a Random Number Generator (RNG). The output
of the RNG is available to the core.
5.3.1 Host Bus to Core Bus Access Translation
A core bus transaction is generated for each of the following types of host bus transactions:
8-bit memory read/write
8-bit FWH memory read/write
8-bit indirect read/write transactions, using I/O read/write to access the shared flash (see Section 5.3.3 on page 300)
Memory and FWH memory read/write transactions drive Long Wait on the Sync field until the transaction is completed on
the core bus. Section 5.3.3 on page 300 describes the Sync field for indirect memory read/write transactions. Section 5.3.5
on page 301 describes the behavior for restricted accesses.
The host bus transaction is forwarded to the core bus after the following is done:
Address is translated
The translated address and the access type are verified to be both:
In core domain’s base memory or expansion memory spaces
Unprotected
For writes (erase/program): on-chip flash is unlocked (HLOCK bit in SMCCST register is set)
Note that host bus read transactions are translated to read transactions on the core bus, and host bus write transactions are
translated to write transactions on the core bus. Translated reads and writes behave the same as reads and writes by the
core. When the erase bit is set and the on-chip flash is enabled and addressed, the effect of a write is the same as a write
after the page erase bit is set.
5.3.2 Memory Mapping and Host Address Translation
Section 6.1.11 on page 349 describes in detail the host domain addresses for which the core bus generates transactions.
In general, the BIOS memory on the host bus can occupy one of three regions in the memory space (see Table 60 on
page 350).
Address translation between the host and the core domains is performed for host memory and FWH memory transactions.
The 32-bit address received from the host bus is used to decode the different zones, as described in Section 6.1.11 on
page 349. The address is then translated to the core bus address using the following rules:
Legacy and Extended Legacy BIOS Range
Handle only when enabled (see Section 6.1.11 on page 349 for the enabling alternatives); otherwise, transactions to
this zone are ignored. The address is converted to a shared memory internal address as follows:
SM_Host_Address[31-0] = {1111 1111 1111 111, Host_Memory_Address[16-0]}
User Defined Shared Memory Space
This address range is handled only when enabled (see Section 6.1.11 on page 349 for the enabling alternatives);
otherwise, transactions to this zone are ignored. The address translation depends on the window size defined. When
the window size is 2nbytes, the lower ‘n’ bits are taken from the memory address, and the upper 32 n bits of the
LPC address are replaced with 1. The address is converted to an internal address as follows:
SM_Host_Address[31-0] = {1111 ... ... 1, Host_Memory_Address[n-0]}
Host Controller Interface Modules (Continued)
www.national.com 298 Revision1.07
PC87591E/S/L
386 Mode-Compatible BIOS Range and User Defined Shared Memory Range
This address range is handled only when enabled (see Section 6.1.11 on page 349 for the enabling alternatives);
otherwise, transactions to this zone are ignored. The address is converted to an internal address as follows:
SM_Host_Address[31-0] = Host_Memory_Address[31-0]
Indirect Memory Address
This address specified in IMA3-0 is used as follows:
SM_Host_Address[31-0] = {IMA3[7-0], IMA2[7-0], IMA1[7-0], IMA0[7-0]}
For allowed addresses, the SM_Host_Address is translated to a core address using the following equation
(a 21-bit address in the core address space is generated by adding the host memory address to the MBTA):
CR_Space_Address[20-0] = (21 least significant bits)(SM_Host_Address + MBTA)
MBTA is the size of the PC87591x on-chip flash memory, as defined in the Shared Memory Main Block Top Address
register (SMCTA). This value is defined on reset to indicate the available memory size. In DEV environment, this value
may be changed to allow code development for other flash sizes.
The CR_Space_Address[21-0] is checked against the Host-Controlled Access Protection registers, the Core-Con-
trolled Override Protection registers and general address space access limitations (i.e., space not mapped to the
base memory or expansion memory).
Figure 99 illustrates the address translation scheme for shared memory transactions.
Access restrictions are based on the contents of the host-controlled and core-controlled access protection registers. The
access protection logic may prevent read and/or write access to addresses in the core address space. The core-controlled
register setting should always prevent host access to addresses that are not in the core domain’s base memory or expansion
memory spaces. Note that the resulting memory space is not continuous.
In DEV environment, the value of MBTA may be changed for ease of software development. The memory space between
MBTA (1 000016 in PC87591E or 2 000016 in PC87591S) to F FFFF16 is not accessible by the host.
The following figures illustrate the mapping function that results from the address translation function for a Shared BIOS
scheme (Figure 100) and when the flash is mapped as a non-BIOS block of memory (Figure 101).
FWH ID Check
Address
Translation
32
LPC
Bus
Transaction Type &
Memory Address
Decoders
MUX
32
0-16
17-31
“1”
Legacy & Extended
BIOS Range
Memory R/W
Address
MBTA
Indirect Memory Access
Reset or
IMA0-3
Core Write
Access
Protection
Logic
Access
Protection
Registers
Override
Protection
Registers
0-20
0-31
0-31
0-31
+
Core Bus
Address
Host-Controlled Core-Controlled
Figure 99. Address Translation Mechanism for 512 Kbyte On-Chip Flash
MBTA
0-20
SM_Host_Address
386 BIOS Range
0-31
0-(win_size_bits 1)
win_size_bits 31
“1” User Def. Space
Host Controller Interface Modules (Continued)
Revision 1.07 299 www.national.com
PC87591E/S/L
.
00 000016
Main Block Top Address (MBTA)
1F FFFF16
FFFF FFFF16
FFFF FFFF16 - MBTA
FFE0 000016
Expansion Memory
On-Chip Flash
10 000016
00 E00016
01 000016
1
2
FFF0 000016 - MBTA
0000 000016
000F FFFF16
1
2
Reserved (Out-of-Range)
Host Address Core Address
Legacy BIOS
Extended
Legacy BIOS
~
~~
~
1
000F 000016
000E FFFF16
000E 000016
Figure 100. Host to Core Address Translation: 386 Mode-Compatible BIOS Range
Numbers (1,2) indicate the links
between host memory and core
memory maps.
Host Controller Interface Modules (Continued)
www.national.com 300 Revision1.07
PC87591E/S/L
5.3.3 Indirect Memory Read and Write Transaction
The following I/O mapped registers can be utilized instead of memory mapping to perform a core bus transaction using an
LPC I/O transaction:
Four Indirect Memory Address registers (IMA3-IMA0), representing host address bits 31 to 0
One Indirect Memory Data register (IMD), representing data bits 7 to 0
An LPC I/O write to the IMD register triggers a core bus memory write cycle using the addresses and data from IMA3-IMA0
and IMD registers, respectively. The LPC I/O write is completed when the core bus transaction is completed.
An LPC I/O read cycle from IMD register triggers a core bus memory read cycle using the addresses from IMA3-IMA0. The
data returned from the core bus cycle is used to complete the LPC I/O read cycle from IMD register.
Read/write cycles from/to IMA3-IMA0 registers drive Short Wait on the Sync field. Read/write cycles from/to IMD register
drive Long Wait on the Sync field until a transaction is actually performed and completed on the core bus.
Indirect memory read/write transactions are subject to the same memory mapping, locking mechanism and host access pro-
tection as memory and FWH memory read/write transactions. For more details, see Sections 5.3.2, 5.3.4 and 5.3.5.
5.3.4 Locking Between Domains
For read operations, hardware handles arbitration between the host and core. For program and erase operations, the
PC87591x provides the means for enabling exclusive use for any particular access path over a sequence of operations.
By default, the core has access permission to the on-chip flash, and the HLOCK bit is cleared (0). In this case, if a program
or erase operation starts, any host read operation is deferred or aborted, as defined by HERES field in SMCCST register.
When host erase or program operation is required, the Signaling interface (Section 5.3.7 on page 303) or one of the other
host/core communication channels should be used to request control of the flash from the core. The core should go into a
state in which the flash is not written or erased and then set the HLOCK bit. Note that core reads from the flash may be
delayed in this case; therefore, it is recommended for critical code to be copied to RAM. Once the host access to the flash
is completed, the host should indicate this to the core, allowing it to clear the HLOCK bit and resume normal operation.
00 000016
Main Block Top Address (MBTA)
1F FFFF16
F FFFF16
F FFFF16 - MBTA
0 000016
10 000016
00 E00016
01 000016
1
2
0 000016 - MBTA
1
2
Host Address Core Address
~
~~
~
Figure 101. Host to Core Address Translation: Non-BIOS Mode
~
~~
~
Expansion Memory
On-Chip Flash
Reserved (Out-of-Range)
Numbers (1,2) indicate the links
between host memory and core
memory maps.
Host Controller Interface Modules (Continued)
Revision 1.07 301 www.national.com
PC87591E/S/L
The core can clear HLOCK bit at any time, preventing any further erase or program operations by the host.
5.3.5 Host Access Protection
The host read/write protection is software controlled via a set of registers accessible to the host. The protection granularity
is per block. Each of the 32 software-controlled protection blocks is 64 Kbytes; the block’s read protection and write protec-
tionflags may be set independently. A Lock Protect flag may be setto prevent future changes to the read andwrite protection
bits. Once locked, the lock bit and the read/write enable bits may be changed only after Host Domain Hardware reset.
The core can override the host settings and prevent host access to certain areas of the shared memory. The override may
be set independently for read and write. In the first 128 Kbytes of address space, each core-controlled block is 8 Kbytes. For
the rest of the memory space the blocks are 64 Kbytes each.
The default value of the protection registers is set according to the properties of the block. There are three types of blocks:
Core Boot Block:Read, Erase and Program protected from the host.
Host Boot Block:Open for Read by the host; Erase and Program protected from the host.
Other Blocks:Open for Read, Erase and Program by the host.
Core on-chip peripherals and RAM are never accessible to the host (for both read and write). The range from MBTA to
0 FFFF16 should be protected from host access using the core-controlled protection registers.
The size of any of the above blocks is defined as part of the flash protection information. This information is stored in the
flash information block at address FE16. This information is updated while the flash is programed or during a Special Erase,
through either the JTAG or Parallel Interface.See Section 4.16.6 on page 226 for information about protection information
fields.
Core Boot Block
This block is not accessible by the host and (for either read nor write). The core boot block starts at address 0 000016 and
ends as defined in the protection information field (8 Kbytes to 128 Kbytes in steps of 8 Kbytes). The core boot block access
protection settings may not be changed, and the respective protection bits are read only.
Host Boot Block
By default, this block may be read by the host. Host writes to this block are always disabled. The host boot block size is
64 Kbytes and is available when the Host Boot Block bit in the protection word is cleared. The Host boot block is always the
last 64 Kbytes of the base memory (i.e., MBTA 64 Kbytes to MBTA 1 Kbyte). In case of an overlap between the host
boot block and the core boot block, access protection settings of the core boot block are used. The host boot block access
protection settings may not be changed, and the respective protection bits are read only.
Other Blocks
By default, all other blocks are read and write protected. The core may enable host read and/or write access to these blocks.
Setting the Host Access Protection Flags
There are two sets of host access protection flags, as shown in Figure 102:
Host-controlled host access protection flags
Core-controlled host access protection flags
Host-Controlled Host Access Protection Flags. For each of the 32 protection blocks there is a set of three bits (flags):
Read Protect, Write Protect and Lock Protect. The 32 sets of flags are accessible via two registers, Shared Memory Host
Access Protect Register 1 and 2 (SMHAP1-2), using an indexing scheme.
The Host Block index may be calculated using the following equation:
Host_Block_Index = CR_Space_Address[20-0] / 64K or
Host_Block_Index = (21 least significant bits)(SM_Host_Address + MBTA) / 64K
See Section 5.3.2 on page 297 for the definitions of the host address translation.
To change a flag setting, write the new flag setting, together with the required index field (i.e., Host Access Protection
Index) and a cleared Index Write bit, to the appropriate register (SMHAP1 or SMHAP2).
To read the values of the flags:
1. Read the value of the register and save the index field.
2. Write the index of the register’s flag (i.e., write the index with a 1 in the Index Write bit).
3. Read the settings of the register’s flag.
4. Restore the index field by writing back the value of the index field stored in step 1.
Core-Controlled Access Protection Flags. For core-controlled host access protection there is a read protect and write pro-
tect bit for each block The core block number are parallel to the host blocks for blocks 2-31. The core-controlled host access
protection has a finer granularity for the first two host blocks, which are split into 16 core blocks, indicated as LA0 - LA15.
Host Controller Interface Modules (Continued)
www.national.com 302 Revision1.07
PC87591E/S/L
The block number may be calculated using the following equation:
Core_Block_Number = (CR_Space_Address < 128K) ?
CR_Space_Address[20-0] / 64K : CR_Space_Address[20-0] / 8K
The Shared Memory Core Override Read Protect 0-2 registers and Shared Memory Core Override Write Protect 0-2 regis-
ters provide core access to the read and write protect bits, respectively. Bits in these registers may be set and cleared by
writing to the registers.
Response to a Restricted Access
A restricted access is an access that complies with at least one of the following conditions:
The access type (i.e., Read or Write) of the translated host address (i.e., core address) is protected.
A reset to the core domain due to a Warm reset event or a flash empty indication is set (Core Boot Block field of the
protection word is 11112).
The PC87591x responds to a restricted access by generating an interrupt (if enabled by HERRIEN bit in SMCCST register)
to the core. Two status bits (HWERR and HRERR) indicate whether the restricted access is a read or write access. The
response on the host bus is according to the HERES field.
Forrestrictedwrite accesses: Data written is ignored; when the HERES field is 102, the read or write transactionis completed
with an error SYNC; otherwise, it is completed with a ready SYNC.
For restricted read accesses: When the HERES field is 002, the read or write transaction drives Long Wait (endlessly, unless the
access becomes unrestricted or the HERES field is changed). When the field is 012, the PC87591x completes the transaction
with a ready SYNC and data of 0016; when the field is 102, it completes the transaction with an error SYNC and data of 0016.
Figure 102. Protection Blocks for Protection Bits and Override Protection Bits
Area Not Accessible
to Host
00 0000
01 0000
02 0000
03 0000
0F 0000
10 0000
11 0000
12 0000
1F 0000
1F FFFF
~
~~
~
~
~
~
~
Address in
Core Address
Space
8K
8K
8K
8K
8K
8K
8K
64K
64K
64K
64K
64K
64K
64K
04 0000
00 E000
64K
Host Block
Index Core Override
LA 0
LA 1
LA 2
LA 6
LA 8
LA 15
2
3
15
16
17
31
2
3
15
16
17
31
1
0
MBTA
Block Number
Host Controller Interface Modules (Continued)
Revision 1.07 303 www.national.com
PC87591E/S/L
5.3.6 Random Number Generator (PC87591S)
The PC87591S includes a Random Number Generator unit. Once enabled, this unit can provide up to 800 random bits per
second. The random bits may be read one byte at a time from RNGD register when DVALID bit in RNGCS register is set.
Note that a double buffer scheme is used to improve the performance of bit gathering. The randomization of the data is ver-
ified by compliance with FIPS140-1 specifications.
5.3.7 Signaling Interface
For memory update operations, the host may need to exchange signals (indicating the state) with the core. The Signaling
interface supports this scheme. The scheme is designed mainly for polling-based operations, but it allows the host to inter-
rupt the core.
The signaling hardware includes an 8-bit register that may be read by both host and core. The host may modify bits 0 through
3 of this register; the core may modify bits 4 through 7. A host write to the register sets the Host Semaphore Write (HSEMW)
bit in the Shared Memory Core Control and Status register (SMCCST); if the interrupt enable bit (HSEMIE in SMCCST reg-
ister) is set, the shared memory interrupt to the core is set.
5.3.8 Shared Memory Host Registers
The following set of registers is accessible only by the host. The registers are maintained by VDD.
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
Shared Memory Host Register Map
Offset Mnemonic Register Name Type
0016 SMIMA0 Shared Memory Indirect Memory Address 0 R/W
0116 SMIMA1 Shared Memory Indirect Memory Address 1 R/W
0216 SMIMA2 Shared Memory Indirect Memory Address 2 R/W
0316 SMIMA3 Shared Memory Indirect Memory Address 3 R/W
0416 SMIMD Shared Memory Indirect Memory Data R/W
0516 SMHC Shared Memory Host Control R/W
0616 SMHST Shared Memory Host Status Varies per bit
0716 SMHAP1 Shared Memory Host Access Protect 1 Varies per bit
0816 SMHAP2 Shared Memory Host Access Protect 2 Varies per bit
0C16 SMHSEM Shared Memory Host Semaphore Varies per bit
Figure 103. Signaling Interface
HSEM(3-0)
CSEM(3-0)
Host Side
HSEMW
Writes
Core Side
Host Controller Interface Modules (Continued)
www.national.com 304 Revision1.07
PC87591E/S/L
Shared Memory Indirect Memory Address Register 0 (SMIMA0)
This register defines the addresses 7-0 for a read or write transaction to the memory.
Location: Offset 0016
Type: R/W
Shared Memory Indirect Memory Address Register 1 (SMIMA1)
This register defines addresses 15-8 for a read or write transaction to the memory.
Location: Offset 0116
Type: R/W
Shared Memory Indirect Memory Address Register 2 (SMIMA2)
This register defines addresses 23-16 for a read or write transaction to the memory.
Location: Offset 0216
Type: R/W
Shared Memory Indirect Memory Address Register 3 (SMIMA3)
This register defines addresses 31-24 for a read or write transaction to the memory.
Location: Offset 0316
Type: R/W
Bit 76543210
Name Indirect Memory Address 7-0
Bit Description
7-0 Indirect Memory Address 7-0.
Bit 76543210
Name Indirect Memory Address 15-8
Bit Description
7-0 Indirect Memory Address 15-8.
Bit 76543210
Name Indirect Memory Address 23-16
Bit Description
7-0 Indirect Memory Address 23-16.
Bit 76543210
Name Indirect Memory Address 31-24
Bit Description
7-0 Indirect Memory Address 31-24.
Host Controller Interface Modules (Continued)
Revision 1.07 305 www.national.com
PC87591E/S/L
Shared Memory Indirect Memory Data Register (SMIMD)
This register defines data bits 7-0 for a read or write transaction to the memory.
Location: Offset 0416
Type: R/W
Shared Memory Host Control Register (SMHC)
This register controls the embedded flash operation modes for host-initiated transactions. The register is cleared (0016)on
Host Domain Hardware reset.
Location: Offset 0516
Type: R/W
Shared Memory Host Status Register (SMHST)
This register provides the embedded flash status for host initiated transactions. The register is cleared (0016) on Host Do-
main Hardware reset.
Location: Offset 0616
Type: Varies per bit
Bit 76543210
Name Indirect Memory Data 7-0
Bit Description
7-0 Indirect Memory Data 7-0.
Bit 76543210
Name Reserved PMER Reserved
Reset 00000000
Bit Description
4-0 Reserved.
5PMER (Page Erase). When the bit is set (1), a valid host write to the embedded flash erases the entire page
pointed to by the write address.
This bit can be altered only when HBUSY bit is cleared (0); otherwise results are undefined.
7-6 Reserved.
Bit 76543210
Name Reserved HDERR FMLFULL HBUSY HPERR HEERR
Reset 00000000
Bit Type Description
0 R/W1C HEERR (Host Erase Error). The bit is set (1) when an error occurs during a host-initiated erase. The
bit is cleared by writing 1 to it.
This bit can be cleared only when HBUSY bit is cleared (0).
1 R/W1C HPERR (Host Program Error). The bit is set (1) when an error occurs during a host-initiated program.
The bit is cleared by writing 1 to it.
This bit can be cleared only when HBUSY bit is cleared (0).
2ROHBUSY (Host Busy). Read only. The bit is set (1) when the embedded flash is busy programing or
erasing the flash due to a host-initiated operation.
3ROFMLFULL (Double Buffer Full). Read only. The bit is set (1) when the double buffer is full.
Host Controller Interface Modules (Continued)
www.national.com 306 Revision1.07
PC87591E/S/L
Shared Memory Host Access Protect Register 1 and 2 (SMHAP1-2)
This register holds the read/write protection and lock control from the host side to the shared memory. The memory is par-
titioned into 64 Kbyte blocks. SMHAP1 controls the first 16 blocks (addresses 0-1 Mbyte). SMHAP2 controls the second
group of 16 blocks (addresses 1-2 Mbyte). The block mapping is in the core address space. See “Setting the Host Access
Protection Flags” on page 301 for the calculation method of the block address in the host address space. On Host Domain
Hardware reset, all write-protect flags are set and all lock-protect and read-protect flags are cleared.
Location: Offset 0716 and 0816
Type: Varies per bit
Shared Memory Host Semaphore Register (SMHSEM)
This register provides eight semaphore bits between the core and host. Four of the bits may be set by the host and four may
be set by the core. The register is cleared (0016) on Host Domain Hardware reset.
Location: Offset 0C16
Type: Varies per bit
4 R/W1C HDERR (Host Data Loss Error). The bit is set (1) when a write to a full buffer is detected. The bit is
cleared by writing 1 to it.
This bit can be cleared only when HBUSY bit is cleared (0).
7-5 Reserved.
Bit 76543210
Name Host Access Protection Index Index Write Host Lock
Protection Host Write
Protection Host Read
Protection
Reset 0 0 0 0 0 0 1 0
Bit Type Description
0 R/W Host Read Protection. The block number is as held in the index field (bits 7-4). Note that the Core
Override protection may disable reads even when reads are allowed by this register.
0: Host Reads are allowed for this block
1: Host Reads are inhibited for this block
1 R/W Host Write Protection. The block number is as held in the index field (bits 7-4). Note that the Core
Override protection may disable writes even when writes are allowed by this register.
0: Program and erase are allowed for this block
1: Program and erase are inhibited for this block
2 R/W Host Lock Protection. The block number is as held in the index field (bits 7-4). When set, the bit
prevents changing the values of the Host Read Protect, Host Write Protect and Host Lock Protection
bits for this block. Once set, this bit is cleared by Host Domain Hardware reset only.
0: Changes to protection bits (0-2) for this block are enabled
1: Protection bits (0-2) for this block are locked, and the bits’ values may not be changed
3WOIndex Write. Indicates that this is an index write transaction; therefore, bits 0-2 of this register are
ignored. When read, always returns 0.
0: Write transaction affects all fields of this register (writes to bits 0-2 use the newly written index)
1: Write transaction for purpose of index update; bits 0-2 should not be updated by this write.
7-4 R/W Host Access Protection Index. Holds the index number of the host block accessed by the other fields
in this register. All blocks are 64 Kbytes. The block index is calculated in the core address space. For
details of the address conversion, see Section 5.3.2 on page 297.
Index = Block_First_Address / 64K
In SMHAP1: 0000-111116 for indexes 0-15, respectively
In SMHAP2: 0000-111116 for indexes 16-31, respectively
Bit Type Description
Host Controller Interface Modules (Continued)
Revision 1.07 307 www.national.com
PC87591E/S/L
5.3.9 Shared Memory Core Registers
The following set of registers is accessible only by the core. These registers are maintained by VCC.
For a summary of the abbreviations used for Register Type, see Section 2 on page 34.
Shared Memory Core Register Map
Shared Memory Core Control and Status Register (SMCCST)
This register provides control and status of read/write from/to a restricted address. The register is cleared (0016) on reset.
Location: 00 F90016
Type: R/W
Bit 76543210
Name CSEM3 CSEM2 CSEM1 CSEM0 HSEM3 HSEM2 HSEM1 HSEM0
Reset 0 0 0 0 0 0 0 0
Bit Type Description
3-0 R/W HSEM3-0. Four bits that may be updated by the host and read by both the host and the core.
7-4 RO CSEM3-0. Four bits that may be updated by the core and read by both the host and the core.
Mnemonic Register Name Type
SMCCST Shared Memory Core Control and Status R/W
SMCTA Shared Memory Core Top Address RO in IRE and OBD environments;
R/W in DEV environment
SMHSEM Shared Memory Host Semaphores Varies per bit
SMCORP0-2 Shared Memory Core Override Read Protect 0-2 R/W or RO
SMCOWP0-2 Shared Memory Core Override Write Protect 0-2 R/W or RO
RNGCS Random Number Generator Control and Status Varies per bit
RNGD Random Number Generator Data RO
Bit 76543210
Name HSEMIE HSEMW HLOCK HERES HERRIEN HWERR HRERR
Reset 0 0 0 0 0000
Bit Description
0HRERR (Host Read Error). The bit is set (1) when the host attempts to read from a read-protected block or
out-of-range address. An out-of-range address is an address that the LPC configuration module defines as
mapped to the PC87591x, but it is actually translated to a reserved address in the core address space. Writing
1 to this bit clears it to 0. Writing 0 has no effect.
1HWERR (Host Write Error). The bit is set (1) when the host attempts to write to a read-protected block or out-
of-range address. An out-of-range address is an address that the LPC configuration module defines as mapped
to the PC87591x, but it is actually translated to a reserved address in the core address space. Writing 1 to this
bit clears it to 0. Writing 0 has no effect.
2HERRIEN (Host Error Interrupt Enable). When set (1) and either the HRERR or HWERR bit is set (1), a core
interrupt is generated; otherwise, the core interrupt is inactive.
Host Controller Interface Modules (Continued)
www.national.com 308 Revision1.07
PC87591E/S/L
Shared Memory Core Top Address Register (SMCTA)
This register provides information about the size of the on-chip main block. The register is loaded with its default value on
VCC Power-Up reset only.
Location: 00 F90216
Type: RO in IRE and OBD environments
R/W in DEV environment
Shared Memory Host Semaphore Register (SMHSEM)
This register provides eight semaphore bits between the core and the host. Four of the bits may be set by the host; four may
be set by the core. The register is cleared (0016) on reset.
Location: 00 F90416
Type: Varies per bit
4-3 HERES (Host Error Response). Controls response type on read/write from/to a protected block or out-of-range
address. An out-of-range address is an address that the LPC configuration module defines as mapped to the
PC87591x, but it is actually translated to a reserved address in the core address space.
Bits
4 3 Description
0 0: Drive Long Wait for read; ignore write
0 1: Read back 0016; ignore write
1 0: Drive error SYNC for both read and write
1 1: Reserved
5HLOCK (Host Lock).
0: The bridge does not generate write transactions on the core bus
1: The bridge can generate write transactions on the core bus
This bit should be set only when FMBUSY bit is cleared (see ”Flash Memory Status Register (FLSR)” in
Section 4.16.7 on page 228).
6HSEMW (Host Semaphore Write). The bit is set (1) when the host writes to HSEM register. Writing 1 to this
bit position clears it to 0. Writing 0 has no effect.
7HSEMIE (Host Semaphore Interrupt Enable). When the bit is set (1), the interrupt to the core is set (level
high) if HSEMW is set.
Bit 76543210
Name Reserved MBSD
Reset 0 0 0 2 (see note in field description)
Bit Description
4-0 MBSD (Main Block Size Definition). Defines the size of the main block in 64 Kbyte units. Thus the MBTA value
is MBSD * 1 000016. Note that MBTA is actually the first address beyond the main block.
The reset value of this field is affected by the Force MBTA Zero bit in the protection word (see Section 4.16.6 on
page 226). When the Force MBTA Zero bit is set, the reset value of this field is 016; when the bit is cleared, the
reset value is as shown in the bit table, above.
This field is loaded on VCC Power-Up reset with the on-chip flash size. In DEV environment, the MBSD may be
loaded with a new value.
7-5 Reserved.
Bit 76543210
Name CSEM3 CSEM2 CSEM1 CSEM0 HSEM3 HSEM2 HSEM1 HSEM1
Reset 0 0 0 0 0 0 0 0
Bit Description
Host Controller Interface Modules (Continued)
Revision 1.07 309 www.national.com
PC87591E/S/L
Shared Memory Core Override Read Protect Registers 0-2 (SMCORP0-2)
SMCORP0-2 are 16-bit registers that provide core override on the host read protection bits. For the host to be able to read
a memory location, both the Host Read Protection bit (controlled through the Shared Memory Host Access Protect Register
1 or 2) and the associated bit in SMCORP0-2 should be cleared. Each bit in this register is associated with a memory block,
as described in the bits description. Bits in these registers may be RO or RW depending on their position and the size of the
core and host boot blocks. SMCORP0-2 registers are loaded with reset values either on reset or when the value of the
SMCTA register is changed; the reset values depend on the size of the core and host boot blocks, as defined in the protec-
tion word.
Location: 00 F91016, 00 F91216, 00 F91416
Type: R/W or RO as described in the description below
Bit Type Description
3-0 RO HSEM3-0. Four bits that may be updated by the host and read by both the host and the core.
7-4 R/W CSEM3-0. Four bits that may be updated by the core and read by both the host and the core.
Bit 1514131211109876543210
Name ORPLA15-0
Reset See bit description below 1 See bit description below
Bit 1514131211109876543210
Name ORP15-2 Reserved
Reset See bit description below 0 0
Bit 1514131211109876543210
Name ORP 31-16
Reset See bit description below
Bit Description
15-0 ORPLA15-0 (Override Read Protect Low Addresses 15 through 0).
ORP15-2 (Override Read Protect 15 through 2).
ORP31-16 (Override Read Protect 15 through 0).
Each bit affects the host’s ability to read from one block. On the low addresses (covered by ORPLAi), the block
size is 8 Kbytes. For the other blocks it is 64 Kbytes. The block address is calculated as follows:
Low address blocks, ORPLAi: from i*8K to (i+1)*8K1
Other blocks, ORPLj: from j*64K to (j+1)*64K
See Figure 102 on page 302 for a description of the block mapping. Bit 7 (ORPLA7) in SMCORP0 register is
read only.
0: Do not override the host read protect setting for the block
1: Host read for this block is disabled regardless of the setting of the respective bit in the host register
The reset values of these registers are as follows:
Core boot blocks that cover address 00 000016 to CR_Boot_Block_Size: 1
Host boot blocks not in above group and from (MBTA1Host_Boot_Block_Size) to MBTA: 0
All other blocks: 1
The following access limitations apply to the register bits:
Core boot blocks that cover address 00 000016 to CR_Boot_Block_Size: RO
Host boot blocks not in above group and ranging from (MBTA1Host_Boot_Block_Size) to MBTA:RO
All other blocks: RW
1. Use the MBTA as specified in SMCTA register, without the MBTA override in the protection word.
Host Controller Interface Modules (Continued)
www.national.com 310 Revision1.07
PC87591E/S/L
Shared Memory Core Override Write Protect Registers 0-2 (SMCOWP0-2)
SMCOWP0-2 are 16-bit registers that provide override on the host write protection bits. For the host to be able to write a
memory location, both the Host Write Protection bit (controlled through the Shared Memory Host Access Protect Register 1
or 2) and the associated bit in SMCOWP0-2 should be cleared. Each bit in this register is associated with a memory block,
as described in the bit description. Bits in these registers may be RO or RW depending on their position and the size of the
core and host boot blocks. These registers are cleared on reset and change in value of SMCTA.
Location: 00 F92016, 00 F92216, 00 F92416
Type: R/W
Bit 1514131211109876543210
Name OWPLA15-0
Reset FFFF16
Bit 1514131211109876543210
Name OWP15-2 Reserved
Reset FFFF16
Bit 1514131211109876543210
Name OWP 31-16
Reset FFFF16
Bit Description
15-0 OWPLA15-0(Override Write Protect Low Addresses 15 through 0).
OWP15-2(Override Write Protect 15 through 2).
OWP31-16(Override Write Protect 15 through 0).
Each bit affects the host’s ability to write to one block. On the low addresses (covered by OWPLAi), the block
size is 8 Kbytes. For the other blocks it is 64 Kbytes. The block address is calculated as follows:
Low Address Blocks, OWPLAi: from i*8K to (i+1)*8K1
Other Blocks, OWPLj: from j*64K to (j+1)*64K
See Figure 102 on page 302 for a description of the block mapping. Bit 7 (OWPLA7) in SMCOWP0 register is
read only.
0: Do not override the host Write Protect setting for the block
1: Host writes for this block are disabled regardless of the setting of the respective bit in the host register
The following access limitations apply to the register’s bits:
Core boot blocks that cover address 00 000016 to CR_Boot_Block_Size: RO
Host boot blocks not in above group and ranging from (MBTA1Host_Boot_Block_Size) to MBTA:RO
All other blocks: RW
1. Use the MBTA as specified in SMCTA register, without the MBTA override in the protection word.
Host Controller Interface Modules (Continued)
Revision 1.07 311 www.national.com
PC87591E/S/L
Random Number Generator Control/Status Register, RNGCS (PC87591S)
This register controls the Random Number Generator (RNG) unit. It also provides status of its operation and the validity of
the numbers at its output. The register is cleared on reset.
Location: 00 F93016
Type: Varies per bit
Bit 76543210
Name Reserved CLKP DVALID RNGE
Reset 0 0 0 0 0000
Bit Type Description
0 R/W RNGE (Random Number Generator Enable). Enables the operation of the RNG. This bit should be
cleared to reduce power consumption when the RNG is not required. Some wake-up time may apply
before the first number is generated after RNG activation.
0: RNG disabled (default)
1: RNG enabled
1RODVALID (Data Valid). Indicates that valid data may be read from RNGD register.
0: Data not valid; RNGD always reads 0016 (default)
1: Data valid; a random number is read
4-2 R/W CLKP (Clock Pre-Scaler). Defines the pre-scale ratio between the RNG internal clocks and the core
clock. To change the CLP contents: (a) Clear RNGE; (b) Change CLKP (c); Set RNGE to re-enable the
RNG. CLKP may be set to a value above the actual clock frequency of the core, but it should not be
set to a lower value than the CLK frequency.
Bits
4 3 2 Description
0 0 0: 15-20 MHz (default)
0 0 1: 12-15 MHz
0 1 0: 9-12 MHz
0 1 1: 7-9 MHz
1 0 0: 6-7 MHz
1 0 1: 5-6 MHz
1 1 0: 4-5 MHz
1 1 1: 3-4 MHz
7-5 Reserved.
Host Controller Interface Modules (Continued)
www.national.com 312 Revision1.07
PC87591E/S/L
Random Number Generator Data Register, RNGD (PC87591S)
This register provides the random number value of the RNG.
Location: 00 F93216
Type: RO
5.3.10 Usage Hints
After clearing (0) HLOCK bit, the core firmware should wait until FMBUSY bit is clear (0) before it accesses the on-
chip flash (see ”Flash Memory Status Register (FLSR)” in Section 4.16.7 on page 228).
Enable Access to the shared memory: Before any access may occur, the shared memory access must be enabled
using the SIO Configuration registers (see Section 6.1.11 on page 349). To enable shared memory as a boot device,
the SHBM strap should be set appropriately (see Section 2.2.11 on page 50).
Host boot block may be implemented as part of the on-chip flash or in the external memory. In the latter case, access
to the Host boot block must be enabled by the core after the memory access configuration is completed.
For host shared memory read:
1. Have host enable the memory for reading (if disabled), using SMHAP1 and SMHAP2 registers.
2. Have core enable the memory for reading (in most cases, disabled by default), using SMCORP0-2 registers.
3. Read from the designated address location.
For host shared memory write or erase:
1. Have host enable the desired location for write, using SMHAP1 and SMHAP2 registers (note that the memory
may be disabled for reads if the hardware validation is in use).
2. Have core enable the desired location for a write, using SMCOWP0-2 registers.
3. Enable the host write operations by setting HLOCK bit in SMCCST register.
4. To perform a page erase operation, the host should set PMER bit in SMHC register and write any data to
an address in the page. The page is erased when HBUSY bit in SMHST register is cleared, and an erase
error, if it occurs, is flagged by HEERR bit in SMHST register.
5. To program a byte in the on-chip flash, the host should make sure PMER bit in SMHC register is clear
and write the required data to the designated address location. The programing is completed when HBUSY bit
in SMHST register is cleared. At this time, an erase error, if it occurs, is flagged by HPERR in SMHST register.
6. Programing the expansion memory is done using read/write operations to addresses associated with that memory.
The transactions are passed to the memory through the core bus and BIU modules. The software should perform
the appropriate sequence of read and write operations as required by the flash device in use.
At different stages of the flash programing by the host, communication between the core and host is required. Various
mechanisms may be used for this, one of which is the Shared Memory Semaphore mechanism. This mechanism is
tuned for host-initiated operations that use polling on the registers. The core may receive an interrupt or use polling
to identify a semaphore change. An example of bit allocation is:
Bit 0 - Host requests control of flash
Bit 4 - Core grants control to host
The sequence is:
1. Host sets bit 0 to request control of bus.
2. Core identifies that bit 0 is set and does the required operations, including setting HLOCK bit in
SMCCST register to enable host access.
3. Core sets bit 4, indicating to the host that memory access is granted.
4. Host performs write/erase to the memory, as required.
5. Host clears bit 0, indicating completion of the process.
6. Core clears HLOCK and protects the memory.
7. Core indicates completion of process by clearing bit 4.
Bit 76543210
Name RNGD7-0
Bit Description
7-0 RNGD0-7 (Random Number Generator Data Bits). Provides random data output from the RNG module. When
DVALID in RNGCS register is cleared, RNGD register always reads 0016. When DVALID in RNGCS register is
set, the data read is a random number. Any random number can be read only once, after which it is marked as
invalid and replaced by a new number.
Host Controller Interface Modules (Continued)
Revision 1.07 313 www.national.com
PC87591E/S/L
5.4 CORE ACCESS TO HOST-CONTROLLED MODULES
The PC87591x enables the core to access the Host-Controlled module registers (e.g., host configuration module, RTC and
MSWC), using the SuperI/O Internal Bus (SIB) controller.
Host-Controlled Modules Register Arbitration. SincethehostprocessorsoftwareandthePC87591xfirmwarecannotac-
cess a Host-Controlled module simultaneously, they must communicate to prevent conflicts in Host-Controlled module reg-
ister usage.
Access to the Host-Controlled modules is controlled via a lock bit for each module. When the relevant lock bit is cleared,
access to the Host-Controlled modules registers by the host processor is enabled. When the relevant lock bit is set, access
to the Host-Controlled module registers by the host processor is blocked (i.e., write operations are ignored and read opera-
tions return 0016). Any attempt by the host to access the locked register is flagged by setting the respective bit in SIOLV
register.
SIB Arbitration. The host and core should access the Host-Controlled modules only after preventing host access to the
module (using lock bits, as explained in the previous paragraph). The SIB controller arbitrates SIB usage between the host
and core. If a core transaction starts after an LPC transaction has started, it waits for the completion of the LPC transaction.
If a core transaction starts before an LPC transaction starts, the core transaction finishes before handling the LPC transac-
tion.
The PC87591x firmware may access the Host-Controlled modules only while the core domain is in Active mode, the Host
Domain power plane is on and the host domain clock is enabled with a minimum operation frequency of TBD.
Core Read Operation. To perform a read operation by the core from a Host-Controlled module register:
1. Set CSAE bit in SIBCTRL register, if not already set.
2. Verify that both CSRD and CSWR bits in SIBCTRL register are cleared.
3. Select the device to be accessed by setting its respective bit in CRSMAE register, if not already set. All other bits in the
register must be cleared.
4. Specify the offset of the register in the device in IHIOA register, if not already specified.
5. Write 1 to CSRD bit in SIBCTRL register.
6. Read the CSRD bit in SIBCTRL until it returns 0.
7. Read the data from IHD register.
Core Write Operation. To perform a write operation by the core from a Host-Controlled module register:
1. Set CSAE bit in SIBCTRL register, if not already set.
2. Verify that both CSRD and CSWR bits in SIBCTRL register are cleared.
3. Select the device to be accessed by setting its respective bit in CRSMAE register, if not already set. All other bits in the
register must be cleared.
4. Specify the offset of the register in the device in IHIOA register, if not already specified.
5. Write the data to IHD register; this starts the write operation to the device.
6. Read the CSWR bit in SIBCTRL until it returns 0; this indicates the completion of the write transaction.
The following sequence is provided for minimal conflict between host and core in the use of Host-Controlled peripherals.
1. After arbitrating the use of the specific Host-Controlled modules with the host, set the corresponding lock bit (see
LKSIOHA register).
2. Read and save all Host-Controlled module registers required for proper operation of the host. Beware of destructive
reads.
3. After the Host-Controlled module access is complete, restore the Host-Controlled module registers saved in step 2.
4. Clear the corresponding lock bit to allow the host to access the Host-Controlled module.
When accessing the RTC, also:
1. To access locked memory locations in the RTC, set (1) RTCMR bit in SIBCTRL register to clear the RTC lock bits.
2. Access the RTC’s CMOS-RAM and its registers. To prevent conflicts with the host software, the firmware should not read
any of the RTC read-volatile registers.
3. After the RTC access is complete, if the RTC locking was removed, re-lock the RTC memory and restore the RTC mem-
ory bank selection and the address pointer.
Host Controller Interface Modules (Continued)
www.national.com 314 Revision1.07
PC87591E/S/L
5.4.1 Core Access to Host-Controlled Module Registers
The following set of registers is accessible only by the core. The registers are powered by VCC.
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
Core Access to Host-Controlled Modules Register Map
Indirect Host I/O Address Register (IHIOA)
This register defines the host I/O address for read or write transactions from/to the Host-Controlled modules. The I/O ad-
dress is an offset from the least significant bits of the device address. The accessed device is selected using the Core to
SIB Modules Access Enable Register (CRSMAE); see page 316.
Location: 00 FCE016
Type: R/W
Indirect Host Data Register (IHD)
This register holds host data for read or write transactions from/to the Host-Controlled modules.
Location: 00 FCE216
Type: R/W
Mnemonic Register Name Type
IHIOA Indirect Host I/O Address R/W
IHD Indirect Host Data R/W
LKSIOHA Lock SuperI/O Host Access R/W
SIOLV SuperI/O Access Lock Violation R/W1C
CRSMAE Core to SIB Modules Access Enable R/W
SIBCTRL SIB Control Varies per bit
Bit 1514131211109876543210
Name Reserved Indirect Host I/O Offset
Reset 0 000000000000000
Bit Description
7-0 Indirect Host I/O Offset. Only offsets within the device range are allowed. Other offsets may have unpredictable
results.
15-8 Reserved.
Bit 76543210
Name Indirect Host Data
Reset 00000000
Bit Description
7-0 Indirect Host Data.
Host Controller Interface Modules (Continued)
Revision 1.07 315 www.national.com
PC87591E/S/L
Lock SuperI/O Host Access Register (LKSIOHA)
This register controls locking of host access to the Host-Controlled modules. All bits of this register, except bit 1, are cleared
on reset. The bit 1 reset value is defined by RTC Lock Default bit in “Protection Word” on page 226.
Location: 00 FCE416
Type: R/W
SuperI/O Access Lock Violation Register (SIOLV)
This register provides an error indication when a host lock violation occurs on Host-Controlled modules access.
Location: 00 FCE616
Type: R/W1C
Bit 76543210
Name Reserved LKRTCHA LKCFG
Reset 000000seetext0
Bit 15 14 13 12 11 10 9 8
Name Reserved
Reset 00000000
Bit Description
0LKCFG (Lock Configuration Registers Host Access).
0: Host processor access to the Configuration registers is enabled
1: Host processor access to the Configuration registers is blocked
1LKRTCHA (Lock Real-Time Clock (RTC) Host Access).
0: Host processor access to the RTC registers is enabled
1: Host processor access to the RTC registers is blocked
15-2 Reserved.
Bit 76543210
Name Reserved RTCLV CFGLV
Reset 00000000
Bit 15 14 13 12 11 10 9 8
Name Reserved
Reset 00000000
Bit Description
0CFGLV (Configuration Register Lock Violation). The bit is set (1) when the host processor attempts to access
the configuration registers while LKFDCHA bit in LKSIOHA register is set.
1RTCLV (Real-Time Clock (RTC) Lock Violation). The bit is set (1) when the host processor attempts to access
the RTC while LKRTCHA bit in LKSIOHA register is set.
15-2 Reserved.
Host Controller Interface Modules (Continued)
www.national.com 316 Revision1.07
PC87591E/S/L
Core to SIB Modules Access Enable Register (CRSMAE)
This register enables core access to the Host-Controlled modules. Only one of the bits in this register may be set at a time.
Location: 00 FCE816
Type: R/W
Bit 76543210
Name Reserved RTCAE CFGAE
Reset 00000000
Bit 15 14 13 12 11 10 9 8
Name Reserved MSWCAE
Reset 00000000
Bit Description
0CFGAE (Configuration Register Core Access Enable).
0: Core access to the Configuration registers is disabled
1: Core access to the Configuration registers is enabled
1RTCAE (Real-Time Clock (RTC) Core Access Enable). The RTC has two chip-select signals defined in its
configuration space, each with two registers. A1 of the offset is used to differentiate between the two (when A1
is 0, the pair pointed to by index 60, 61 is accessed; when A1 is 1, the pair pointed to by index 62, 63 is
accessed).
0: Core access to the RTC registers is disabled
1: Core access to the RTC registers is enabled
7-2 Reserved.
8MSWCAE (Mobile System Wake-Up Control (MSWC) Access Enable).
0: Core access to the MSWC registers is disabled
1: Core access to the MSWC registers is enabled
15-9 Reserved.
Host Controller Interface Modules (Continued)
Revision 1.07 317 www.national.com
PC87591E/S/L
SIB Control Register (SIBCTRL)
This register allows the core to control the SIB controller operation.
Location: 00 FCEA16
Type: Varies per bit
Bit 76543210
Name Reserved RTCMR CSWR CSRD CSAE
Reset 00000000
Bit Type Description
0 R/W CSAE (Core to SIB Access Enabled).
0: Core access to the SIB bus is disabled (default)
1: Core access to the SIB bus is enabled. The device to be accessed is selected by the SIB Device Select
register.
1 R/W1S CSRD (Core Read from SIB). Writing 1 to this bit starts a read from the SIB; the read is based on the
address and enabled device specified in CRSMAE register. A write of 0 to this bit is ignored. This bit
is cleared when the read operation is completed, indicating that the data is ready in IHD register.
2ROCSWR (Core Write to SIB). The bit is set by a write operation to IHD register. It is cleared when the
write to the SIB is completed.
3 R/W1S RTCMR (Real-Time Clock (RTC) Master Reset). Writing 1 to this bit generates a reset pulse to the
RTC module. This bit is cleared by the hardware once the reset pulse is completed. Writing 0 to this
bit is ignored.
7-4 Reserved.
Host Controller Interface Modules (Continued)
www.national.com 318 Revision1.07
PC87591E/S/L
5.5 MOBILE SYSTEM WAKE-UP CONTROL (MSWC)
The MSWC detects and handles wake-up events from various sources in the host-controlled modules. The MSWC gener-
ates interrupts to the host via SMI or PWUREQ, and/or alerts the core, which enables the core to control the wake-up se-
quence. Since the MSWC is powered by VCC, it can operate in low power consumption states. Some MSWC operations
depend on the presence of a clock; these functions are not available when the core clock is turned off.
Figure 104 shows the block diagram of the MSWC.
5.5.1 Features
The MSWC recognizes the following maskable system events:
Modem ring (RI1 and RI2 pins)
Telephone ring (RING input pin)
Wake-up on module IRQs for RTC, KBD and Mouse
Software events
Software triggered wake-up event
ACPI power state change indications
Software off command
The MSWC notifies the host and/or core when any of the above events occur by asserting one or more of the following output
pins:
Power-Up Request (PWUREQ)
System Management Interrupt (SMI)
Interrupt to the host (IRQ)
MSWC interrupt to the core
5.5.2 Wake-Up Event Detection and Status Bits
The MSWC monitors various system signals for a wake-up event. When an event is detected, a status bit is set to record it.
Each event goes to the Wake-Up Mode Control Logic, which determines its effect (see Figure 105 for an illustration of this
mechanism). A set of dedicated registers is used to determine the wake-up criteria, including the RING detection mode.
Figure 104. MSWC Block Diagram
Core Peripheral Bus
Host Domain Internal Bus
Wake-Up
Configuration
RI1 RI2
Modules’ IRQs
RING Input
SMI
PWUREQ
Status Registers
Configuration
Registers
Off Event
RTC Alarm
SMI
MSWC Interrupt
Control &
Wake-Up
Event
Detection IRQ
PM I/F
Channels
Host Controller Interface Modules (Continued)
Revision 1.07 319 www.national.com
PC87591E/S/L
The following wake-up input events are detected by the MSWC:
Software events
IRQ from SuperI/O modules
Modem Ring (RI1 and RI2)
Telephone Ring (RING input)
ACPI state change
Legacy off event
RTC Alarm
When an input event is detected, the corresponding status bit in both host and core status registers is set to 1, regardless
of any Routing Enable bit setting. If both the status bit and a Routing Enable bit corresponding to a specific event are set to
1 (no matter in what order), the output pin corresponding to that Routing Enable bit is asserted.
A status bit is cleared by writing 1 to it. Writing 0 to a status bit does not change its value. Clearing the routing enable bit of
an event prevents it from issuing the corresponding system notification (output event) but does not affect the status bit.
Figure 105 shows the routing scheme of detected wake-up events to the various means of system notification (i.e., output
events).
Both the core and the host have status registers; thus both core and host software can monitor the various event status bits.
This enables handling of events via wake-up logic that is implemented as part of the Embedded Controller firmware, and
passing the wake-up notifications through the Power Management host-interface protocol. The core uses a mask register
(WK_SMIENn) to define which of the status bits it should respond to.
It is recommended that each of the wake-up sources be handled by one handler routine on the host (i.e., SMI, SCI or IRQ
triggered) or the core.
Software Event
A software event may be used to trigger a wake-up event via software control. A software event to the host is active when
the Software Event Status bit in WK_STS0 register is set. A software event to the core is active when the Software Event
Status bit in MSHES0 register is set.
The software event may be activated (i.e., the status bits in WK_STS0 and MSHESO registers are set) by writing 1 to the
Software Event Status bit in WK_STS0 register when the bit is cleared. Once this bit is set to 1, writing 1 to the bit clears it.
WK_STS0 is accessible by the host only when VDD is present. The software event can be activated by the host only when
VDD is present. The software event may be activated by the core by the core access to the Host-Controlled Module bridge
even when VDD is off.
When HSECM bit in MSWCTL1 register is cleared, the Software Event Status bit in MSHES0 is set on a change of the re-
spective bit in WK_STS0 register from 0 to 1. When HSECM bit is set, the Software Event Status bit in MSHES0 is set on a
write of a 1 to the respective bit in WK_STS0. The Software Event Status bit in MSHES0 is cleared by writing 1 to it.
Module IRQ Wake-Up Event
A module IRQ wake-up event is defined as the leading edge of the IRQ assertion of the RTC.
To enable the IRQ of a specific logical device to trigger a wake-up event, the associated enable bit must be set to 1. This is
bit 4 of the Interrupt Number and Wake-Up on IRQ Enable register, located at index 7016 in the configuration space of the
logical device (see Table 52 on page 339). When this bit is set, any IRQ assertion of the corresponding logical device acti-
vates the module IRQ wake-up event. Therefore, the module IRQ wake-up event is a combination of all IRQ signals of the
logical devices for which wake-up on IRQ is enabled.
When the event is detected as active, its associated status bit (bit 7 of WK0_STS register) is set to 1. If the associated enable
bit (bit 7 of WK_EN0 register) is also set to 1, the PWUREQ output is asserted and remains asserted until the status bit is
cleared.
Since VDD powers IRQ generation of the logical devices, a module IRQ event can be activated only when VDD is present
(see Section 6.1 on page 335 for a list of logical devices).
Modem Ring
High to low transitions on RI1 (or RI2) indicate the detection of a ring in an external modem connected to Serial Port 1 (or
Serial Port 2) and can be used as wake-up events.
Telephone Ring
A telephone ring is detected by the MSWC by processing the raw signal coming directly from the telephone line into the
RING input pin. Detection of a pulse train, with a frequency higher than 16 Hz lasting at least 0.19 sec, is used as a wake-
up event.
Host Controller Interface Modules (Continued)
www.national.com 320 Revision1.07
PC87591E/S/L
The RING pulse-train detection is achieved by monitoring the falling edges on RING in time slots of 62.5 msec (a 16 Hz
cycle). A positive detection occurs if falling edges of RING are detected in three consecutive time slots, following a time slot
in which no RING falling edge is detected. This detection method guarantees the detection of a RING pulse train with fre-
quencies higher than 16 Hz. It filters out (does not detect) pulses of less than 10 Hz and may detect pulses between 10 Hz
and 16 Hz.
ACPI State Change and Legacy Off Events
The host may operate in either Legacy or ACPI mode. The operation mode is specified by the Power Button Mode bit in
SuperI/O Configuration D register (SIOCFD). When EICFGPBM bit in MSIEN2 register is set, a change to the Power Button
Mode bit generates an interrupt to the core. The core may read the value of the Power Button Mode bit, using CFGPBM bit
in MSWCTL2 register, to determine how to interpret the other power state request bits.
The Power Supply Off bit in SIOCFD register may be used in Legacy mode to indicate a request to turn power off. A write
of 1 to this bit sets CFGPSO bit in MSWCTL2 register; then, if EICFGPSO bit in MSIEN2 register is set, an interrupt to the
core is generated, indicating the event.
A set of System State Change Request bits (S1-S5) are provided in WK_STATE register. The host uses these bits for ACPI-
compliant state change requests. A write of 1 to any of these bits indicates a state change request to the core through the
respective bit in MSWCTL2 register. When all bits in WK_STATE are written with 0, a request of S0 is indicated, and ACPIS0
bit in MSWCTL2 register is set. When any S0-S5 bit in MSWCTL2 is set and the respective mask bit in MSIEN2 register is
set, an interrupt to the core is generated whenever a change to any of the state bits is detected.
All interrupt requests may be cleared by writing 1 to the corresponding status bit or by masking the event (by clearing the
corresponding Interrupt Enable bit).
RTC Alarm
The RTC module may generate an ALARM signal (see Section 6.2.8 on page 359). The RTC alarm can serve as a wake-
up request to wake up the system; the request is routed to the core, which then wakes up the system. To enable an alarm
wake-up, the following settings should be made:
Set the Alarm conditions in the RTC module. By masking the various interrupts, software may select a wake-up either
to the host directly, using the RTC’s IRQ, or to the core through the Alarm signal.
Enable the Wake-Up on Alarm status interrupt masking (optional, for Interrupt Enabled mode) by setting EIRTCAL bit
in MSIEN2 register.
Verify that the RTCAL bit in MSWCTL3 bit is cleared (no pending Alarm request).
Enable the Wake-Up on MSWC event in the MIWU and ICU modules.
Verify that the ALARM bit in the RTC is cleared.
After an ALARM event is detected in the RTC, the RTC ALARM status bit is set (bit 5 in CRC register, page 369); in re-
sponse, RTCAL bit in MSWCTL3 register is set.
When handling an ALARM event, make sure that no events are lost by clearing RTCAL bit before clearing the ALARM status
in the RTC.
5.5.3 Wake-Up Output Events
The MSWC generates four types of output events:
IRQ - an interrupt routed as configured in the MSWC PnP configuration registers.
PWUREQ - an event that is typically routed to an input in the chipset that triggers an SCI event.
SMI - an event typically connected to an input in the chipset that triggers an SMI event.
MSWCI - an interrupt to the MIWU module in the core domain. This enables the core firmware to handle the wake-
up events.
Figure 105 illustrates the enabling mechanism and the event generation scheme for the various output events. Output
events to the host are generated for input events that have their status bit set (WK_STSn.i is 1). Output events to the core,
through the MIWU, are generated for input events that have their core status bit set (MSHESn.ii is 1).
Each of the three Host Wake-Up Event Routing Control registers (WK_ENn, WK_SMIENn and WK_IRQENn) holds a Rout-
ing Enable bit for each event; this allows selective routing of these events to PWUREQ, SMI and/or the assigned MSWC
interrupt request (IRQ) channel, respectively.
After an output event is asserted, it is active until all set status bits are cleared or masked. The current status of the event
may be read at the ACPI status registers in the chipset’s ACPI controller or by reading “Wake-Up Event Status Register 0
(WK_STS0)” on page 323 and “Wake-Up Signals Value Register (WK_SIGV)” on page 325.
As shown in Figure 106, for SMI output events, the MSWC combines the event request coming from the Host Interface’s
Power Management channels 1 and 2 with MSWC internal SMI events; for PWUREQ output events, the MSWC combines
the PWUREQ events generated in the MSWC module with wake-up requests associated with the IRQ configuration regis-
ters.
Host Controller Interface Modules (Continued)
Revision 1.07 321 www.national.com
PC87591E/S/L
The SMI may be output from the PC87591x using the dedicated SMI signal or by routing SMI to an interrupt request channel
via the device’s configuration registers.
The Wake-Up Event Routing Control register, MSHEIEn, which is controlled by the core, holds an enable bit for each of the
events, which allows selective routing of these events to the core wake-up interrupt (MSWCI) to the MIWU. The core event
is controlled using a separate set of status signals to prevent race conditions when clearing events.
The MSWCI interrupt is a level high interrupt that gathers requests from MSHESn, MSWCTL2 and MSWCTL3 registers.
Once an output event is asserted, it keeps its active state until all set status bits are cleared or masked. This interrupt signal
is connected to the MSWC wake-up input of the MIWU. This enables handling state change requests even in Idle mode.
The MSWC output for this input is connected to the core through the MIWU module, enabling a power state change on in-
terrupt.
Event i
Detection
WK_SMIENn.i
WK_IRQENn.i
WK_ENn.i
Wake-Up Event i
From Wake-Up
PWUREQ
SMI
IRQ
Event
Routing
Logic
WK_STSn.i
Extension Logic
To Peripheral Bus
MSHEIEn.i MSWCI
to MIWU
MSHESn.i
Figure 105. Wake-Up Event Routing Scheme
Wake-Up
From Host
I/F Module
SMI
Module SMI
PWUREQ
IRQj Wake-Up
PWUREQ Wake-Up Module
Wake-Up IRQi Wake-Up
Figure 106. SMI and PWUREQ Source Gathering Scheme
from IRQs
Routing
PM1SMI
PM2SMI
Host Controller Interface Modules (Continued)
www.national.com 322 Revision1.07
PC87591E/S/L
5.5.4 Other MSWC Controlled Elements
In addition to its Power Management functions, the MSWC controls the handling of the following system control elements:
Host Configuration Address Selection
Host Keyboard Reset Fast Reset Output (KBRST)
GA20 Pin Functionality
Host Power on indication
Host Configuration Address Selection
The standard strap configuration enables the selection of one of two SuperI/O configuration register addresses. When the
PC87591x is enabled in Programmable Configuration Address mode (see Table 47 on page 335), the core may set the ad-
dress of the SuperI/O configuration index/data registers.
HCFGBAL and HCFGBAH are byte-wide read/write registers. HCFGBAL holds the least significant byte of a host mother-
board PnP initial configuration address; HCFGBAH holds the most significant byte. The contents of HCFGBAH and HCFG-
BAL change only during VCC Power-Up reset.
To update the base address of the SuperI/O configuration index/data registers, do the following:
1. Clear VHCFGA bit in MSWCTL1 register by writing 1 to it.
2. Write the lower byte of the address to HCFGBAL (MSB must be cleared).
3. Write the higher byte of the address to HCFGBAH.
4. Set HCFGLK bit to prevent an accidental change of the address written to HCFGBAL and HCFGBAH.
The base address is preserved by VCC, and VHCFGA is set as long as a valid address is maintained. If there is no valid
configuration base address, the LPC interface does not respond to configuration requests.
Host Keyboard Fast Reset
The Host Keyboard Reset output (KBRST) is an output of the PC87591x that serves as one of the sources for Host Soft
reset commands (i.e., INIT input in the x86 processors). Figure 107 shows the KBRST generation scheme. The host is reset
when the KBRST output is low. A reset command is issued by the PC87591x by software or hardware, as follows:
Software: The core firmware can issue a reset command to the host by writing 1 to HRSTOB in MSWCTL1 register.
The reset to the host ends by writing 0 to this bit.
Hardware: The host is reset during VCC Power-Up reset if HRAPU bit in MSWCTL3 register is set and an LPC trans-
action is started. This is used to prevent accesses to the PC87591x from being ignored due to the duration of the
Power-Up reset.
.
GA20 Pin Functionality
The GA20 (Gate Address A20) function is part of the PC architecture. In PC87591x, the GA20 function is implemented by a
GPIO signal that is configured as output. Port PB5 is recommended to be used as GA20 since its default state after reset is
output driving high. The firmware running on the core may change the GA20 signal state by modifying bit 5 in PBDOUT reg-
ister. There is no special hardware or multiplexing on PB5; since there is no multiplexing, bit 5 of PBALT register is always
0 and any writes to it are disregarded. PB5 may be used as a GPIO; however, note that wake-up for PB5 differs from the
other signals in port B.
Host Reset
Extend Logic
Figure 107. KBRST Generation Scheme
HRSTOB bit (MSWCTL1)
HRAPU bit (MSWCTL3) =1
VCC Power-Up Reset
IOPB6
Logic
LPFTO bit (MSWCLT3) =1
LPCPD = 0
LPC Transaction Detected
KBRST
Host Controller Interface Modules (Continued)
Revision 1.07 323 www.national.com
PC87591E/S/L
5.5.5 MSWC Host Registers
The MSWC registers are organized in four banks, all of which are battery-backed. The offsets are related to a base address
that is determined by the MSWC Base Address register in the device configuration registers. The lower 19 offsets are com-
mon to the four banks; the upper offsets (1316-1F16) are divided as follows:
Bank 0 is reserved.
Bank 1 is reserved.
Bank 2 holds the Event Routing Configuration and Wake-Up Extension Control registers.
The active bank is selected through the Configuration Bank Select field (bits 1-0) in the Wake-Up Configuration register
(WK_CFG).
As a programing aid, the registers are described in this chapter according to the following functional groupings:
General status
Enable
Configuration
Routing
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
MSWC Host Register Map
The following tables list the MSWC host registers. For the MSWC core register map, see Section 5.5.6 on page 328.
Table 44. Banks 0, 1, 2 and 3 - The Common Control and Status Register Map
Table 45. Bank 2 - Event Routing Configuration Register Map
Wake-Up Event Status Register 0 (WK_STS0)
This register is set to 0016 on VPP power-up, VCC power-up or Host Domain Software reset. It indicates which wake-up
events, associated with the register, have occurred. Writing 1 to a bit clears it to 0. Writing 0 has no effect. Bit 6 behaves in
a special way, as described in the table below.
Location: Offset 0016
Type: R/W1C
Offset Mnemonic Register Name Type
0016 WK_STS0 Wake-Up Event Status 0 R/W1C
0216 WK_EN0 Wake-Up Enable 0 R/W
0416 WK_CFG Wake-Up Configuration R/W
0616 WK_SIGV Wake-Up Signal Value RO
0716 WK_STATE Wake-Up ACPI State WO
Other Reserved
Offset Mnemonic Register Name Type
1316 WK_SMIEN0 Wake-Up SMI Enable 0 R/W
1516 WK_IRQEN0 Wake-Up Interrupt Request Enable 0 R/W
Other Reserved
Bit 76543210
Name Module IRQ
Event
Status
Software
Event
Status Reserved RING
Event
Status Reserved RI2
Event
Status
RI1
Event
Status
Reset 00000000
Host Controller Interface Modules (Continued)
www.national.com 324 Revision1.07
PC87591E/S/L
Wake-Up Events Enable Register (WK_EN0)
This register is set to 0016 on VPP power-up or Host Domain Software reset. When enabled wake-up events are detected,
the PWUREQ signal is activated.
Location: Offset 0216
Type: R/W
Bit Description
0RI1 Event Status.
0: Event not detected (default)
1: Event detected
1RI2 Event Status.
0: Event not detected (default)
1: Event detected
2Reserved.
3RING Event Status. RING event detection, according to the RING detection mode enabled.
0: Event not detected (default)
1: Event detected
5-4 Reserved.
6Software Event Status. This bit may work in two modes, as defined by HSECM bit in MSWCTL1 register (see
“MSWC Control Status Register 1 (MSWCTL1)” on page 329).
When HSECM is 0, writing 1 to Software Event Status bit inverts its value.
When HSECM is 1, writing 1 to Software Event Status bit sets it; the bit is cleared by a write of 1 to bit 6 in
MSHES0 register.
0: Event not active (default)
1: Event active
7Module IRQ Event Status. This sticky bit shows the status of the module IRQ event detection.
0: Event not active (default)
1: Event active
Bit 76543210
Name Module IRQ
Event
Enable
Software
Event
Enable Reserved RING
Event
Enable Reserved RI2
Event
Enable
RI1
Event
Enable
Reset 00000000
Bit Description
0RI1 Event Enable.
0: Disabled (default)
1: Enabled
1RI2 Event Enable.
0: Disabled (default)
1: Enabled
2Reserved.
3RING Event Enable.
0: Disabled (default)
1: Enabled
Host Controller Interface Modules (Continued)
Revision 1.07 325 www.national.com
PC87591E/S/L
Wake-Up Configuration Register (WK_CFG)
This register is set to 0016 on VPP power-up or Host Domain Software reset. It enables access to Event Routing Control
registers (bank selected).
Location: Offset 0416
Type: R/W
Wake-Up Signals Value Register (WK_SIGV)
This is a read-only register that returns the value of SMI and PWUREQ signal output and input to this module. This register
helps to identify the source of the wake-up request when multiple sources are enabled.
Location: Offset 0616
Type: RO
5-4 Reserved.
6Software Event Enable.
0: Disabled (default)
1: Enabled
7Module IRQ Event Enable.
0: Disabled (default)
1: Enabled
Bit 76543210
Name Reserved Configuration Bank
Select
Reset 00000000
Required 0 0
Bit Description
1-0 Configuration Bank Select.
Bits
1 0 Bank Register
0 0: 0 Reserved
0 1: 1 Reserved
1 0: 2 Event Routing, Wake-Up Extension
1 1: 3 Reserved
7-2 Reserved.
Bit 76543210
Name Reserved PWUREQof
Wake-Up
Value
PWUREQ
Output
Value
PM2 SMI
Output
Value
PM1 SMI
Output
Value
SMI Wake-
Up Output
Value
SMI Output
Value
Bit Description
Host Controller Interface Modules (Continued)
www.national.com 326 Revision1.07
PC87591E/S/L
Wake-Up ACPI State Register (WK_STATE)
This is a read/write register. It always returns 0016 when read.
Location: Offset 0716
Type: R/W
Bit Description
0SMI Output Value.
0: SMI output is low (asserted)
1: SMI output is high (de-asserted)
1SMI Wake-Up Output Value.
0: SMI output of the wake-up module is low (asserted)
1: SMI output of the wake-up module is high (de-asserted)
2PM1 SMI Output Value.
0: SMI output of the Power Management channel 1 is low (asserted)
1: SMI output of the Power Management channel 1 is high (de-asserted)
3PM2 SMI Output Value.
0: SMI output of the Power Management channel 2 is low (asserted)
1: SMI output of the Power Management channel 2 is high (de-asserted)
4PWUREQ Wake-Up Output Value.
0: PWUREQ output is low (asserted)
1: PWUREQ output is high (de-asserted)
5PWUREQ Wake-Up Value.
0: PWUREQ output of the wake-up module is low (asserted)
1: PWUREQ output of the wake-up module is high (de-asserted)
7-6 Reserved.
Bit 76543210
Name Reserved S5 S4 S3 S2 S1 Reserved
Bit Description
0Reserved.
1S1 (Request to Change to S1 State). A write of 1 to this bit indicates to the core that the host requests to
change to S1 state. The S state and transition are interpreted, as specified in the ACPI standard for S state
change requests. This bit always reads back 0.
0: Not an S1 state request
1: S1 state setting request
2S2 (Request to Change to S2 State). A write of 1 to this bit indicates to the core that the host requests to
change to S2 state. The S state and transition are interpreted, as specified in the ACPI standard for S state
change requests This bit always reads back 0.
0: Not an S2 state request
1: S2 state setting request
Host Controller Interface Modules (Continued)
Revision 1.07 327 www.national.com
PC87591E/S/L
Wake-Up Event Routing to SMI Enable Register 0 (WK_SMIEN0)
This register is set to 0016 on VPP power-up or Host Domain software reset. It controls the routing of detected wake-up
events to the SMI signal. Detected wake-up events that are enabled activate the SMI signal regardless of the value of
WK_EN0 register.
Location: Bank 2, Offset 1316
Type: R/W
3S3 (Request to Change to S3 State). A write of 1 to this bit indicates to the core that the host requests to
change to S3 state. The S state and transition are interpreted, as specified in the ACPI standard for S state
change requests. This bit always reads back 0.
0: Not an S3 state request
1: S3 state setting request
4S4 (Request to Change to S4 State). A write of 1 to this bit indicates to the core that the host requests to
change to S4 state. The S state and transition are interpreted, as specified in the ACPI standard for S state
change requests. This bit always reads back 0.
0: Not an S4 state request
1: S4 state setting request
5S5 (Request to Change to S5 State). A write of 1 to this bit indicates to the core that the host requests to
change to S5 state. The S state and transition are interpreted, as specified in the ACPI standard for S state
change requests. This bit always reads back 0.
0: Not an S5 state request
1: S5 state setting request
7-6 Reserved.
Bit 76543210
Name Reserved Software
Event to
SMI Enable Reserved RING
Event to
SMI Enable Reserved RI2
Event to
SMI Enable
RI1
Event to
SMI Enable
Reset 00000000
Bit Description
0RI1 Event to SMI Enable.
0: Disabled (default)
1: Enabled
1RI2 Event to SMI Enable.
0: Disabled (default)
1: Enabled
2Reserved.
3RING Event to SMI Enable.
0: Disabled (default)
1: Enabled
5-4 Reserved.
6Software Event to SMI Enable.
0: Disabled (default)
1: Enabled
7Reserved.
Host Controller Interface Modules (Continued)
www.national.com 328 Revision1.07
PC87591E/S/L
Wake-Up Event Routing to IRQ Enable Register 0 (WK_IRQEN0)
This register is set to 0016 on VPP power-up or Host Domain Software reset. It controls the routing of detected wake-up
events to the assigned MSWC interrupt request (IRQ) channel. Detected wake-up events that are enabled activate the as-
signed IRQ channel regardless of the value of WK_EN0 register.
Location: Bank 2, Offset 1516
Type: R/W
5.5.6 MSWC Core Registers
For a summary of the abbreviations used for Register Type, see Section 2 on page 34.
Table 46. MSWC Core Register Map
Bit 76543210
Name Reserved Software
Event to
IRQ Enable Reserved RING
Event to
IRQ Enable Reserved RI2
Event to
IRQ Enable
RI1
Event to
IRQ Enable
Reset 00000000
Bit Description
0RI1 Event to IRQ Enable.
0: Disabled (default)
1: Enabled
1RI2 Event to IRQ Enable.
0: Disabled (default)
1: Enabled
2Reserved.
3RING Event to IRQ Enable.
0: Disabled (default)
1: Enabled
5-4 Reserved.
6Software Event to IRQ Enable.
0: Disabled (default)
1: Enabled
7Reserved.
Mnemonic Register Name Type
MSWCTL1 MSWC Control Status Register 1 Varies per bit
MSWCTL2 MSWC Control Status Register 2 Varies per bit
MSWCTL3 MSWC Control Status Register 3 R/W
HCFGBAL Host Configuration Base Address Low R/W
HCFGBAH Host Configuration Base Address High R/W
MSIEN2 MSWC Interrupt Enable Register 2 R/W
MSHES0 MSWC Host Event Status Register 0 R/W1C
MSHEIE0 MSWC Host Event Interrupt Enable Register R/W
Host Controller Interface Modules (Continued)
Revision 1.07 329 www.national.com
PC87591E/S/L
MSWC Control Status Register 1 (MSWCTL1)
This is a byte-wide read/write register that controls the settings associated with host wake-up and activity. The contents of
this register are preserved by VCC. Bit 0 is cleared by Warm reset; other bits are reset only on VCC Power-Up reset.
Location: 00 FCC016
Type: Varies per bit
Bit 76543210
Name Reserved HSECM HCFGLK VHCFGA LPCRSTA HPWRON HRSTOB
Reset 000000- -
Bit Type Description
0 R/W HRSTOB (Host Reset Out Bit). Enables the PC87591x to generate a Host Soft reset via firmware,
using the KBSTO pin. The pin is held low (reset is active) for as long this bit 1.
0: KBRST is not forced active (default)
1: Force KBRST active
1ROHPWRON (Host Power On). The VDD power detection logic indicates that VDD is on.
0: VDD is off (below VDDON)
1: VDD is on (above VDDON)
2ROLPCRSTA (LPC Reset Active). The RESET1 input is active (low).
0: RESET1 is not active (high)
1: RESET1 is active (low)
3 R/W1C VHCFGA (Valid Host Configuration Address). This bit is set by a write to HCFGBAH register, as
detailed in the update sequence in “Host Configuration Address Selection” on page 322. The firmware
can clear the bit by writing 1 to it. This register is used as the address of the Configuration registers
when the PC87591x is set to operate with the internal base address. Writing 0 to this bit is ignored.
This bit can be locked and made read-only by setting HCFGLK (bit 4).
0: Host Configuration Registers base address is not valid and access to this registers by the host is not
enabled (default)
1: Host Configuration Registers base address is specified in HCFGBAH and HCFGBAL registers
4 R/W1S HCFGLK (Host Configuration Address Lock). This bit is cleared during VCC power-up,
WATCHDOG reset or Debugger Interface reset, but is unchanged during other reset events.
When 1 is written to this bit, it becomes read only (i.e., it cannot be cleared by the firmware) and locks
VHCFGA bit, HCFGBAH register and HCFGBAL register, preventing accidental alteration to them.
0: Allows update of the Host Configuration Registers base address (default)
1: Locks the Host Configuration Registers base address
5 R/W1C HSECM (Host Software Event Clear Mode). Controls the clear mode of Host Software Event Status
bit in WK_STS0. This bit is cleared at VCC power-up and RESET1 events.
0: Host Software Event Status bit in WK_STS0 (bit 6) toggles on host writes of 1. MSHES0 bit 6 is set
when WK_STS0 bit 6 changes from 0 to 1 (default).
1: Host Software Event Status bit in WK_STS0 (bit 6) and MSHES0 bit 6 are both cleared by writes of
1 to MSHES0 register
7-6 Reserved.
Host Controller Interface Modules (Continued)
www.national.com 330 Revision1.07
PC87591E/S/L
MSWC Control Status Register 2 (MSWCTL2)
This is a byte-wide read/write register that controls the settings associated with host wake-up and activity. Bits in this register
are cleared by VCC Power-Up and RESET1 resets.
Location: 00 FCC216
Type: Varies per bit
MSWC Control Status Register 3 (MSWCTL3)
This is a byte-wide read/write register that controls the settings associated with host wake-up and activity. The contents of
this register is preserved by VPP and it is reset only on VPP Power-Up reset.
Location: 00 FCC416
Type: R/W
Bit 76543210
Name CFGPSO CFGPBM ACPIS5 ACPIS4 ACPIS3 ACPIS2 ACPIS1 ACPIS0
Reset 00000000
Bit Type Description
0 R/W1C ACPIS0 (ACPI request for S0). This bit may be used by ACPI software to directly request a change of
power state. This bit is set when the host software writes a value of 0 to bits S1 through S5 in
WK_STATE register. This bit is cleared by writing 1 to it. A write of 0 is ignored.
0: No pending request for S0 change (default)
1: A request for S0 change was detected
5-1 R/W1C ACPIS1-5 (ACPI request for S1 through S5). These bits may be used by ACPI software to directly
request a change of power state. These bits are set by a host software write of 1 to the respective bit in
WK_STATE register. The bit is cleared by writing 1 to it. A write of 0 is ignored.
When any ACPIS0 through ACPIS5 bit is set, an APC interrupt to the core, using a MIWU input, is
asserted.
6ROCFGPBM (SuperI/O Configuration Register D Power Button Mode). This bit reflects the current status
of the Power Button Mode bit in SIOCFD register. This bit may be used by the host software to specify
to the core he method used for power off signaling. See “SuperI/O Configuration D Register (SIOCFD)”
on page 347
A write of 1 clears the interrupt signal caused by a change in this bit value. A write of 0 to this bit is
ignored.
7ROCFGPSO (SuperI/O Configuration Register D Power Supply Off). This bit is set whenever a 1 is
written to the Power Supply Off bit in SIOCFD register. This bit may be used by the host software to
specify to the core that the power supply should be turned off, in a non-ACPI system. See “SuperI/O
Configuration D Register (SIOCFD)” on page 347.
A write of 1 clears this bit and the interrupt signal caused by a change in this bit value. A write of 0 to
this bit is ignored.
Bit 76543210
Name Reserved RTCAL LPFTO HRAPU
Reset 00000001
Host Controller Interface Modules (Continued)
Revision 1.07 331 www.national.com
PC87591E/S/L
Host Configuration Base Address Low (HCFGBAL)
This is a byte-wide read/write register that holds the lower byte of the Host Configuration Registers base address. Bit 0 of
this register is always forced to 0 to guarantee address alignment. This register is cleared on VCC Power-Up reset.
Location: 00 FCC816
Type: R/W
Host Configuration Base Address High (HCFGBAH)
This is a byte-wide read/write register that holds the higher byte of the Host Configuration Registers base address. This reg-
ister is cleared on VCC Power-Up reset.
Location: 00 FCCA16
Type: R/W
MSWC Interrupt Enable Register 2 (MSIEN2)
This is a byte-wide read/write register that holds enable bits for interrupt generation to the core through the MIWU (level high)
for the respective bits in MSWCTL2 and MSWCTL3 registers. The interrupt may be cleared by clearing the status bit or
masking the interrupt. On Warm reset, this register is cleared (0016).
Location: 00 FCCC16
Type: R/W
Bit Description
0HRAPU (Host Reset when Accessed During VCC Power-Up Reset). Indicates that a reset should be sent to
the host if LPC activity was detected while the VCC Power-Up reset was not completed. This intends to re-start
any LPC transaction that may have addressed the PC87591x but could not be handled correctly. When
HCFGLK bit is set, writes to this bits are ignored.
0: Do not generate a reset on LPC transactions while the PC87591x is in Power-Up reset
1: Assert KBRST output on LPC transactions while the PC87591x is executing the VCC Power-Up reset sequence
(default)
1LPFTO (LPC Power Fail Turn Off KBRST and GA20). Indicates the handling of KBRST and GA20 outputs
when LPCPD is active.
0: Ignore LPCPD in handling these signals (default)
1: Force the two signals low while LPCPD is active or VDD is low
2RTCAL (RTC Alarm). Indicates that an RTC Alarm event occurred. This bit is set on the rising edge of the RTC
Alarm output. It is cleared by writing 1 to it. Note that the ALARM event detection is edge triggered by the
RTCAL bit; thus for a new event to be detected, first RTCAL bit and then Alarm Status bit in the RTC must be
cleared.
0: No RTC Alarm is flagged (default)
1: RTC Alarm rising edge was detected
7-3 Reserved.
Bit 76543210
Name Host Configuration Registers Base Address Low
Reset 00000000
Bit 76543210
Name Host Configuration Registers Base Address High
Reset 00000000
Host Controller Interface Modules (Continued)
www.national.com 332 Revision1.07
PC87591E/S/L
MSWC Host Event Status Register 0 (MSHES0)
This register holds information similar to that in WK_STS0 register. The same event that causes a WK_STS0 bit to be set
sets the respective bit in MSHES0 register. Clearing bits is done for each of the status registers separately. This register is
reset to 0016 on VCC power-up or Host Domain Software reset. Writing 1 to a bit clears it to 0. Writing 0 has no effect. Bit 6
of this register behaves in a special way on set and clear, as described below.
Location: Offset 00 FCCE16
Type: R/W1C
Bit 76543210
Name EICFGPSO EICFGPBM EIACPIS5 EIACPIS4 EIACPIS3 EIACPIS2 EIACPIS1 EIRTCAL
Reset 00000000
Bit Description
0EIRTCAL (Enable Interrupt on RTC Alarm). Mask generation of interrupt to the core on setting of the RTC
Alarm bit in MSWCTL1 register.
0: Interrupt disabled (default)
1: Generate a level high interrupt when the RTC Alarm bit is set
5-1 EIACPIS5-1 (Enable Interrupt ACPI request for S5 through S1). Mask generation of interrupt to the core on
changes to ACPISi (i=5-1) bit in MSWCTL2 register. An interrupt enable for ACPIS0 is enabled when any of
these bits is set.
0: Interrupt disabled (default)
1: Generate a level high interrupt on any change to the ACPISi bit
6EICFGPBM (Enable Interrupt SuperI/O Configuration Register D Power Button Mode). Mask generation of
interrupt to the core on changes to CFGPBM bit in MSWCTL2 register.
0: Interrupt disabled (default)
1: Generate a level high interrupt on any change to the CFGPBM bit
7EICFGPSO (Enable Interrupt SuperI/O Configuration Register D Power Supply Off). Mask generation of
interrupt to the core on changes to CFGPSO bit in MSWCTL2 register.
0: Interrupt disabled (default)
1: Generate a level high interrupt on any change to the CFGPBM bit
Bit 76543210
Name Module IRQ
Event
Status
Software
Event
Status Reserved RING
Event
Status Reserved RI2
Event
Status
RI1
Event
Status
Reset 00000000
Bit Description
0RI1 Event Status.
0: Event not detected (default)
1: Event detected
1RI2 Event Status.
0: Event not detected (default)
1: Event detected
2Reserved.
Host Controller Interface Modules (Continued)
Revision 1.07 333 www.national.com
PC87591E/S/L
MSWC Host Event Interrupt Enable Register (MSHEIE0)
This register is cleared to 0016 on Warm reset. It enables a core interrupt through the MIWU (level high) for the respective
bit in the mobile MSHES0 register. The interrupt may be cleared by clearing the status bit or masking the interrupt.
Location: Offset 00 FCD016
Type: R/W
3RING Event Status. RING event detection, according to the RING detection mode enabled.
0: Event not detected (default)
1: Event detected
5-4 Reserved.
6Software Event Status. This bit indicates a host software event. It may operate in two modes depending on
HSECM bit in MSWCTL1 register.
When HSECM is cleared, this bit is set when bit 6 of WK_STS0 changes from 0 to 1.
When HSECM is set, this bit is set on a write of 1 to WK_STS0 bit 1.
This bit is cleared by writing 1 to it.
0: Event not active (default)
1: Event active
7Module IRQ Event Status. This sticky bit shows the status of the module IRQ event detection.
0: Event not active (default)
1: Event active
Bit 76543210
Name Module IRQ
Event
Enable
Software
Event
Enable Reserved RING
Event
Enable Reserved RI2
Event
Enable
RI1
Event
Enable
Reset 00000000
Bit Description
0RI1 Event Enable.
0: Disabled (default)
1: Enabled
1RI2 Event Enable.
0: Disabled (default)
1: Enabled
2Reserved.
3RING Event Enable.
0: Disabled (default)
1: Enabled
5-4 Reserved.
6Software Event Enable.
0: Disabled (default)
1: Enabled
7Module IRQ Event Enable.
0: Disabled (default)
1: Enabled
Bit Description
Host Controller Interface Modules (Continued)
www.national.com 334 Revision1.07
PC87591E/S/L
5.5.7 Usage Hints
PWUREQ Output Connection
The PWUREQ concentrates a set of wake-up and other power management events in the PC87591x. In typical use, this
signal is connected to one of the chipset inputs that drive SCI event to the host.
RESET2 Events
When RESET2 is used to reset the host domain, some of the MSWC functions may need to be set to their default values
when a falling edge of the RESET2 is detected. An interrupt routine triggered by this event may be used for this task. The
following functions should be reset:
GA20
KBRST
Host Registers: WK_EN0, WK_SMIEN0 and WK_IRWEN0;
Use the “Core Access to Host-Controlled Modules” for this operation (see Section 5.4 on page 313).
Revision 1.07 335 www.national.com
PC87591E/S/L
6.0 Host-Controlled Modules and Host Interface
6.1 DEVICE ARCHITECTURE AND CONFIGURATION
The PC87591x Host-Controlled Functions comprises a collection of generic and proprietary functional blocks. Each func-
tional block is described in a separate chapter in this document. However, some parameters in the implementation of the
functional blocks may vary per function and/or device. This chapter describes the PC87591x structure and provides all log-
ical device-specific information, including special implementation of generic blocks, system interface and device configura-
tion.
The PC87591x Host-Controlled Functions consist of seven logical devices (involving six modules), the host interface and a
central set of configuration registers, all built around a central internal bus. The internal bus is similar to an 8-bit ISA bus
protocol. Figure 108 illustrates the blocks and their interconnection.
The LPC Bus Interface serves as a bridge between the external LPC interface and the internal bus. It supports the following
operations, as defined in Intel’s LPC Interface Specification, Revision 1.0:
8-bit I/O read
8-bit I/O write
8-bit Memory read
8-bit Memory write
8-bit FWH read
8-bit FWH write
The Configuration and Control register set supports ACPI-compliant PnP configuration. The configuration registers are
structured as a subset of the Plug and Play Standard registers, defined in Appendix A of the Plug and Play ISA Specification,
Revision 1.0a by Intel and Microsoft, and are similar to those used in National SuperI/O devices. All system resources as-
signed to the functional blocks (I/O address space, and IRQ lines) are configured in and managed by this register set. In
addition, some function-specific parameters are configurable through the configuration registers and distributed to the func-
tional blocks through special control signals.
6.1.1 Configuration Structure and Access
The configuration structure comprises a set of banked registers that are accessed via a pair of specialized registers.
The Index-Data Register Pair
Access to the Host-Controlled Functions configuration registers is via an Index-Data register pair, using two system I/O byte
locations. The base address of this register pair is determined during VCC Power-Up reset, according to the state of the hard-
ware strapping option on the BADDR1-0 pins. Table 47 shows the selected base addresses as a function of BADDR1-0 (see
Section 2.2.11 on page 50).
Table 47. BADDR1-0 Strapping Options
The Index register is an 8-bit read/write register located at the selected base address (Base+0). It is used as a pointer to the
configuration register file and holds the index of the configuration register that is currently accessible via the Data register.
Reading the Index register returns the last value written to it (or a default of 0016 after Host Domain reset).
The Data register is an 8-bit register located at the selected base address (Base+1) used as a data path to any configuration
register. Accessing the Data register actually accesses the configuration register that the Index register is currently pointed
to.
BADDR1-0 I/O Address
Index Register Data Register
00 2E
16 2F16
01 4E
16 4F16
10
1
1. See “Host Configuration Address Selection” on page 322 for more
details about this option.
(HCFGBAH,HCFGBAL) (HCFGBAH,HCFGBAL)+1
1 1 Reserved
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 336 Revision1.07
PC87591E/S/L
Figure 108. Host-Controlled Domain Detailed Block Diagram
Banked Logical Device Registers Structure
Each functional block is associated with a Logical Device Number (LDN). The configuration registers are grouped into banks,
where each bank holds the standard configuration registers of the corresponding logical device. Table 48 shows the LDN
values of the PC87591x functional blocks. Any value not listed is reserved.
Figure 109 shows the structure of the standard configuration register file. The Host-Controlled Functions control and config-
uration registers are not banked and are accessed by the Index-Data register pair only, as described above. However, the
device control and device configuration registers are duplicated over seven banks for the seven logical devices. Therefore,
two-dimensional indexing is used to access a specific register in a specific bank: the LDN register selects the bank (or logical
device) and the Index register selects the register within the bank. Accessing the Data register while the Index register holds
a value of 3016 or higher physically accesses the logical device configuration registers currently pointed to by the Index reg-
ister, within the logical device currently selected by the LDN register.
Internal Bus
LPC
Control Signals
Interface
LCLK
RESET1-2
LAD3-0
LFRAME
LDRQ
SERIRQ
RI1
RI2
SMI
BADDR0-1
& Control
Registers
Config
Shared
Strap
Config
CLKRUN
LPCPD
Bus
RTC
BIOS
&
Security
System
Wake-Up
Control
Mobile
Peripheral Bus
Core Bus
SHBM
HCFGBAH, HCFGBAL
KBC
&
PM
Host I/F
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 337 www.national.com
PC87591E/S/L
Figure 109. Structure of Standard Configuration Register File
Table 48. Logical Device Number (LDN) Assignments
Write accesses to unimplemented registers (i.e., accessing the Data register while the Index register points to a non-existing
register) are ignored; reads return 0016 for all addresses except 7416 and 7516 (DMA configuration registers), which return 0416
(indicating that no DMA channel is active). The configuration registers are accessible immediately after Host Domain reset.
Standard Logical Device Configuration Register Definitions
In the registers below, any undefined bit is reserved. Unless otherwise noted, the following definitions also hold true:
All registers are read/write.
All reserved bits return 0 on reads except where noted. To prevent unpredictable results, do not modify these bits.
Use read-modify-write to prevent the values of reserved bits from being changed during write.
Write-only registers should not use read-modify-write during updates.
LDN Functional Block
0416 Mobile System Wake-Up Control (MSWC)
0516 Keyboard and Mouse Controller (KBC) - Mouse Interface
0616 Keyboard and Mouse Controller (KBC) - Keyboard Interface
0F16 Shared BIOS and Security
1016 Real Time Clock
1116 Power Management I/F Channel 1
1216 Power Management I/F Channel 2
0716
2016
3016
6016
7516
FE16
Logical Device Number Register
SuperI/O Configuration Registers
Logical Device Control Register
Standard Logical Device
Special (Vendor-Defined)
Configuration Registers
Banks
2F16
F016 Bank Select
6316
7416
7016
7116 Configuration Registers
(One per Logical Device)
Logical Device
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 338 Revision1.07
PC87591E/S/L
Table 49. Standard Control Registers
Table 50. Logical Device Activate Register
Table 51. I/O Space Configuration Registers
Index Register Name Description
0716 Logical Device
Number This register selects the current logical device. See Table 48 for valid numbers. All
other values are reserved.
2016 -2F
16 SuperI/O
Configuration SuperI/O configuration registers and ID registers
Index Register Name Description
3016 Activate Bits 7-1: Reserved
Bit 0: Logical device activation control
0: Disabled
1: Enabled
Index Register Name Description
6016 I/O Port Base
Address Bits (15-8)
Descriptor 0
Indicates selected I/O lower limit address bits 15-8 for I/O Descriptor 0.
6116 I/O Port Base
Address Bits (7-0)
Descriptor 0
Indicates selected I/O lower limit address bits 7-0 for I/O Descriptor 0.
6216 I/O Port Base
Address Bits (15-8)
Descriptor 1
Indicates selected I/O group 2 lower limit address bits 15-8 for I/O Descriptor 1.
6316 I/O Port Base
Address Bits (7-0)
Descriptor 1
Indicates selected I/O group 2 lower limit address bits 7-0 for I/O Descriptor 1.
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 339 www.national.com
PC87591E/S/L
Table 52. Interrupt Configuration Registers
Table 53. DMA Configuration Registers
Table 54. Special Logical Device Configuration Registers
Index Register Name Description
7016 Interrupt Number
and Wake-Up on
IRQ Enable
Indicates selected interrupt number.
Bits 7-5: Reserved.
Bit 4: Enables wake-up on the IRQ of the logical device. When enabled, IRQ as-
sertion triggers a wake-up event.
0: Disabled (default)
1: Enabled
Bits 3-0: select the interrupt number. A value of 1 selects IRQ1, a value of 2 selects
IRQ2, etc. (up to IRQ15). A value of 0 disables this interrupt.
7116 Interrupt Request
Type Select Indicates the type and level of the interrupt request number selected in the previous
register.
Bits 7-2: Reserved.
Bit 1: Polarity of interrupt request selected in previous register
0: Low polarity
1: High polarity
Bit 0: Type of interrupt request selected in previous register
0: Edge
1: Level
Index Register Name Description
7416 DMA Channel
Select 0 Indicates selected DMA channel for DMA 0 of the logical device (0: The first DMA
channel if more than one DMA channel is used).
Bits 7-3: Reserved.
Bits 2-0: Select the DMA channel for DMA 0. The valid choices are 0-3, where:
A value of 0 selects DMA channel 0, 1 selects channel 1, etc.
A value of 4 indicates that no DMA channel is active.
The values 5-7 are reserved.
7516 DMA Channel
Select 1 Indicates selected DMA channel for DMA 1 of the logical device (1: The second
DMA channel if more than one DMA channel is used).
Bits 7-3: Reserved.
Bits 2-0: Select the DMA channel for DMA 1. The valid choices are 0-3, where:
A value of 0 selects DMA channel 0, 1 selects channel 1, etc.
A value of 4 indicates that no DMA channel is active.
The values 5-7 are reserved.
Index Register Name Description
F016-FE16 Logical Device
Configuration Special (vendor-defined) configuration options
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 340 Revision1.07
PC87591E/S/L
6.1.2 Standard Configuration Registers
SuperI/O Control and Configuration Registers
The SuperI/O configuration registers at indexes 2016 and 2716 are mainly used for part identification, global power manage-
ment and the selection of pin multiplexing options. For details, see Section 6.1.8 on page 343.
Logical Device Control and Configuration Registers
A subset of these registers is implemented for each logical device. See the functional block descriptions in Chapter 5 on
page 277 and Chapter 6 on page 335.
Control
The only implemented control register for each logical device is the Activate register at index 3016. Bit 0 of Activate register
controls the activation of the associated functional block. Activation enables access to the functional block’s registers and
attaches the functional block’s system resources (e.g., address space and interrupts), which are unused as long as the block
is not activated. Other effects may apply on a function-specific basis (such as clock enable and active pinout signaling).
SuperI/O Control and
Configuration Registers
Logical Device Control and
one per Logical Device
Configuration Registers -
Index Register Name
0716 Logical Device Number
2016 SuperI/O ID
2116 SuperI/O Configuration 1
2516 SuperI/O Configuration 5
2616 SuperI/O Configuration 6
2716 SuperI/O Revision ID
2816 SuperI/O Configuration 8
2916 SuperI/O Configuration 9
2D16 SuperI/O Configuration D
2B16 -2E
16 Reserved exclusively for National use
3016 Logical Device Control (Activate)
6016 I/O Base Address Descriptor 0 Bits 15-8
6116 I/O Base Address Descriptor 0 Bits 7-0
6216 I/O Base Address Descriptor 1 Bits 15-8
6316 I/O Base Address Descriptor 1 Bits 7-0
7016 Interrupt Number and Wake-Up on IRQ Enable
7116 IRQ Type Select
7416 DMA Channel Select 0
7516 DMA Channel Select 1
F016 -F9
16 Device Specific Logical Device Configuration 1 to 10
(some are optional)
Figure 110. Configuration Register Map
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 341 www.national.com
PC87591E/S/L
Standard Configuration
The standard configuration registers manage the PnP resource allocation to the functional blocks. The I/O port base address
(descriptor 0) is a pair of registers at index 60-6116, holding the first 16-bit base address for the register set of the functional
block. An optional 16-bit second base-address (descriptor 1) at index 62-6316 is used for logical devices with more than one
continuous register set. Interrupt Number and Wake-Up on IRQ Enable (index 7016) and IRQ Type Select (index 7116) reg-
isters allocate an IRQ number to the module’s interrupt and control the interrupt type and polarity. DMA Channel Select 0
(index 7416) allocates a DMA channel to the block, where applicable. DMA Channel Select 1 (index 7516) allocates a second
DMA channel, where applicable.
Special Configuration
The vendor-defined registers, starting at index F016 -F9
16, control function-specific parameters such as operation modes,
power saving modes, clock rate selection and non-standard extensions to generic functions.
6.1.3 Default Configuration Setup
The default configuration setup of the PC87591x Host-Controlled functions is set according to the following reset types (see
Section 3.2 on page 65):
VPP Power-Up Reset
Resets VPP-retained SuperI/O functions, such as the RTC and the MSWC registers, whose values are retained by
VPP
.
VCC Power-Up Reset
Resets the MSWC registers whose values are retained by VCC only.
Host Domain Hardware Reset
Resets all SuperI/O logical devices, with the exception of the Mobile System Wake-Up Control (MSWC) and the RTC
registers retained by VPP or VCC.
Resets all SuperI/O configuration registers.
Host Domain Software Reset
Resets all SuperI/O logical devices, except the MSWC and the RTC registers retained by VPP or VCC.
Resets most bits in the SuperI/O configuration registers. This reset does not affect register bits that are locked for
write access (see “SuperI/O Configuration 6 Register (SIOCF6)” on page 345 and Table 47 on page 335).
If a Host Domain Hardware reset occurs, the PC87591x wakes up with the following default SuperI/O configuration setup:
The configuration base address is according to the BADDR strap pin value, as shown in Table 47 on page 335.
All logical devices are disabled, with the exception of the MSWC and shared memory, which remain functional but
whose registers cannot be accessed.
If a Host Domain reset occurs (either Software or Hardware), the PC87591x wakes up with the following default SuperI/O
configuration setup:
The legacy devices are assigned with their legacy system resource allocation.
The National proprietary functions are not assigned with any default resources, and the default values of their base
addresses are all 0016.
6.1.4 Address Decoding
A full 16-bit address decoding is applied when accessing the configuration I/O space as well as the registers of the functional
blocks. However, the number of configurable bits in the base address registers varies for each logical device.
The lower 0, 1, 2, 3, 4 or 5 address bits are decoded within the functional block to determine the offset of the accessed reg-
ister within the logical device’s I/O range of 1, 2, 4, 8, 16 or 32 bytes, respectively. The rest of the bits are matched with the
base address register to decode the entire I/O range allocated to the logical device. Therefore, the lower bits of the base
address register are forced to 0 (read only), and the base address is forced to be 1, 2, 4, 8, 16 or 32 byte-aligned, according
to the size of the I/O range.
The base address of the KBC, PM channel 1 and PM channel 2 are limited to the I/O address range of 000016 to 07FX16
only (bits 11-15 are forced to 0). The addresses of other devices are configurable within the full 16-bit address range (up to
FFFF16).
In some special cases, other address bits are used for internal decoding (such as bit 2 in the KBC). The KBC has two I/O
descriptors with some implied dependency between them. For more details, see the description of the base address register
for each logical device.
The Shared Memory and Security module serves as a bridge from the LPC to the on-chip flash and off-chip expansion mem-
ory. For module control and security function registers, the 16-bit base address is applied through the configuration address
space. To access the registers, the lower four address bits are decoded within the Shared Memory module. The address
ranges in the LPC memory space and the FWH memory space, which are bridged to the shared memory, are defined in the
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 342 Revision1.07
PC87591E/S/L
SuperI/O configuration section for the shared memory bridge. The number of address bits used for this decoding varies ac-
cording to the specified zones and their sizes. See “Memory Range Programing” on page 350 and “Shared Memory Config-
uration Register” on page 351 for details about the address range specifications.
6.1.5 Interrupt Serializer
The Interrupt Serializer translates internal IRQ sources into serial interrupt request data transmitted over the SERIRQ bus.
Figure 111 shows the interrupt serialization mechanism.
Figure 111. Interrupt Serialization Mechanism
The internal IRQ signals are fed into an IRQ Mapping and Polarity Control block. This block maps them to their associated
IRQ slots. The IRQs are then fed into the Interrupt Serializer, where they are translated into serial data and transmitted over
the SERIRQ bus.
6.1.6 Protection
The PC87591x provides features to protect the Personal Computer (PC) at software levels. The PC can be locked to protect
configuration bits and to prevent alteration of the device hardware configuration and several types of configuration settings.
The use of all protection mechanisms is optional.
6.1.7 LPC Interface
LPC Transactions Supported
The PC87591x LPC interface responds to the following LPC transactions as part of the standard Host Bus interface:
I/O read cycles
I/O write cycles
In addition, the Shared Memory module uses the following transactions:
8-bit memory read and write
8-bit FWH read and write
LPC transactions conform with Intel’s LPC Interface Specification, Revision 1.0.
The LPC- FWH read and write protocols are similar to memory read and write cycles. The specifications of these cycles are
listed below. The Address, Data, TAR and SYNC cycles are as specified for LPC memory read and write cycles. The START
and ID fields are similar to the equivalent cycle in LPC memory read and write transactions but differ in the data placed on
the LAD signals (see details in the cycle description).
Note: The PC87591x supports FWH transactions from LPC controllers that accept wait-sync and long wait-sync cycles. With
other LPC controllers, use the indirect write mechanism in the Shared Memory module to perform write operations.
FWH Read Cycle
1. START: 110116 (0xD).
2. ID field: FWH ID nibble (compared with bits 7-4 of shared memory; see “Shared Memory Configuration Register” on
page 351).
3. Address: Eight address nibbles, MS nibble first; see usage below).
4. TAR (two cycles).
5. SYNC.
6. DATA: Two data nibbles, LS nibble first (D3-D0, D7-D4).
7. TAR (two cycles).
IRQ Mapping,
Enable and Polarity
Control
Internal
IRQ
Sources
Control
Signals
Interrupt
Serializer
LPC Interface
SERIRQ
IRQ1
IRQ15
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 343 www.national.com
PC87591E/S/L
FWH Write Cycle:
1. START: 111016 (0xE).
2. ID field: FWH ID nibble (compared with bits 7-4 of shared memory; see “Shared Memory Configuration Register” on
page 351).
3. Address: Eight address nibbles MS nibble first (see usage below).
4. DATA: Two data nibbles, LS nibble first (D3-D0, D7-D4).
5. TAR (two cycles).
6. SYNC.
7. TAR (two cycles).
The ID field is compared with bits 7-4 of shared memory; see “Shared Memory Configuration Register” on page 351. If the
two match, the PC87591x continues handling the transaction; if they do not match, the current LPC-FWH transaction is ig-
nored.
LPC-FWH Address translation: The address field in the LPC-FWH transaction is constructed of eight nibbles. The first seven
correspond to the first LS seven address nibbles (A27-A0) as follows: The first nibble that appears corresponds to addresses
A27-A24, the second to A23-A20, until the seventh incoming nibble, which corresponds to addresses A3-A0. Incoming nib-
ble number eight is ignored. The MS bits of the 32-bit addresses are ‘1111’ (A31 - A28).
Core Interrupt
Whenever there is an LPC or FWH transaction that is responded to by any of the PC87591x logical devices, a positive pulse
is generated on the Host Access Wake-Up input of the MIWU module. This interrupt may be used to wake up the core for
handling any host activity.
CLKRUN Functionality
The PC87591x supports the CLKRUN I/O signal, the use of which is highly recommended in portable systems. This signal
is implemented according to the specification in PCI Mobile Design Guide, Revision 1.1, December 18, 1998. The PC87591x
supports operation with both a slow and stopped clock in ACPI state S0 (the system is active but is not being accessed).
The PC87591x drives the CLKRUN low to force the LPC bus clock into full speed operation when an IRQ is pending inter-
nally and waiting to be sent through the serial IRQ.
LPCPD Functionality
The PC87591x supports the LPCPD input. This signal is used when the VDD chip supply is not shared by all residents of the
LPC bus. The LPCPD signal conforms with Intel’s LPC Interface Specification, Revision 1.0. Note that if the PC87591x pow-
er supply exists while LPCPD is active, it is not mandatory to reset the PC87591x when LPCPD is de-asserted.
6.1.8 SuperI/O Configuration Registers
This section describes the SuperI/O configuration and ID registers (those registers with first level indexes in the range of
2016 - 2E16). See Table 55 for a summary and directory of these registers.
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
Table 55. SuperI/O Configuration Registers
Index Mnemonic Register Name Power Well Type
2016 SID SuperI/O ID VDD RO
2116 SIOCF1 SuperI/O Configuration 1 VDD Varies per bit
2216 -24
16 Reserved exclusively for National use
2516 SIOCF5 SuperI/O Configuration 5 VDD R/W
2616 SIOCF6 SuperI/O Configuration 6 VDD R/W
2716 SRID SuperI/O Revision ID VDD RO
2816 SIOCF8 SuperI/O Configuration 8 VDD R/W
2916 SIOCF9 SuperI/O Configuration 9 VDD R/W
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 344 Revision1.07
PC87591E/S/L
SuperI/O ID Register (SID)
This register contains the identity number of the chip. The PC87591x is identified by the value EC16.
Location: Index 2016
Type: RO
SuperI/O Configuration 1 Register (SIOCF1)
Location: Index 2116
Type: Varies per bit
2A16 -2C
16 Reserved exclusively for National use
2D16 SIOCFD SuperI/O Configuration D VPP R/W
2E16 Reserved exclusively for National use
Bit 76543210
Name Family ID
Reset EC16
Bit Description
7-0 Family ID. These bits identify a family of devices with similar functionality but with different options
implemented.
Bit 76543210
Name Reserved Number of DMA Wait
States Number of I/O Wait
States Software
Reset
SuperI/O
Devices
Enable
Reset 00010001
Bit Type Description
0 R/W SuperI/O Devices Enable. Controls the function enable of all the PC87591x SuperI/O logical devices,
except shared memory and Mobile System Wake-Up Control (MSWC). This bit enables the
simultaneous disabling of these modules using a write to a single bit.
0: All SuperI/O logical devices in the PC87591x are disabled, except MSWC and shared memory
1: Each SuperI/O logical device is enabled according to its Activate register (Index 3016) (default)
1WOSoftware Reset. Read always returns 0.
0: Ignored (default)
1: Triggers the Host Domain Software Reset event, which resets the logical devices (see Section 6.1.3
on page 341)
3-2 R/W Number of I/O Wait States.
Bits
3 2 Number
0 0: 0 (default)
0 1: 2
1 0: 6
1 1: 12
Table 55. SuperI/O Configuration Registers (Continued)
Index Mnemonic Register Name Power Well Type
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 345 www.national.com
PC87591E/S/L
SuperI/O Configuration 5 Register (SIOCF5)
Location: Index 2516
Type: R/W
SuperI/O Configuration 6 Register (SIOCF6)
Write access to this register can be inhibited by setting bit 7 of this register. Activation of each logical device (bits 0-4) is also
affected by bit 0 of the logical device Activate register, index 3016, and bit 0 of SIOCF1 register.
Location: Index 2616
Type: R/W
5-4 R/W Number of DMA Wait States.
Bits
5 4 Number
0 0: Reserved
0 1: 2 (default)
1 0: 6
1 1: 12
7-6 Reserved.
Bit 76543210
Name Reserved SMI to IRQ2
Enable Reserved
Reset 00000000
Bit Type Description
3-0 Reserved.
4 R/W SMI to IRQ2 Enable. Enables using slot number 2 in the serial IRQ protocol as an SMI interrupt in
parallel to or instead of using the dedicated pin.
0: Disabled (default)
1: Enabled
7-5 Reserved.
Bit 76543210
Name SIOCF6
Software
Lock
General-Purpose
Scratch RTC
Disabled Reserved
Reset 00000000
Bit Description
3-0 Reserved.
Bit Type Description
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 346 Revision1.07
PC87591E/S/L
SuperI/O Revision ID Register (SRID)
This register contains the ID number of the specific family member (Chip ID) and the chip revision number (Chip Rev). The
Chip Rev is incremented on each revision.
Location: Index 2716
Type: RO
SuperI/O Configuration 8 Register (SIOCF8)
Location: Index 2816
Type: R/W
4RTC Disabled.
0: Enabled (default)
1: Disabled
6-5 General-Purpose Scratch.
7SIOCF6 Software Lock. When set to 1 by software, it and other bits in this register can be cleared only by Host
Domain Hardware reset.
0: Write access to bits 0-6 of this register enabled (default)
1: Bits 6-0 of this register are read only.
Bit 76543210
Name Chip ID Chip Rev
Reset See values in field description XXXXX
Bit Description
4-0 Chip Rev. Identifies the device revision.
7-5 Chip ID. Identifies a specific device of the PC87591x family.
Bits
7 6 5 Device
0 0 0: PC87591E
0 0 1: PC87591S
1 0 0: PC87591 L
Other: Reserved
Bit 76543210
Name Reserved
Reset 0 0 0 00000
Bit Description
7-0 Reserved.
Bit Description
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 347 www.national.com
PC87591E/S/L
SuperI/O Configuration 9 Register (SIOCF9)
Location: Index 2916
Type: R/W
SuperI/O Configuration D Register (SIOCFD)
This is a battery-backed register.
Location: Index 2D16
Type: R/W
Bit 76543210
Name Reserved Reserved
Reset 0 0 0 00001
Bit Description
7-0 Reserved.
Bit 76543210
Name Reserved Power
Supply Off
Power
Button
Mode
Reset 00000000
Bit Description
0Power Button Mode. This is a R/W bit. The value of this bit is available to the core through a register in the
MSWC; see Section 5.5 on page 318.
0: Legacy (default at VCC Power-Up reset)
1: ACPI
1Power Supply Off. This is a R/W bit. It always returns 0 when read. When using Legacy mode (bit 0 is set to
0) and setting this bit to 1, this bit indicates to the core that the host requests shutting down the power. The
value of this bit is available to the core by reading a register in the MSWC; see Section 5.5 on page 318.
0: No action (default at VPP Power-Up reset)
1: Indicates power shut down to the core in Legacy mode
7-2 Reserved.
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 348 Revision1.07
PC87591E/S/L
6.1.9 Mobile System Wake-Up Control (MSWC) Configuration
Logical Device 4 (MSWC) Configuration
Table 56 lists the configuration registers that affect the MSWC. See Section 6.1.2 on page 340 for a detailed description of
these registers.
Table 56. Mobile System Wake-Up Control (MSWC) Configuration Registers
6.1.10 Keyboard and Mouse Controller (KBC) Configuration
Logical Devices 5 and 6 (Mouse and Keyboard) Configuration
Tables 57 and 58 list the configuration registers that affect the Mouse and the Keyboard respectively. Only the last register
(F016) is described here. See “Standard Logical Device Configuration Register Definitions” on page 337 and Section 6.1.2
on page 340 for descriptions of the other configuration registers.
Usage Hints: It is recommended to set the type of interrupt request as level and its level of interrupt as high.
Table 57. Mouse Configuration Registers
Index Configuration Register or Action Type Reset
3016 Activate. When bit 0 is cleared, the registers of this logical device are not
accessible.1
1. The logical device registers are maintained, and all wake-up detection mechanisms are functional.
R/W 0016
6016 Base Address MSB register. R/W 0016
6116 Base Address LSB register. Bits 4-0 (for A4-0) are read only, ‘00000’. R/W 0016
7016 Interrupt Number. R/W 0016
7116 Interrupt Type. Bit 1 is read/write. Other bits are read only. R/W 0316
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
Index Mouse Configuration Register or Action Type Reset
3016 Activate. See also bit 0 of the SIOCF1. When the Mouse of the KBC is inactive,
the IRQ selected by the Mouse Interrupt Number and Wake-Up on IRQ Enable
register (index 7016) is not asserted. This register has no effect on host KBC
commands handling the PS/2 Mouse.
R/W 0016
7016 Mouse Interrupt Number and Wake-Up on IRQ Enable register. R/W 0C16
7116 Mouse Interrupt Type. Bit 1 is read/write; other bits are read only. R/W 0316
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 349 www.national.com
PC87591E/S/L
Table 58. Keyboard Configuration Registers
6.1.11 Shared Memory Configuration
Logical Device 15 (0F16) (Shared Memory) Configuration
Table 59 lists the configuration registers that affect the shared memory functional block. The shared memory base address
registerspointtothesharedmemoryregistersdescribedinSection 5.3onpage 297.Thememoryspacetowhich the shared
memory responds is defined by the configuration registers in the following sections. See “Standard Logical Device Config-
uration Register Definitions” on page 337 and Section 6.1.2 on page 340 for a detailed description of the other configuration
registers.
Table 59. Shared Memory Configuration Registers
Index Keyboard Configuration Register or Action Type Reset
3016 Activate. See also bit 0 of the SIOCF1. R/W 0016
6016 Base Address MSB register. Bits 7-3 (for A15-11) are read only, ‘00000’. R/W 0016
6116 Base Address LSB register. Bits 2-0 are read only, ‘000’. R/W 6016
6216 Command Base Address MSB register. Bits 7-3 (for A15-11) are read only,
‘00000’. R/W 0016
6316 Command Base Address LSB. Bits 2-0 are read only, ‘100’. R/W 6416
7016 KBD Interrupt Number and Wake-Up on IRQ Enable register. R/W 0116
7116 KBD Interrupt Type. Bit 1 is read/write; other bits are read only. R/W 0316
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
Index Configuration Register or Action Type Reset
3016 Activate. When bit 0 is cleared, the registers of this logical device are not
accessible. R/W 0016
6016 Base Address MSB register. R/W 0016
6116 Base Address LSB register. Bits 3-0 (for A3-A0) are read only, ‘0000’. R/W 0016
7016 No interrupt assignment. RO 0016
7116 No interrupt assignment. RO 0016
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
F416 Shared Memory Configuration register. R/W 0016 or 0916, de-
pending on the
value of the
SHBM strap input
F516 Shared Memory Base Address High Byte register. R/W 0016
F616 Shared Memory Base Address Low Byte register. R/W 0016
F716 Shared Memory Size Configuration register. R/W 0016
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 350 Revision1.07
PC87591E/S/L
Memory Range Programing
LPC memory transactions and/or LPC-FWH transactions can be forwarded to the PC87591x shared memory. The Shared
Memory Configuration register defines the transaction type and address range to which the PC87591x responds. The SHBM
strap inputs affect the default settings of the Shared Memory Configuration register to enable boot process from shared
memories. Two memory areas may be individually enabled: a user-defined zone and BIOS memory (either BIOS-LPC
and/or BIOS-FWH spaces).
To enable BIOS support, set the SHBM strap inputs to select any of the BIOS modes (see Section 2.3 on page 53 for de-
tails). The PC87591x responds to LPC memory read and write transactions to/from the BIOS address spaces, shown in
Table 60, as long as BIOS LPC Enable (bit 0) of the Shared Memory Configuration register is set.
Table 60. BIOS-LPC Memory Space Definition
The PC87591x responds to LPC-FWH read and write transactions to/from the high memory address range (’386’ mode
BIOS range), shown in Table 60, as long as BIOS FWH Enable (bit 3) of the Shared Memory Configuration register is set.
Table 61. BIOS-FWH Memory Space Definition
On host domain hardware reset in BIOS mode, the BIOS LPC Enable bit is set and the BIOS FWH Enable bit is set. The
PC87591x automatically detects the type of host boot protocol in use, via the first completed BIOS read operation after host
domain hardware reset. If the first read is an LPC memory read, the BIOS FWH Enable bit is cleared. If the first read is an
LPC-FWH read, the BIOS LPC Enable bit is cleared. Any other LPC or LPC-FWH transactions are ignored. The bits are
cleared only by the first read operation, allowing software to enable responding to these address ranges by setting the bit.
Figure 112 illustrates this behavior.
Figure 112. BIOS Mapping Enable Scheme
Theuser-definedsharedmemoryenablessharingthememorywithout using it as a shared BIOS memory. The memory base
address in the host address space and the size of the shared memory are defined in the Shared Memory Base and Shared
Memory Size registers. Address bits above the block size are ignored and are internally replaced with 1s for the purpose of
address translation (e.g., for a 2 Mbyte block size, A21 through A31 are replaced with 1s).
Memory Address Range Description
000E 000016 - 000E FFFF16 Extended BIOS range (Legacy); only when Extended
BIOS Enable bit in Shared Memory Range Configuration
register is set.
000F 000016 - 000F FFFF16 BIOS Range (Legacy)
FFE0 000016 - FFFF FFFF16 386 mode BIOS range; this is the upper 2 Mbytes of the
memory space.
Memory Address Range Description
FFE0 000016 - FFFF FFFF16 386 mode BIOS range; this is the upper 2 Mbytes of the
memory space. The PC87591x uses the first 21 address
lines and ID field to identify FWH access to the shared
memory.
Note: Only hardware-controlled transitions are shown;
other transitions are possible via software writes to the bits.
BIOS FWH Enable = 1
BIOS LPC Enable = 1
BIOS FWH Enable = 1
BIOS LPC Enable = 0
BIOS FWH Enable = 0
BIOS LPC Enable = 1
BIOS FWH Enable = 0
BIOS LPC Enable = 0
First LPC FWH Read
Host Domain [SHBM = 0] Shared Disable BIOS
[SHBM = 1] Enable BIOS
First LPC Memory Read
Hardware Reset
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 351 www.national.com
PC87591E/S/L
Shared Memory Configuration Register
This register is reset on host domain hardware reset to 0016 or 0916, depending on the value of the SHBM strap input.
Location: Index F416
Type: R/W
Shared Memory Base Address High Byte Register
This register describes the high byte for the user-defined memory zone mapped to the shared memory (decoded as bits 31
to 24 of the 32-bit address range, bits 15-0 are 0). This register is reset to 0016 on Host Domain Hardware reset.
Location: Index F516
Type: R/W
Bit 76543210
Name
BIOS FWH ID BIOS FWH
Enable
User-
Defined
Memory
Space
Enable
BIOS
Extended
Space
Enable
BIOS LPC
Enable
Reset 0000Strap00Strap
Bit Description
0BIOS LPC Enable. Enables the PC87591x to respond to LPC memory accesses to the BIOS-LPC space. The
reset value of this register is defined by the SHBM configuration inputs. The value of this bit is updated later,
based on the detected host BIOS scheme; see “Memory Range Programing” on page 350 for details.
0: Disabled (default when SHBM disable BIOS configuration)
1: Enabled (default when SHBM enable BIOS configuration)
1BIOS Extended Space Enable. Expands the BIOS address space to which the PC87591x responds to include
the Extended BIOS address range.
0: Disabled (default)
1: Enabled
2User-Defined Memory Space Enable. When set, enables the PC87591x to respond to LPC memory read and
write accesses in the user-defined memory area range. The base address and size of the user-defined range
are specified by the Shared Memory Base Address High and Low Byte registers and the Shared Memory Size
Configuration register.
0: Disabled (default)
1: Enabled
3BIOS FWH Enable. When set, enables PC87591x response to LPC-FWH transactions to the BIOS-FWH
space. The reset value of this register is defined by the XCNF(2-0) configuration inputs. The value of this bit is
later updated based on the detected host BIOS scheme; see “Memory Range Programing” on page 350 for
details.
0: Disabled (default when SHBM disable BIOS configuration)
1: Enabled (default when SHBM enable BIOS configuration)
7-4 BIOS FWH ID. These four bits correspond to the identification nibble, which is part of a FWH transaction (see
Section 6.1.7 for details).
Bit 76543210
Name User-Defined Memory Zone Address High
Reset 00000000
Bit Description
7-0 User-Defined Memory Zone Address High. Defines the higher eight bits of the user-defined memory block
base address. The base address should be aligned on the selected block size.
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 352 Revision1.07
PC87591E/S/L
Shared Memory Base Address Low Byte Register
This register describes the low byte for the user-defined memory zone mapped to the shared memory (decoded as bits 23
to 16 of the 32-bit address range, bits 15-0 are 0). This register is reset to 0016 on Host Domain Hardware reset.
Location: Index F616
Type: R/W
Shared Memory Size Configuration Register
This register defines the size of the user-defined memory zone mapped to the shared memory. This register is reset to 0016
on host domain hardware reset.
Location: Index F716
Type: R/W
Bit 76543210
Name User-Defined Memory Zone Address Low
Reset 00000000
Bit Description
7-0 User-Defined Memory Zone Address Low. Defines the lower eight bits of the user-defined memory block base
address. The base address should be aligned on the selected block size.
Bit 76543210
Name Reserved User-Defined Memory Zone Size
Reset 00000000
Bit Description
3-0 User-Defined Memory Zone Size. Defines the size, in bytes, of the zone window. The size is defined as an
exponent of two, using the equation: NumOfBytes = 2n(where, n = User-Defined Memory Zone size+16). The
zone must always be aligned to the window size (i.e., for a 128 Kbyte window, the 17 LSBs of the address
should be zero).
Bits
3 2 1 0 Size (Bytes)
0 0 0 0 64K (default)
. . .
0 1 0 1 2M
Other Reserved
7-4 Reserved.
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 353 www.national.com
PC87591E/S/L
6.1.12 Real Time Clock (RTC) Configuration
Logical Device 16 (1016) RTC Configuration
Table 62 lists the configuration registers that affect the RTC. See Section 6.1.1 on page 335 and Section 6.1.2 on page 340
for descriptions of the other configuration registers.
Table 62. RTC Configuration Registers
RAM Lock Register (RLR)
When a non-reserved bit is set to 1, it can be cleared only by host domain hardware reset.
Location: Index F016
Type: R/W
Index RTC Configuration Register or Action Type Reset
3016 Activate. When bit 0 is cleared, the registers of this logical device are not
accessible. R/W 0016
6016 Base Address MSB register. R/W 0016
6116 Base Address LSB register. Bit 0 (for A0) is read only, ‘0’. R/W 7016
6216 Base Address MSB register. R/W 0016
6316 Base Address LSB register. Bit 0 (for A0) is read only, ‘0’. R/W 7216
7016 RTC Interrupt Number and Wake-Up on IRQ Enable register. R/W 0816
7116 RTC Interrupt Type. Bit 1 is read/write; other bits are read only. R/W 0016
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
F016 RAM Lock Register (RLR) R/W 0016
F116 Date of Month Alarm Register Offset (DOMAO) R/W 0016
F216 Month Alarm Register Offset (MONAO) R/W 0016
F316 Century Register Offset (CENO) R/W 0016
Bit 76543210
Name Block
Standard
RAM
Block RAM
Write
Block
Extended
RAM Write
Block
Extended
RAM Read
Block
Extended
RAM Reserved
Reset 00000000
Bit Description
2-0 Reserved.
3Block Extended RAM. Controls access to the Extended RAM 128 bytes.
0: No effect on Extended RAM access (default)
1: Reads and writes to the Extended RAM are blocked, writes are ignored and reads return FF16
4Block Extended RAM Read. Controls read from bytes 0016-1F16 of the Extended RAM.
0: No effect on Extended RAM access (default)
1: Reads to bytes 0016-1F16 of the Extended RAM are ignored; reads return FF16
5Block Extended RAM Write. Controls writes to bytes 0016-1F16 of the Extended RAM.
0: No effect on the Extended RAM access (default)
1: Writes to bytes 0016-1F16 of the Extended RAM are ignored
6.0 Host-Controlled Modules and Host Interface (Continued)
www.national.com 354 Revision1.07
PC87591E/S/L
Date Of Month Alarm Register Offset (DOMAO)
Location: Index F116
Type: R/W
Month Alarm Register Offset (MONAO)
Location: Index F216
Type: R/W
Century Register Offset (CENO)
Location: Index F316
Type: R/W
6Block RAM Write.
0: No effect on RAM access (default)
1: Writes to RAM (Standard and Extended) are ignored
7Block Standard RAM.
0: No effect on Standard RAM access (default)
1: Reads and writes to locations 3816-3F16 of the Standard RAM are blocked, writes are ignored and reads return
FF16
Bit 76543210
Name Reserved Date of Month Alarm Register Offset Value
Reset 00000000
Bit Description
6-0 Date of Month Alarm Register Offset Value.
7Reserved.
Bit 76543210
Name Reserved Month Alarm Register Offset Value
Reset 00000000
Bit Description
6-0 Month Alarm Register Offset Value.
7Reserved.
Bit 76543210
Name Reserved Century Register Offset Value
Reset 00000000
Bit Description
6-0 Century Register Offset Value.
7Reserved.
Bit Description
6.0 Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 355 www.national.com
PC87591E/S/L
6.1.13 Power Management Interface Channel 1 Configuration
Logical Device 17 (1116) Power Management Channel 1
Table 63 lists the configuration registers that affect Power Management I/F Channel 1
See “Standard Logical Device Configuration Register Definitions” on page 337 and Section 6.1.2 on page 340 for descrip-
tions of the other configuration registers.
Table 63. Power Management Configuration Registers
6.1.14 Power Management Interface Channel 2 Configuration
Logical Device 18 (1216) Power Management Channel 2
Table 64 lists the configuration registers that affect Power Management I/F Channel 2. See Section 6.1.2 on page 340 for
descriptions of the other configuration registers.
Table 64. Power Management Configuration Registers
Index Power Management Channel 1 Configuration Register or Action Type Reset
3016 Activate. See also bit 0 of the SIOCF1. R/W 0016
6016 Data Register Base Address MSB register. Bits 7-3 (for A15-11) are read only,
‘00000’. R/W 0016
6116 Data Register Base Address LSB register. R/W 6216
6216 Command/Status Base Address MSB register. Bits 7-3 (for A15-11) are read
only, ‘00000’. R/W 0016
6316 Command/Status Base Address LSB. R/W 6616
7016 PM Interrupt Number and Wake-Up on IRQ Enable register. R/W 0116
7116 PM Interrupt Type. Bit 1 is read/write; other bits are read only. R/W 0316
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
Index Power Management 2 Configuration Register or Action Type Reset
3016 Activate. See also bit 0 of the SIOCF1. R/W 0016
6016 Data Register Base Address MSB register. Bits 7-3 (for A15-11) are read only,
‘00000‘. R/W 0016
6116 Data Register Base Address LSB register. R/W 6816
6216 Command/Status Base Address MSB register. Bits 7-3 (for A15-11) are read
only, ‘00000’. R/W 0016
6316 Command/Status Base Address LSB. R/W 6C16
7016 PM Interrupt Number and Wake-Up on IRQ Enable register. R/W 0116
7116 PM Interrupt Type. Bit 1 is read/write; other bits are read only. R/W 0316
7416 Report no DMA assignment. RO 0416
7516 Report no DMA assignment. RO 0416
Host-Controlled Modules and Host Interface (Continued)
www.national.com 356 Revision1.07
PC87591E/S/L
6.2 REAL-TIME CLOCK (RTC)
The RTC provides timekeeping and calendar management capabilities. It uses a 32.768 KHz signal as the basic clock for
timekeeping. The RTC also includes 242 bytes of battery-backed RAM for general-purpose use.
The RTC provides the following functions:
Accurate timekeeping and calendar management
Alarm at a predetermined time and/or date
Three programmable interrupt sources
Valid timekeeping during power-down, by utilizing external battery backup
242 bytes of battery-backed RAM
RAM lock schemes to protect its content
Internal oscillator circuit (the crystal itself is off-chip) or external clock supply for the 32.768 KHz clock
A century counter
PnP support:
Relocatable index and data registers
Module access enable/disable option
Host interrupt enable/disable option
Additional low-power features such as:
Automatic switching from battery to VCC
Internal power monitoring on the VRT bit
Oscillator disabling to save battery during storage
Software compatible with the DS1287 and MC146818
6.2.1 Bus Interface
The RTC function is initially mapped to the default SuperI/O locations at indexes 7016 to 7316 (two Index/Data pairs). These
locations may be reassigned in compliance with Plug and Play requirements.
6.2.2 RTC Clock Generation
The RTC uses a 32.768 KHz clock signal as the basic clock for timekeeping. The 32.768 KHz clock is generated by the in-
ternal oscillator circuit or by an external oscillator (see Sections 6.2.3 and 6.2.4).
6.2.3 Internal Oscillator
The internal oscillator employs an external crystal connected to the on-chip amplifier. The on-chip amplifier is accessible on
the 32KX1 input pin and the 32KX2 output pin. See Figure 113 for the recommended external circuit and Table 65 for a list-
ing of the circuit components. The oscillator may be disabled in certain conditions. See Section 6.2.12 on page 362 for more
details.
Figure 113. Recommended Oscillator External Circuitry
VBAT
CF Internal
External
R2
32KX1 / 32KX2
C1 C2
R1
Y
To other
modules
Battery
B1
CF = 0.1 µF
32KCLKIN
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 357 www.national.com
PC87591E/S/L
Table 65. Crystal Oscillator Circuit Components
External Elements
Choose C1 and C2 capacitors (see Figure 113) to match the crystal’s load capacitance. The load capacitance CL“seen” by
crystal Y is comprised of C1in series with C2and in parallel with the parasitic capacitance of the circuit. The parasitic ca-
pacitance is caused by the chip package, board layout and socket (if any), and can vary from 0 to 8 pF. The rule of thumb
for choosing these capacitors is:
CL = (C1 * C2) / (C1 + C2) + CPARASITIC
Oscillator Start-Up
The oscillator starts to generate 32.768 KHz pulses to the RTC after approximately t32KW from when VBAT is higher than
VBATMIN (2.4 V) or from when VCC is higher than VCCMIN (3.0V).
C1can be trimmed to achieve precisely 32.768 KHz. To achieve a high time accuracy, use crystal and capacitors with low
tolerance and temperature coefficients.
6.2.4 External Oscillator
32.768 KHz can be applied from an external clock source, as shown in Figure 114.
Figure 114. External Oscillator Connections
Connections
Connect the clock to the 32KCLKIN pin, leaving the oscillator output, 32KX2, unconnected.
Component Parameters Values Tolerance
Crystal Resonance Frequency 32.768 KHz Parallel Mode User defined
Type N-Cut or XY-bar
Serial Resistance 40 KMax
Quality Factor, Q 35000 Min
Shunt Capacitance 2 pF Max
Load Capacitance, CL9-13 pF
Temperature Coefficient User defined
Resistor R1Resistance 20 M5%
Resistor R2Resistance 121 K5%
Capacitor C1Capacitance 10 pF 10%
Capacitor C2Capacitance 12 pF 10%
32.768 KHz
Clock Generator
Internal
External
32KCLKIN / 32KX2
NC
To other
modules
Battery
VBAT
B1
CF
CF
OUT
POWER
CF = 0.1 µF
32KX1
Host-Controlled Modules and Host Interface (Continued)
www.national.com 358 Revision1.07
PC87591E/S/L
Signal Parameters
The signal levels should conform to the voltage level requirements for 32KCLKIN/32KX1, stated in Section 7 on page 372.
The signal should have a duty cycle of approximately 50%. To oscillate during power-down, it should be sourced from a
battery-backed source. This guarantees that the RTC delivers updated time/calendar information.
6.2.5 Timing Generation
The timing generation function divides the 32.768 KHz clock by 215 to derive a 1 Hz signal, which serves as the input for the
seconds counter. This is performed by a divider chain composed of 15 divide-by-two latches, as shown in Figure 115.
Figure 115. Divider Chain Control
Bits 6-4 (DV2-0) of CRA register control the following functions:
Normal operation of the divider chain (counting)
Divider chain reset to 0
Oscillator activity when only VBAT power is present (backup state).
The divider chain can be activated by setting normal operational mode (bits 6-4 of CRA = 0102). The first update occurs
500 ms after divider chain activation.
Bits 3-0 of CRA register select one the of 15 taps from the divider chain to be used as a periodic interrupt. The periodic flag
becomes active after half of the programed period has elapsed, following divider chain activation.
See “RTC Control Register A (CRA)” on page 367 for more details.
6.2.6 Timekeeping
Data Format
Time is kept in BCD or binary format, as determined by bit 2 (DM) of Control Register B (CRB), and in either 12 or 24-hour
format, as determined by bit 1 of this register.
Note: When changing the above formats, re-initialize all the time registers.
Daylight Saving
Daylight saving time exceptions are handled automatically, as described in the RTC Control Register B (CRB) in
Section 6.2.15 on page 363.
Leap Years
Leap year exceptions are handled automatically by the internal calendar function. Every four years, February is extended to
29 days. Year 2000 is a leap year.
32.768 KHz
2
12
22
32
13 2
14 2
15 1Hz
Divider Chain
DV2 DV1 DV0
CRA Register
Oscillator
Enable
32KX1 / 32KX2
To other
Reset
654
modules
32KCLKIN
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 359 www.national.com
PC87591E/S/L
6.2.7 Updating
The time and calendar registers are updated once per second regardless of bit 7 (SET) of CRB register. Since the time and
calendar registers are updated serially, unpredictable results may occur if they are accessed during the update. Therefore,
it is essential to ensure that reading or writing to the time storage locations does not coincide with a system update of these
locations. There are several methods to avoid this contention.
Method 1
1. Set bit 7 of CRB register to 1. This takes a “snapshot” of the internal time registers and loads them into the user copy
registers. The user copy registers are seen when accessing the RTC from outside and are part of the double buffering
mechanism. This bit may be kept set for up to 1 second, since the time/calendar chain continues to be updated once per
second.
2. Read or write the required registers (since bit 1 is set, the access is to the user copy registers). If a read operation is
performed, the information read is correct from the time bit 1 was set. If a write operation is performed, the write is only
to the user copy registers.
3. Reset bit 1 to 0. During the transition, the user copy registers update the internal registers, using the double buffering
mechanism to ensure that the update is performed between two time updates. This mechanism enables new time pa-
rameters to be loaded in the RTC.
Method 2
1. Access the RTC registers after detection of an Update Ended interrupt. This implies that an update has just been com-
pleted, and 999 ms remain until the next update.
2. To detect an Update Ended interrupt, do one of the following:
Poll bit 4 of CRC register.
Use the following interrupt routine:
a. Set bit 4 of CRB register.
b. Wait for an interrupt from interrupt pin.
c. Clear the IRQF flag of CRC register before exiting the interrupt routine.
Method 3
Poll bit 7 of CRA register. The update occurs 244 µs after this bit goes high. Therefore, if a 0 is read, the time registers remain
stable for at least 244 µs.
Method 4
Use a periodic interrupt routine to determine if an update cycle is in progress, as follows:
1. Set the periodic interrupt to the desired period.
2. Set bit 6 of CRB register to enable the interrupt from periodic interrupt.
3. Wait for the periodic interrupt to occur. This indicates that the period represented by the following expression remains
until another update occurs:
[(Period of periodic interrupt / 2) + 244 µs]
6.2.8 Alarms
The timekeeping function can be set to generate an alarm when the current time reaches a stored alarm time. After each
RTC time update (every 1 second), the seconds, minutes, hours, date of month and month counters are compared with their
corresponding registers in the alarm settings. If equal, bit 5 of CRC register is set. Bit 5 of CRC is sent to the MSWC as an
alarm signal. If the Alarm Interrupt Enable bit was previously set (bit 5 of CRB register), interrupt request pin is also active.
Any alarm register may be set to “Unconditional Match” by setting bits 7-6 to ‘11’. This combination, not used by any BCD
or binary time codes, results in a periodic alarm. The rate of this periodic alarm is determined by the registers that were set
to “Unconditional Match”.
For example, if all but the seconds and minutes alarm registers are set to “Unconditional Match”, an interrupt is generated
every hour at the specified minute and second. If all but the seconds, minutes and hours alarm registers are set to “Uncon-
ditional Match”, an interrupt is generated every day at the specified hour, minute and second.
Host-Controlled Modules and Host Interface (Continued)
www.national.com 360 Revision1.07
PC87591E/S/L
6.2.9 Power Supply
The PC87591x is supplied from four supply voltages, as shown in Figure 116 (see Section 3.1 on page 62 for more detailed
description):
System power supply voltage, VDD
System analog power supply voltage, AVCC
System standby power supply voltage, VCC
Backup voltage, from low-capacity Lithium battery
A standby voltage (VCC) from the external AC/DC power supply powers the RTC under normal conditions.
Figure 116. Power Supply Connections
Figure 117 shows a typical battery configuration. No external diode is required to meet the UL standard, because of the in-
ternal switch and internal serial resistor RUL.
Figure 117. Typical Battery Configuration
RTC power is supplied from either VCC or VBAT voltage source, according to the sources’ levels. An internal voltage com-
parator delivers the control signals to a pair of switches. When VCC is active, the RTC power is drawn from it. Battery backup
voltage (VBAT) maintains the correct time and saves the CMOS memory when the VCC voltage is absent due to power failure
or disconnection of the main battery. Figure 117 illustrates the mechanism whereby VCC or VBAT is selected.
To assure that the module uses power from VCC and not from VBAT, the VCC voltage should be maintained above its
minimum (VCC2PP), as detailed in Section 7 on page 372. Figure 118 illustrates the switching between VCC (thick green
line) and VBAT (thin red line) and vice-versa for generating VPP (thin blue line).
The actual voltage point where the PC87591x switches from VBAT to VCC is lower than the minimum workable battery volt-
age but high enough to guarantee the correct functionality of the oscillator and the CMOS RAM.
The Valid RAM and Timer bit (VRT) in CRD register indicates the state of non-interrupted power supplied to the
PC87591x RTC module. VRT is cleared once VPP power is lost, i.e., when VCC and VBAT are both below VLOWBAT. The
host code should read this bit as part of the startup routine, before using the timer or the CMOS-RAM contents. In case
a value of 0 is read, the RAM and timer must be initialized before use. The VRT bit is set once read.
RTC
Power
Backup
VDD
VCC
VDD
VCC
VBAT Battery
External AC Power
Supply
VDD Sense
VCC
VBAT
VCC
PC0
VBAT
ONCTL ONCTL
ACPI Controller
AVCC
VBAT
0.1 µF
VCC
VCC
CF
CF
BT1
0.1 µF
VPP
RUL
VREF
RTC
1. Place a 0.1 µF capacitor on each VCC power supply
pin as close as possible to the pin, and also on VBAT.
2. Place a 10-47 µF capacitor on the common power
supply net as close as possible to the device.
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 361 www.national.com
PC87591E/S/L
Figure 119 shows typical battery current consumption during battery-backed operation; Figure 120 shows typical battery
current consumption during normal operation.
Figure 119. Typical Battery Current During Battery-Backed Power Mode
Figure 120. Typical Battery Current During Normal Operation Mode
6.2.10 System Bus Lockout
During power on or power off, spurious bus transactions from the host may occur. To protect the RTC internal registers from
corruption, all inputs are automatically locked out. The lockout condition is asserted when VCC is lower than VCCON.
6.2.11 Power-Up Detection
When system power is restored after a power failure or power off state (VCC=0), the lockout condition continues for a delay
of 62 ms (minimum) to 125 ms (maximum) after the RTC switches from battery to system power.
The lockout condition is switched off immediately in the following situations:
If the Divider Chain Control bits, DV0-2, (bits 6-4 in CRA register) specify a normal operation mode (0102), all input
signals are enabled immediately on detection of system voltage above VCCON.
When battery voltage is below VBATDCT and host domain hardware reset is active, all input signals are enabled im-
mediately on detection of system voltage above VCCON. This also initializes registers at offsets 0016 through 0D16.
If bit 7 (VRT) of CRD register is 0, all input signals are enabled immediately on detection of system voltage above VCCON.
time
V
CC
VPP
VBAT
3.3V - 3.6V
VCC2PP
VPP2CC
VPP uses VCC VPP uses VBAT
Figure 118. VPP Generation Using VCC or VBAT
VPP
VBAT
V
CC
VPP uses VBAT
IBAT (µA)
1.0
0.9
0.8
0.7
2.4 3.0 3.6 VBAT (V)
IBAT (µA)
0.20
0.15
0.10
0.05
3.0 3.3 3.6 VCC
Note: Battery voltage in this test is 3.0V.
(V)
Host-Controlled Modules and Host Interface (Continued)
www.national.com 362 Revision1.07
PC87591E/S/L
6.2.12 Oscillator Activity
The RTC oscillator is active if:
VCC power supply is higher than VCCON, independent of the battery voltage, VBAT.
VBAT power supply is higher than VBATMIN whether or not VCC is present.
The RTC oscillator is disabled in the following cases:
During power-down (VBAT only), if the battery voltage drops below VBATMIN, the PC87591x may enter Battery Fail
state. In this case, the oscillator may stop oscillating and memory contents may be corrupted or lost.
Software wrote 00X to DV2-0 bits of CRA register and VCC is removed. This disables the oscillator and decreases
the power consumption from the battery connected to the VBAT pin. When disabling the oscillator, the CMOS RAM is
not affected as long as the battery is present at a correct voltage level.
If the RTC oscillator becomes inactive, the following features are dysfunctional/disabled:
Timekeeping
Periodic interrupt
Alarm
6.2.13 Interrupt Handling
The RTC has a single Interrupt Request line, which handles the following three interrupt conditions:
Periodic interrupt
Alarm interrupt
Update end interrupt
The interrupts are generated if the respective enable bits in CRB register are set prior to an interrupt event occurrence.
Reading the CRC register clears all interrupt flags. Therefore, when multiple interrupts are enabled, the interrupt service
routine should first read and store the CRC register and then deal with all pending interrupts by referring to this stored status.
If an interrupt is not serviced before a second occurrence of the same interrupt condition, the second interrupt event is lost.
Figure 121 illustrates the interrupt timing in the RTC.
Figure 121. Interrupt/Status Timing
Flags (and IRQ) are reset at the conclusion of CRC read
or by reset.
A = Update In Progress bit high before
update occurs = 244 µs
B = Periodic interrupt to update
= Period (periodic int) / 2 + 244 µs
C = Update to Alarm Interrupt = 30.5 µs
P = Period is programed by RS3-0 of CRA
Bit 7
Bit 4
Bit 6
Bit 5
A
C
of CRA
of CRC
of CRC
of CRC
P/2 P/2
244 µs
30.5 µs
B
P
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 363 www.national.com
PC87591E/S/L
6.2.14 Battery-Backed RAMs and Registers
The RTC has two battery-backed RAMs and 17 registers, used by the logical units themselves. Battery-backup power en-
ables information retention during system power down.
The RAMs are:
Standard RAM
Extended RAM
The memory maps and register content of the RAMs are shown in Section 6.2.18 on page 371 and illustrated in Figure 122.
The first 14 bytes and three programmable bytes of the Standard RAM are overlaid by time, alarm data and control registers.
The remaining 111 bytes are general-purpose memory.
Registers with reserved bits should be written using the “Read-Modify-Write” method.
All register locations within the device are accessed by the RTC Index and Data registers (at base address and base ad-
dress+1, as defined by RTC configuration registers at index 6016 and 6116). The Index register points to the register location
being accessed, and the Data register contains the data to be transferred to or from the location. An additional 128 bytes of
battery-backed RAM (also called Extended RAM) may be accessed via a second pair of Index and Data registers (at base
address and base address+1, as defined by RTC configuration registers in index 6216 and 6316).
Access to the two RAMs may be locked. For details, see ”RAM Lock Register (RLR)” in Section 6.1.12 on page 353.
The index of three of the RTC registers is programmable using registers in the RTC logical device bank (part of the SuperI/O
configuration registers). If enabled, these registers override three of the Standard RAM locations; see Section 6.1.12 on
page 353.
6.2.15 RTC Registers
The RTC registers can be accessed at any time during normal operation mode; i.e., when VCC is within the recommended
operation range. This access is disabled during battery-backed operation. Write operation to these registers is also disabled
if bit 7 of CRD register is 0.
Note: Before attempting to perform any start-up procedures, read the explanation of bit 7 (VRT) of CRD register.
See Section 6.2.18 on page 371 for a detailed description of the memory map for the RTC registers.
This section describes the RTC Timing and Control registers, which control basic RTC functionality.
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
0016
0D16
7F16
0E16
Registers
Standard RAM
(3-byte override by
register with
0016
7F16
Index Data
SIO Configuration Extended Bank
(Legacy 0x72, 0x73)
Standard Bank
(Legacy 0x70, 0x71)
Index Data
6016
6316
7F16
7016
7316 prog. indexes
RAM lock
programmable indexes)
}
}
Base Base+1
Index Data
Base Base+1
Figure 122. RTC Module Registers Mapping
Host-Controlled Modules and Host Interface (Continued)
www.national.com 364 Revision1.07
PC87591E/S/L
RTC Register Map
Seconds Register (SEC)
Location: Index 0016
Type: R/W
Index Mnemonic Name Type Reset
0016 SEC Seconds Register R/W VPP PUR
0116 SECA Seconds Alarm Register R/W VPP PUR
0216 MIN Minutes Register R/W VPP PUR
0316 MINA Minutes Alarm Register R/W VPP PUR
0416 HOR Hours Register R/W VPP PUR
0516 HORA Hours Alarm Register R/W VPP PUR
0616 DOW Day Of Week Register R/W VPP PUR
0716 DOM Date Of Month Register R/W VPP PUR
0816 MON Month Register R/W VPP PUR
0916 YER Year Register R/W VPP PUR
0A16 CRA RTC Control Register A R/W Bit specific
0B16 CRB RTC Control Register B R/W Bit specific
0C16 CRC RTC Control Register C R/O Bit specific
0D16 CRD RTC Control Register D R/O VPP PUR
Programmable1
1. Overlaid on RAM bytes in range 0E16-7F16.
DOMA Date of Month Alarm Register R/W VPP PUR
Programmable1MONA Month Alarm Register R/W VPP PUR
Programmable1CEN Century Register R/W VPP PUR
Bit 76543210
Name Seconds Data
Reset 00000000
Bit Description
7-0 Seconds Data. Values may be 00 to 59 in BCD format or 00 to 3B in binary format.
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 365 www.national.com
PC87591E/S/L
Seconds Alarm Register (SECA)
Location: Index 0116
Type: R/W
Minutes Register (MIN)
Location: Index 0216
Type: R/W
Minutes Alarm Register (MINA)
Location: Index 0316
Type: R/W
Hours Register (HOR)
Location: Index 0416
Type: R/W
Bit 76543210
Name Seconds Alarm Data
Reset 00000000
Bit Description
7-0 Seconds Alarm Data. Values may be 00 to 59 in BCD format or 00 to 3B in binary format.
When bits 7 and 6 are both set to one (“11”), unconditional match is selected.
Bit 76543210
Name Minutes Data
Reset 00000000
Bit Description
7-0 Minutes Data. Values may be 00 to 59 in BCD format or 00 to 3B in binary format.
Bit 76543210
Name Minutes Alarm Data
Reset 00000000
Bit Description
7-0 Minutes Alarm Data. Values may be 00 to 59 in BCD format or 00 to 3B in binary format.
When bits 7 and 6 are both set to one (“11”), unconditional match is selected.
Bit 76543210
Name Hours Data
Reset 00000000
Bit Description
7-0 Hours Data. For 12-hour mode, values may be 01 to 12 (a.m.) and 81 to 92 (p.m.) in BCD format or 01 to 0C
(a.m.) and 81 to 8C (p.m.) in binary format. For 24-hour mode, values may be 00 to 23 in BCD format or 00 to
17 in binary format.
Host-Controlled Modules and Host Interface (Continued)
www.national.com 366 Revision1.07
PC87591E/S/L
Hours Alarm Register (HORA)
Location: Index 0516
Type: R/W
Day Of Week Register (DOW)
Location: Index 0616
Type: R/W
Date Of Month Register (DOM)
Location: Index 0716
Type: R/W
Month Register (MON)
Location: Index 0816
Type: R/W
Bit 76543210
Name Hours Alarm Data
Reset 00000000
Bit Description
7-0 Hours Alarm Data. For 12-hour mode, values may be 01 to 12 (a.m.) and 81 to 92 (p.m.) in BCD format or 01
to 0C (a.m.) and 81 to 8C (p.m.) in binary format. For 24-hour mode, values may be 00 to 23 in BCD format or
00 to 17 in binary format.
When bits 7 and 6 are both set to one (“11”), unconditional match is selected.
Bit 76543210
Name Day Of Week Data
Reset 00000000
Bit Description
7-0 Day Of Week Data. Values may be 01 to 07 in BCD format or 01 to 07 in binary format.
Bit 76543210
Name Date Of Month Data
Reset 00000000
Bit Description
7-0 Date Of Month Data. Values may be 01 to 31 in BCD format or 01 to 1F in binary format.
Bit 76543210
Name Month Data
Reset 00000000
Bit Description
7-0 Month Data. Values may be 01 to 12 in BCD format or 01 to 0C in binary format.
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 367 www.national.com
PC87591E/S/L
Year Register (YER)
Location: Index FF16
Type: R/W
RTC Control Register A (CRA)
This register controls test selection, among other functions and cannot be written before reading bit 7 of the CRD register.
Location: Index 0A16
Type: R/W
Table 66. Divider Chain Control and Test Selection
Bit 76543210
Name Year Data
Reset 00000000
Bit Description
7-0 Year Data. Values may be 00 to 99 in BCD format or 00 to 63 in binary format.
Bit 76543210
Name Update in
Progress Divider Chain Control 2-0 Periodic Interrupt Rate Select 3-0
Reset 00100000
Bit Description
3-0 Periodic Interrupt Rate Select. These R/W bits select one of 15 output taps from the clock divider chain to
control the rate of the periodic interrupt (see Table 67 on page 368 and Figure 115 on page 358). They are
cleared to 0002as long as bit 7 of CRD register is 0.
6-4 Divider Chain Control. These R/W bits control the configuration of the divider chain for timing generation and
register bank selection (see Table 66). They are cleared to 0002as long as bit 7 of CRD register is 0.
7Update in Progress. This RO bit is not affected by reset; it is 0 when bit 7 of CRB register is 1.
0: Timing registers not updated within 244 µs
1: Timing registers updated within 244 µs
DV2 DV1 DV0 Configuration
CRA6 CRA5 CRA4
0 0 X Oscillator Disabled
0 1 0 Normal Operation
011Test
10X
1 1 X Divider Chain Reset
Host-Controlled Modules and Host Interface (Continued)
www.national.com 368 Revision1.07
PC87591E/S/L
RTC Control Register B (CRB)
Location: Index 0B16
Type: R/W
.
Table 67. Periodic Interrupt Rate Encoding
Rate Select
3210 Periodic Interrupt
Rate (ms) Divider Chain
Output
0 0 0 0 No interrupts -
0 0 0 1 3.906250 7
0 0 1 0 7.812500 8
0 0 1 1 0.122070 2
0 1 0 0 0.244141 3
0 1 0 1 0.488281 4
0 1 1 0 0.976562 5
0 1 1 1 1.953125 6
1 0 0 0 3.906250 7
1 0 0 1 7.812500 8
1 0 1 0 15.625000 9
1 0 1 1 31.250000 10
1 1 0 0 62.500000 11
1 1 0 1 125.000000 12
1 1 1 0 250.000000 13
1 1 1 1 500.000000 14
Bit 76543210
Name
Set Mode Periodic
Interrupt
Enable
Alarm
Interrupt
Enable
Update
Ended
Interrupt
Enable
Reserved Data Mode Hour Mode Daylight
Savings
Reset 00000000
Bit Description
0Daylight Savings. This bit is reset at VPP Power-Up reset only.
0: Disabled
1: Enabled
In the spring, time advances from 1:59:59 AM to 3:00:00 AM on the first Sunday in April.
In the fall, time returns from 1:59:59 AM to 1:00:00 AM on the last Sunday in October.
1Hour Mode. This bit is reset at VPP Power-Up reset only.
0: 12-hour format enabled
1: 24-hour format enabled
2Data Mode. This bit is reset at VPP Power-Up reset only.
0: BCD format enabled
1: Binary format enabled
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 369 www.national.com
PC87591E/S/L
RTC Control Register C (CRC)
Location: Index 0C16
Type: RO
3Reserved. This bit is defined as “Square Wave Enable” by MC146818 and is not supported by the RTC. It is
always read as 0.
4Update Ended Interrupt Enable. This interrupt is generated when an update occurs. It is cleared to 0 on RTC
reset (i.e., host domain reset) or when the RTC is disabled.
0: Disabled
1: Enabled
5Alarm Interrupt Enable. This interrupt is generated immediately after a time update in which the seconds,
minutes, hours, date and month time equal their respective alarm counterparts. It is cleared to 0 as long as bit
7 of CRD register is 0.
0: Disabled
1: Enabled
6Periodic Interrupt Enable. Bits 3-0 of CRA register determine the rate at which this interrupt is generated. It is
cleared to 0 on RTC reset (i.e., host domain reset) or when RTC is disabled.
0: Disabled
1: Enabled
7Set Mode. This bit is reset at VPP Power-Up reset only.
0: Timing updates occur normally
1: User copy of time is “frozen”, allowing the time registers to be accessed whether or not an update occurs
Bit 76543210
Name
IRQF Periodic
Interrupt
Flag
Alarm
Interrupt
Flag
Update
Ended
Interrupt
Flag
Reserved
Reset 00000000
Bit Description
3-0 Reserved.
4Update Ended Interrupt Flag. This RO bit is cleared to 0 on RTC reset (i.e., host domain reset) or when the
RTC is disabled. In addition, this bit is cleared to 0 when this register is read.
0: No update occurred since the last read
1: Time registers update
5Alarm Interrupt Flag. This RO bit is cleared to 0 as long as bit 7 of CRD register is 0. In addition, this bit is
cleared to 0 when this register is read.
0: No alarm detected since the last read
1: Alarm condition detected
6Periodic Interrupt Flag. This RO bit is cleared to 0 on RTC reset (i.e., host domain reset) or when the RTC is
disabled. In addition, this bit is cleared to 0 when this register is read.
0: No transition occurred on the selected tap since the last read
1: Transition occurred on the selected tap of the divider chain
7IRQF (IRQ Flag). This RO bit mirrors the value of the interrupt output signal. When interrupt is active, IRQF is
1. To clear this bit (and deactivate the interrupt), read CRC register; this clears flags UF, AF and PF, which
results in IRQF being cleared, as well.
0: IRQ inactive
1: Logic equation is true: ((UIE and UF) or (AIE and AF) or (PIE and PF))
Bit Description
Host-Controlled Modules and Host Interface (Continued)
www.national.com 370 Revision1.07
PC87591E/S/L
RTC Control Register D (CRD)
Location: Index 0D16
Type: RO
Date of Month Alarm Register (DOMA)
Location: Programmable Index
Type: R/W
Month Alarm Register (MONA)
Location: Programmable Index
Type: R/W
Bit 76543210
Name Valid RAM
and Time Reserved
Reset 00000000
Bit Description
6-0 Reserved.
7Valid RAM and Time. This bit senses the voltage that feeds the RTC (VCC or VBAT) and indicates whether or
not it was too low since the last time this bit was read. If it was too low (i.e., < VLOWBAT), the RTC contents
(time/calendar registers and CMOS RAM) are not valid. This bit is set after the CRD is read.
0: The voltage that feeds the RTC was too low
1: RTC contents (time/calendar registers and CMOS RAM) valid
Bit 76543210
Name Date of Month Alarm Data
Reset 11000000
Bit Description
7-0 Date of Month Alarm Data. Values may be 01 to 31 in BCD format or 01 to 1F in binary format.
When bits 7 and 6 are both set to one (“11”), unconditional match is selected (default).
Bit 76543210
Name Month Alarm Data
Reset 11000000
Bit Description
7-0 Month Alarm Data. Values may be 01 to 12 in BCD format or 01 to 0C in binary format.
When bits 7 and 6 are both set to one (“11”), unconditional match is selected (default).
Host-Controlled Modules and Host Interface (Continued)
Revision 1.07 371 www.national.com
PC87591E/S/L
Century Register (CEN)
Location: Programmable Index
Type: R/W
6.2.16 BCD and Binary Formats
6.2.17 Usage Hints
1. Read bit 7 of CRD register at each system power-up to validate the contents of the RTC registers and the CMOS RAM.
When this bit is 0, the contents of these registers and the CMOS RAM are questionable. This bit is reset when the backup
battery voltage is too low. The voltage level at which this bit is reset is below the minimum recommended battery voltage,
2.4V. Although the RTC oscillator may function properly and the register contents may be correct at lower than 2.4V, this
bit is reset since correct functionality cannot be guaranteed. System BIOS may use a checksum method to revalidate
the contents of the CMOS-RAM. The checksum byte should be stored in the same CMOS RAM.
2. Change the backup battery while normal operating power is present, and not in backup mode, to maintain valid time and
register information. If a low leakage capacitor is connected to VBAT, the battery may be changed in backup mode.
3. A rechargeable NiCd battery may be used instead of a non-rechargeable Lithium battery. This is the preferred solution
for portable systems, where small components are essential.
4. A supercap capacitor may be used instead of the normal Lithium battery. In a portable system, typically, the VSB voltage
is always present because the power management stops the system before its voltage falls to low. A supercap capacitor
in the range of 0.047F-0.47F should be able to supply the power during a battery replacement.
6.2.18 RTC General-Purpose RAM Map
Table 68. Standard RAM Map
Table 69. Extended RAM Map
Bit 76543210
Name Century Data
Reset 00000000
Bit Description
7-0 Century Data. Values may be 00 to 99 in BCD format or 00 to 63 in binary format.
Parameter BCD Format Binary Format
Seconds 00 to 59 00 to 3B
Minutes 00 to 59 00 to 3B
Hours 12-hour mode:01 to 12 (a.m.); 81 to 92 (p.m.)
24-hour mode:00 to 23 12-hour mode:01 to 0C (a.m.); 81 to 8C (p.m.)
24-hour mode:00 to 17
Day 01 to 07 (Sunday = 01) 01 to 07
Date 01 to 31 01 to 1F
Month 01 to 12 (January = 01) 01 to 0C
Year 00 to 99 00 to 63
Century 00 to 99 00 to 63
Index Description
0E16 -7F
161
1. Battery-backed 111-byte RAM (114 3 overlaid registers).
Battery-backed general-purpose 111-byte RAM.
Index Description
0016 -7F
16 Battery-backed general-purpose 128-byte RAM.
www.national.com 372 Revision1.07
PC87591E/S/L
7.0 Device Specifications
This section provides the power and grounding guidelines for the PC87591x, specifies the device’s maximum ratings and
electrical characteristics and describes its timing.
7.1 GENERAL DC ELECTRICAL CHARACTERISTICS
7.1.1 Recommended Operating Conditions
7.1.2 Absolute Maximum Ratings
If military- or aerospace-specified devices are required, please contact a National Semiconductor sales office or distributor
for availability and specifications.
Storage Temperature: 65°C to +150°C
Temperature Under Bias: 0°C to +70°C
Absolute maximum ratings are values beyond which damage to the device may occur. Unless otherwise specified, all volt-
ages are relative to ground.
Symbol Parameter Min Typ Max Unit
VDD Host Domain Supply Voltage 3.0 3.3 3.6 V
VCC Core Domain Supply Voltage 3.0 3.3 3.6 V
AVCC Analog Supply Voltage 3.15 3.3 3.45 V
VBAT Battery Backup Supply Voltage 2.4 3.6 V
TAOperating Temperature 0 +70 °C
Symbol Parameter Conditions Min Max Unit
VDD Host Domain Supply Voltage 0.5 +4.2 V
VCC Core Domain Supply Voltage 0.5 +4.2 V
AVCC Analog Supply Voltage 0.5 +4.2 V
VBAT Battery Backup Supply Voltage 0.5 +4.2 V
VIInput Voltage All other buffer types 0.5 5.5 V
Buffer types: INAC1,IN
AD,IN
DI,IN
OSC,
INPCI,IN
TS (IOPE0-3, IOPE6-7)
1. When ACM is enabled.
0.5 VSUP2+ 0.5
2. VSUP is VDD, VCC, AVCC or VBAT, according to the power well of the input.
V
VOOutput Voltage All other buffer types 0.5 5.5 V
Buffer types: ODA,O
DI,O
OSC,O
PCI 0.5 VSUP3+ 0.5
3. VSUP is VDD, VCC, AVCC or VBAT, according to the power well of the output.
V
TSTG Storage Temperature 65 +165 °C
PDPower Dissipation 1W
TLLead Temperature Soldering (10 s) +260 °C
ESD Tolerance CZAP = 100 pF
RZAP = 1.5 K4
4. Value based on test complying with RAI-5-048-RA human body model ESD testing.
2000 V
7.0 Device Specifications (Continued)
Revision 1.07 373 www.national.com
PC87591E/S/L
7.1.3 Capacitance
7.1.4 Power Supply Current Consumption under Recommended Operating Conditions
7.1.5 Voltage Thresholds
Symbol Parameter Min2Typ1
1. TA = 25°C; f = 1 MHz.
Max2
2. Not tested; guaranteed by characterization.
Unit
CIN Input Pin Capacitance 5 7 pF
CIN1 Clock Input Capacitance 5 8 12 pF
CIO I/O Pin Capacitance 10 12 pF
COOutput Pin Capacitance 6 8 pF
Symbol Parameter Conditions1
1. All parameters specified for 0°C TA 70°C; VDD and VCC = 3.3V ±10% unless otherwise specified.
Typ Max Unit
IDD VDD Average Main Supply Current VIL = 0.5V, VIH = 2.4V
No Load 23mA
IDDLP VDD Quiescent Main Supply Current in Low
Power Mode VIL = GND, VIH =V
DD
No Load 30 50 µA
ICC VCC Active Supply Current tCLK = 250 ns 15 mA
tCLK =50ns 23 30 mA
ICCW VCC Active Executing WAIT Supply Current tCLK = 250 ns 6.6 mA
tCLK =50ns 10 mA
ICCI VCC Idle Mode Supply Current Idle Mode
VIL = GND, VIH =V
CC
No Load
15 µA
IBAT VBAT Battery Supply Current Power Off Mode 0.9 1.5 µA
Symbol Parameter Conditions1
1. All parameters specified for 0°C TA 70°C.
Min Typ Max Unit
VCCON VCC Detected as Power-On 2.5 2.95 V
VCC2PP VCC detected for use as source for VPP 2.3 2.4 V
VPP2CC VCC detected inactive for use of VBAT as
source for VPP
1.9 2.2 V
VDDON VDD Detected as on 2.5 2.95 V
VBATDTC Battery Detected 1.0 1.2 V
VLOWBAT Low Battery Voltage 1.3 1.9 V
VBATMIN Workable Battery Voltage 2.4 V
VBATMAX Battery Input Voltage 3.6 V
7.0 Device Specifications (Continued)
www.national.com 374 Revision1.07
PC87591E/S/L
7.2 DC CHARACTERISTICS OF PINS BY I/O BUFFER TYPES
The following tables summarize the DC characteristics of all device pins described in Chapter 2 on page 39. The character-
istics describe the general I/O buffer types defined in Table 4 on page 41. For exceptions, see Section 7.2.9 on page 376.
For the DC characteristics of the analog pins, see Section 7.4 on page 378. The DC characteristics of the system interface
meet the PCI 2.1 3.3V DC signaling.
7.2.1 Input, CMOS Compatible with Schmitt Trigger
Symbol: INCS
7.2.2 Input, PCI 3.3V
Symbol: INPCI
7.2.3 Input, SMBus Compatible
Symbol: INSM
Symbol Parameter Conditions Min Max Unit
VIH Input High Voltage 0.75 VSUP1
1. VSUP is VDD or VCC, according to the power well of the input.
5.52
2. Not tested; guaranteed by design.
V
VIL Input Low Voltage 0.521.1 V
VHInput Hysteresis 5003
3. Not tested; guaranteed by characterization.
mV
IIL Input Leakage Current 0 < VIN <V
SUP ±14
4. Maximum 10 µA for all pins together.
µA
Symbol Parameter Conditions Min Max Unit
VIH Input High Voltage 0.5 VDD VDD + 0.51
1. Not tested; guaranteed by design.
V
VIL Input Low Voltage 0.510.3 VDD V
lIL2
2. Input leakage current includes the output leakage of the bidirectional buffers with TRI-STATE outputs.
Input Leakage Current 0 < VIN <V
DD ±13
3. Maximum 10 µA for all pins together.
µA
Symbol Parameter Conditions Min Max Unit
VIH Input High Voltage 1.4 5.51
1. Not tested; guaranteed by design.
V
VIL Input Low Voltage 0.5 10.8 V
IIL2
2. Input leakage current includes the output leakage of the bidirectional buffers with TRI-STATE outputs.
Input Leakage Current 0 < VIN <V
DD ±13
3. Maximum 10 µA for all pins together.
µA
7.0 Device Specifications (Continued)
Revision 1.07 375 www.national.com
PC87591E/S/L
7.2.4 Input, TTL Compatible
Symbol: INT
7.2.5 Input, TTL Compatible with Schmitt Trigger
Symbol: INTS
7.2.6 Output, TTL Compatible Push-Pull Buffer
Symbol: Op/n
Output, TTL-compatible, rail-to-rail push-pull buffer that is capable of sourcing pmA and sinking n mA
Symbol Parameter Conditions Min Max Unit
VIH Input High Voltage 2.0 5.51
1. Not tested; guaranteed by design.
V
VIL Input Low Voltage 0.510.8 V
IIL2
2. Input leakage current includes the output leakage of the bidirectional buffers with TRI-STATE outputs.
Input Leakage Current 0 < VIN <V
CC ±13
3. Maximum 10 µA for all pins together.
µA
Symbol Parameter Conditions Min Max Unit
VIH Input High Voltage, 5V tolerant pins1
1. See Section 7.1.2 on page 372.
2.0 5.52
2. Not tested; guaranteed by design.
V
Input High Voltage, pins without 5V tolerance12.0 VSUP3+0.52
3. VSUP is VDD or VCC, according to the power well of the input.
V
VIL Input Low Voltage 0.520.8 V
VHInput Hysteresis 2504
4. Not tested; guaranteed by characterization.
mV
IIL Input Leakage Current 0 < VIN <V
SUP ±15
5. Maximum 10 µA for all pins together.
µA
Symbol Parameter Conditions Min Max Unit
VOH Output High Voltage IOH =pmA 2.4 V
IOH =50 µAVSUP1
0.2
1. VSUP is VDD or VCC, according to the power well of the input.
V
VOL Output Low Voltage IOL =nmA 0.4 V
IOL =50µA 0.2 V
7.0 Device Specifications (Continued)
www.national.com 376 Revision1.07
PC87591E/S/L
7.2.7 Output, Open-Drain Buffer
Symbol: ODn
Output, TTL-compatible open-drain output buffer, capable of sinking nmA. Output from these signals is open-drain and
is never forced high.
7.2.8 Output, PCI 3.3V
Symbol: OPCI I
7.2.9 Exceptions
1. All pins are back-drive protected, except for output pins with PCI buffer type (INPCI or OPCI), oscillator (OOSC) and all
analog type pins (ODA and ODI).
2. The following pins have an internal static pull-up resistor and therefore may have leakage current to VCC (when VIN = 0):
SCL1-2, SDA1-2, IOPA7-0, IOPB7-0, IOPC7-0, IOPD7-0, IOPE7-4, IOPF7-0, KBSIN0-7, PSCLK1-4, PSDAT1-4.
3. Thefollowingstrappinshaveaninternalstaticpull-downresistorenabledduringPower-Upresetandthereforemayhave
leakage current to VSS (when VIN = VSUP): BADDR1-0, ENV1-0, SHBM, TRIS.
4. IOH is valid for a GPIO pin only when it is not configured as open-drain.
7.2.10 Terminology
Back-Drive Protection. Apin that is back-drive protected does not sink currentinto the supply when an input voltage higher
than the supply, but below the pin’s maximum input voltage, is applied to the pin. This is true even when the supply is inac-
tive. Note that active pull-up resistors and active output buffers are typically not back-drive protected.
5-Volt Tolerance. An input signal that is 5V tolerant can operate with input voltage of up to 5V even though the supply to
the device is only 3.3V. The actual maximum input voltage allowed to be supplied to the pin is indicated by the maximum
high voltage allowed for the input buffer. Note that some pins have multiple buffers, not all of which are 5V tolerant. In such
cases, there is a note that indicates at what conditions a 5V input may be applied to the pin; if there is no note, the low max-
imum voltage among the buffers is the maximum voltage allowed for the pin.
Symbol Parameter Conditions Min Max Unit
VOL Output Low Voltage IOL =nmA 0.4 V
IOL =50µA 0.2 V
Symbol Parameter Conditions Min Max Unit
VOH Output High Voltage lout =500 µA 0.9 VDD V
VOL Output Low Voltage lout = 1500 µA 0.1 VDD V
7.0 Device Specifications (Continued)
Revision 1.07 377 www.national.com
PC87591E/S/L
7.3 INTERNAL RESISTORS
DC Test Conditions
Notes:
1. The equivalent resistance of the pull-up resistor is calculated by RPU = (VSUP VPIN) / IPU.
2. The equivalent resistance of the pull-down resistor is calculated by RPD = VPIN / IPD.
7.3.1 Pull-Up Resistor
Symbol: PUnn
7.3.2 Pull-Down Resistor
Symbol: PDnn
Symbol Parameter Conditions Typical Min Max Unit
RPU1
1. Not tested; guaranteed by characterization.
Pull-up equivalent resistance VPIN =0V nn nn 34% nn + 47% K
VPIN = 0.17 VDD nn 44% K
VPIN = 0.8 VDD nn 41% K
Symbol Parameter Conditions Typical Min Max Unit
RPD1
1. Not tested; guaranteed by characterization.
Pull-down equivalent resistance VPIN =V
DD nn nn 35% nn + 60% K
VPIN = 0.17 VDD nn 37% K
VPIN = 0.8 VDD nn 48% K
Device
Under
Test RPU
Pull-Up Resistor Test Circuit Pull-Down Resistor Test Circuit
VSUP
Pin A
IPU
V
VPIN
Device
Under
Test
RPD
VSUP
Pin A
IPD
V
VPIN
VSUP
Figure 123. Internal Resistor Test Conditions, TA=0°Cto70°C, VSUP = 3.3V
7.0 Device Specifications (Continued)
www.national.com 378 Revision1.07
PC87591E/S/L
7.4 ANALOG CHARACTERISTICS
7.4.1 ADC Characteristics
Voltage Measurement
Parameter Symbol Conditions1Min Typ Max Unit
Resolution RES 10 Bit
Offset Error2OERL3AD0-9:
12 mV VIN 0.9 V ±0.25 LSB
OERHAD0-9:
40 mV VIN AVCC 0.8 ±0.25 LSB
OERBAD13:
0.9V VIN AVCC 0.2 ±0.25 LSB
OERVAD10-12:
0.1V VIN VFS ±0.25 LSB
Gain Error4GERLAD0-9:
12 mV VIN 0.9 V ±0.75 LSB
GERHAD0-9:
40 mV VIN AVCC 0.8 ±0.75 LSB
GERBAD13:
0.9V VIN AVCC 0.2 ±0.75 LSB
GERVAD10-12:
0.1V VIN VFS ±0.75 LSB
Integral Non-linearity Error5INLLAD0-9:
12 mV VIN 0.9 V ±0.5 LSB
INLHAD0-9:
40 mV VIN AVCC 0.8 ±0.5 LSB
INLBAD13:
0.9V VIN AVCC 0.2 ±0.5 LSB
INLVAD10-12:
0.1V VIN VFS ±0.5 LSB
Differential Non-linearity Error6DNLLAD0-9:
12 mV VIN 0.9 V ±0.257LSB
DNLHAD0-9:
40 mV VIN AVCC 0.8 ±0.257LSB
DNLBAD13:
0.9V VIN AVCC 0.2 ±0.257LSB
DNLVAD10-12:
0.1V VIN VFS ±0.257LSB
External Inputs Accuracy8EACULAD0-9:
12 mV VIN 0.9 V ±1 LSB
EACUHAD0-9:
40 mV VIN AVCC 0.8 ±1 LSB
7.0 Device Specifications (Continued)
Revision 1.07 379 www.national.com
PC87591E/S/L
Internal Inputs Accuracy8, 9 IACUBAD13:
0.9V VIN AVCC 0.2 ±2 LSB
IACUVAD10-12:
0.1V VIN VFS ±2 LSB
Full Scale Voltage VFSL AD0-9 Low Scale 1.000 V
VFSH AD0-9 High Scale 3.000 V
VFSB AD13 4.000 V
VFSV AD10-12 4.000 V
Input Voltage Range VIN Note10 0AV
CC V
Analog Input Leakage Current IAL AD0-9: 0 VIN AVCC ±1µA
Analog Input Resistance RAIN AD0-9, AD13 4 ΜΩ
Analog Input Capacitance CAIN TBD pF
ADC Clock Frequency FCLK 0.5 MHz
ADC Enable Delay11 tEND 100 µs
Voltage Conversion Duration tVC 8.2 ms
1. All parameters specified for 0°C TA 70°C and AVCC= 3.3V ±5% unless otherwise specified.
2. The difference between 0V and the actual voltage value for code 00016.
3. XXXL = Inputs AD0-9, Low Scale; XXXH = Inputs AD0-9, High Scale; XXXV = Inputs AD10-12;
XXXB = Input AD13.
4. The difference between 1023/1024 * VFS and the actual voltage for code 3FF16.
5. The maximum difference between the ideal (straight) conversion line and the actual conversion curve, not
including the offset, gain and quantization (±0.5 LSB) errors.
6. The maximum difference between an ideal step size (1 LSB) and any actual step size.
7. No missing codes.
8. Total unadjusted error (includes the offset, gain, integral non-linearity and quantization (±0.5 LSB) errors).
9. The internal power supply inputs: VDD, VCC, AVCC.
10. Input Voltage allowed in normal operation. Linear range is as defined for the different measurement modes.
11. Time from the moment when ADCEN=1 in ADCCNF register until the beginning of the “ADC cycle”.
Parameter Symbol Conditions1Min Typ Max Unit
7.0 Device Specifications (Continued)
www.national.com 380 Revision1.07
PC87591E/S/L
Temperature Measurement
7.4.2 ACM Characteristics
Parameter Symbol Conditions1
1. All parameters specified for 0°C TA 70°C and AVCC= 3.3V ±5% unless otherwise specified.
Min Typ Max Unit
Resolution RESB 8 Bit
RESC 1 oC
Accuracy Using Remote Diode2
2. See “Remote Diode Selection” on page 187.
RAC1 TA= +40°C to +100°C±3oC
RAC2 TA=40°C to +125°C±5oC
Accuracy Using Local Diode LAC1 TA= +40°C to +100°C±1oC
LAC2 TA=40°C to +125°C±3oC
Voltage at DN VDN 8µAID120 µA 0.7 V
DP Source Current IDPH High Level 80 120 µA
IDPL Low Level 8 12 µA
Temperature Input Capacitance CTIN TBD pF
ADC Clock Frequency FCLK 0.5 MHz
ADC Enable Delay3
3. Time from the moment when ADCEN=1 in ADCCNF register until the beginning of the “ADC cycle”.
tEND 100 µs
Temperature Conversion Duration tTC 42 ms
Parameter Symbol Conditions1
1. All parameters specified for 0°C TA 70°C and VCC= 3.3V ±10% unless otherwise specified.
Min Typ Max Unit
Resolution RES 6 Bit
Differential Non-linearity Error2
2. The maximum difference between an ideal step size (1 LSB) and any actual step size.
DNL 0 VIN VCC ±0.53
3. No missing codes.
LSB
Accuracy (Total unadjusted error) ACU 0 VIN VCC ±1.5 LSB
Input Voltage Range VIN 0V
CC V
Analog Input Leakage Current IAL 0VIN VCC ±1µA
Analog Input Capacitance CAIN TBD pF
7.0 Device Specifications (Continued)
Revision 1.07 381 www.national.com
PC87591E/S/L
7.4.3 DAC Characteristics
7.5 PACKAGE THERMAL INFORMATION
Thermal resistance (degrees C/W) ThetaJC and ThetaJA values for the various packages of the PC87591x are as follows:
Table 70. Theta (Θ) J Values
Airflow for ThetaJA values is measured in linear feet per minute (lfpm).
Parameter Symbol Conditions1
1. All parameters specified for 0°C TA 70°C. AVCC = 3.3V ± 5%, unless otherwise specified.
Min Typ Max Unit
Resolution RES 8 Bit
Offset Error2
2. The difference between 0V and the actual voltage value for code 0016.
OER AVCC = 3.3V ±1 LSB
Gain Error3
3. The difference between 255/256 * AVCC and the actual voltage for code FF16.
GER AVCC = 3.3V ±1 LSB
Integral Non-linearity Error4
4. The maximum difference between the ideal (straight) conversion line and the actual conversion curve, not
including the offset, gain and quantization (±0.5 LSB) errors.
INL AVCC = 3.3V,
0VOUT AVCC
±0.5 LSB
Differential Non-linearity Error5
5. The maximum difference between an ideal step size (1 LSB) and any actual step size.
DNL AVCC = 3.3V,
0VOUT AVCC
±0.56
6. Monotonic.
LSB
Output Voltage Range VOUT 0AV
CC V
Analog Output Resistance RS0VOUT AVCC 234K
Analog Output Capacitance CAO 10 15 pF
DAC Settling Time7
7. Time from the converter loading with data, to output voltage settling within an error of ±0.5 LSB.
TSET CL=50pF 1 µs
DAC Enable Delay8
8. Time from the moment when DACENn=1 in DACCTRL register until the settling of the output voltage.
TEND CL=50pF 10 µs
Package Type ThetaJA@0 lfpm ThetaJA@225 lfpm ThetaJA@500 lfpm ThetaJA@900 lfpm ThetaJC
128 LQFP 47.1 34.6 29.3 28.8 15.3
176 LQFP 39.8 32.3 29.5 26.2 5.1
7.0 Device Specifications (Continued)
www.national.com 382 Revision1.07
PC87591E/S/L
7.6 AC ELECTRICAL CHARACTERISTICS
7.6.1 AC Test Conditions
Figure 124. AC Test Conditions, TA=0°Cto70°C, VSUP = 3.3V ±10%
Notes:
1. VSUP is VDD, VCC, AVCC or VBAT, according to the power well of the pin.
2. CL = 50 pF for all output pins (this value includes both jig and oscilloscope capacitance).
3. S1 = Open for push-pull output pins.
S1 = VSUP for high impedance to active low and active low to high impedance measurements.
S1 = VSS for high impedance to active high and active high to high impedance measurements.
RL = 1.0 K
The following abbreviations are used in Section 7.6:
RE = Rising Edge
FE = Falling Edge
Definitions
The timing specifications in this section refer to low- or high-level voltage, according to the specific buffer type (TTL or
CMOS) on the rising or falling edges of all the signals, as illustrated in the following figures, unless specifically stated other-
wise.
Figure 125. CMOS Output Signals Specification Conventions
Device
Under
Test
0.1 µf
Input Output
RL
CL
S1
Load Circuit (Notes 1, 2, 3) AC Testing Input, Output Waveform
VSUP
2.4
0.4
2.0
0.8 Test Points 2.0
0.8
CLK
SIG1
SIG2
VOH, VOHhd
VOL, VOLhd
VOH, VOHhd
VOL, VOLhd
tSIG1v tSIG1a Vcc * 0.3
Vcc * 0.7
2.0V 2.40V
Vcc * 0.7
Vcc * 0.3
tSIG2h
tSIG1h
tSIG2v tSIG2a
or tSIG1ia
or tSIG2ia
7.0 Device Specifications (Continued)
Revision 1.07 383 www.national.com
PC87591E/S/L
Figure 126. TTL: Input Signal Specification Standard
Figure 127. CMOS with Hysteresis Inputs
Figure 128. Signal-to-Signal Delay
CLK
SIG1
SIG2
2.4V
0.4V
0.8V
2.0V
0.8V
2.0V
tSIG1s
setup tSIG1h
hold
tSIG2h
hold
tSIG2s
setup
VCHl VCHh
Vhys
2.4V
0.4V
0.8V
2.0V
2.4V
0.4V
0.8V
2.0V
tv
th
SIG1
SIG2
7.0 Device Specifications (Continued)
www.national.com 384 Revision1.07
PC87591E/S/L
7.6.2 Reset Timing
Figure 129. Internal Power-Up Reset
Notes:
1. Either WATCHDOG, Debugger I/F or Power-Up reset.
2. Valid on Power-Up reset only.
Figure 130. Warm Hardware Reset
Symbol Figure Description Reference Conditions Min Max Unit
tSUPUP 130 Supply wake-up time to
95% VCC After VCC >V
CCON 1ms
tIRST 130 Internal or power-on reset
time Power stable to end of 16th clock
cycle of CLK 16 *tCLK +
t32KD
16 *tCLK +
t32KD +t
32KW
-
tIPLv 130 Valid time: Internal strap
pull-up resistors Before end of 16th clock cycle of
CLK 16 *tCLK -
tEPLv 130 Valid time: External strap
pull-up resistors Before end of 16th clock cycle of
CLK 6*tCLK -
tWRST 130 RESET1-2 width RESET1-2 FE to RESET1-2 RE 3 *tCLK -
VCC (Power) 1
CLK
Internal Reset
tIRST
Internal Straps2
tIPLv
Internal
tSUPUP
0.95 VCC
VCCONmin
Reset Event 1
tEPLv
(Pull-down)
External Straps
(Pull-up)
Strap Sampling
Time
CLK
RESET1-2
tWRST
7.0 Device Specifications (Continued)
Revision 1.07 385 www.national.com
PC87591E/S/L
7.6.3 Clock Timing
Symbol Figure Description Reference Conditions Min Max Unit
Clock Input Timing
t32KCLKIN 131 Required clock period for
32KCLKIN From RE to RE of 32KCLKIN
t32NOM = 30.517578 30.5145
(t32NOM
100ppm)
30.5206
(t32NOM +
100ppm)
µs
Clock Output Timing
tCLK 132 CLK period At 2.0V (both edges) 50 250 ns
tCLKh 132 CLK high time At 2.0V (both edges) 0.5 *tCLK
5ns -
tCLKl 132 CLK low time At 0.8V (both edges) 0.5 *tCLK
5ns -
tCLKr 132 CLK rise time 0.8V to 2.0V 6 ns
tCLKf 132 CLK fall time 2.0V to 0.8V 6 ns
tCLKw 133 CLK wake-up time From wake-up event until
CLK starts toggling 100 µs
tCLKINTst 133 tCLK period Active mode in steady state 0.99 *
tCLKINTnom1
1. tCLKINTnom is defined in Table 36 on page 241.
1.01 *
tCLKINTnom
-
tCLKINTwk 133 tCLK period After wake-up from Idle 0.9 *
tCLKINTnom
1.1 *
tCLKINTnom
-
tCLKstab 133 tCLK stabilization time After wake-up from Idle 0.5 s
t32KW 131 32K oscillator wake-up time After VBAT >V
LOWBAT 1s
t32KD 132 CLK delay time After VCC >V
CCON 40 ms
Flash Operation Frequency
fFMAX Flash Section 0 and 1
maximal operation frequency
in Fast Read
CLK period 20 MHz
tFLPMAX Flash Section 0 and 1
maximal operation frequency
in Low Power
CLK period TBD MHz
7.0 Device Specifications (Continued)
www.national.com 386 Revision1.07
PC87591E/S/L
General
Figure 131. 32K Waveforms
32KX2
VBAT t32KW
0V
VCC t32KD
CLK
32KX1/32KCLKIN
0V
t32KCLKIN
7.0 Device Specifications (Continued)
Revision 1.07 387 www.national.com
PC87591E/S/L
Figure 132. Clock Waveforms
Figure 133. Internal Clock Generator
tCLK
CLK
tCLKl
tCLKf tCLKr
Output Valid Output Hold
Output
Signal
Input
Signal
Input Setup Input Hold
Control
Signal 1
Control
Signal 2
tCLKh
Output Active Time
Output Active Time
Wake-Up Event
tCLKINTwk tCLKINTst
tCLKstab
CLK
tCLKw
PC87591x in
Active Mode
PC87591x in
Idle Mode
7.0 Device Specifications (Continued)
www.national.com 388 Revision1.07
PC87591E/S/L
7.6.4 BIU Timing
Symbol Figure Description Reference Conditions Min Max Unit
BIU Input Timing
t1134, 136 to
138 Input setup time
D0-15 Before RE CLK 15 ns
t2134, 136 to
138 Input hold time
D0-15 After RE CLK 0 ns
BIU Output Timing
t3134 to 139 Output valid time
A0-17, BE0,1CBRD, D0-15 After RE CLK 14 ns
t4134 to 139 Output valid time
BST0-2 After RE CLK 0.5 *tCLK
+14ns -
t5134 to 138 Output active/inactive time
RD, SEL0-1, SELIO After RE CLK 14 ns
t6134, 135 Output active/inactive time
WR0-1 After RE CLK 0.5 *tCLK
+14ns -
t7136 Minimum inactive time
RD After RE RD tCLK 5ns -
t8134, 135 Output float time
A0-17, D0-15,RD, SEL0-
1,SELIO,WR0-1
After RE CLK 14 ns
t9134, 135 Minimum delay time From RE RD to
D0-15 drive tCLK 8ns -
t10 135 Minimum delay time From RE RD to RE SELn 0 ns
t11 135 Minimum delay time From RE SELx to FE SELy0 ns
t12 134 to 139 Output hold time
A0-17, BE0-1, CBRD, D0-
15, RD, SEL0-1, SELIO
After RE CLK 0 ns
t13 134 to 139 Output hold time
BST0-2,WR0-1 After RE CLK 0.5 *tCLK
4ns -
t14 135 D0-15 valid in late write
bus cycles Before RE WR0-1 (K + 0.5) *
tCLK 8ns -
7.0 Device Specifications (Continued)
Revision 1.07 389 www.national.com
PC87591E/S/L
Figure 134. Early Write Between Normal Read Bus Cycles
CLK
A0-18
SELx
SELy
RD
WR0,1
D0-15
Normal Early Write Normal
T1 T2 T1 T2 T1 T2
Read Read
T3
In Out In
BST0-2
t1t2
t3
t9
t3
(y x)
t3, t12
t5, t12 t5, t12
t5, t12
t5, t12
t5, t12 t5,
t12
t8,
t12
t6, t13 t6, t13
t4, t13 t4, t13
Idle
Cycle
7.0 Device Specifications (Continued)
www.national.com 390 Revision1.07
PC87591E/S/L
Figure 135. Late Write between Two Normal Read Bus Cycles, 0 Wait, AC Timing
Figure 136. Two Consecutive Normal Read Bus Cycles with Burst, 0 Wait, AC Timing
CLK
A0-18
SELx
D0-15
RD
WR0-1
Normal Read Late Write
T1 T2 T1 T2 T1 T2
Bus State
In Out In
BST0-2
(x y)
SELy
(y x)
t10 t9
t3
t11
Normal Read
t3, t12 t3, t12
t5, t12 t5, t12
t5, t12
t5, t12
t8, t12
t5, t12 t5, t12
t6, t13
t6, t13
t4, t13 t4, t13
t14
CLK
A0-18
SELx
SELy
RD
WR0-1
D0-15
Normal Read Normal Read
T1 T2 T2B T1 T2B
T2
In In In In
BST0-2
t1
t2t2
t1
t7
(x y)
(y x)
t3t3, t12 t3, t12
t5, t12 t5, t12
t5, t12 t5, t12
t5, t12 t5, t12
t4, t13 t4, t13
7.0 Device Specifications (Continued)
Revision 1.07 391 www.national.com
PC87591E/S/L
Figure 137. Normal Read Bus Cycle (2 Internal Waits, and 1 Hold), AC Timing
Figure 138. Fast Read Bus Cycle, AC Timing
CLK
A0-18
SELn,
D0-15
RD
WR0-1
Bus State T1 TIW TIW T2 Thold
BST0-2
t3
t1t2
t4, t13
SELIO
t3, t12
t5, t12 t5, t12
t5, t12 t5, t12
t4, t13
CLK
A0-18
SELx
SELy
RD
WR0-1
D0-15
Fast Late Write Fast
TIdle T1-2 T1 T2 T1-2 T1
Read Read
TIdle
In Out In
BST0-2
(x y)
(y x)
t3
t2
t1
t4, t13 t4, t13
t3, t12
t5, t12 t5, t12
t5, t12 t5, t12
Idle
Cycle
7.0 Device Specifications (Continued)
www.national.com 392 Revision1.07
PC87591E/S/L
Figure 139. Core Bus Monitoring Bus Cycle, AC Timing
CLK
A0-12,
T1
SEL0-1,
WR0-1
D0-15
DBE
RD
BST0-2
SELIO
A16-18
CBRD
BE0-1
t3
t3
t3
t4, t13
t3, t12
t3, t12
t3, t12
7.0 Device Specifications (Continued)
Revision 1.07 393 www.national.com
PC87591E/S/L
7.6.5 GPIO Ports Timing
Symbol Figure Description Reference Conditions Min Max Unit
GPIO Input Timing
tINPs 140 Input setup time IOPA0-7,
IOPB0-7, IOPC0-7, IOPD0-
7, IOPE0-7, IOPF0-7,
IOPG0-7, IOPH0-7, IOPI0-7,
IOPJ0-7, IOPK0-7, IOPL0-4,
IOPM0-7, KBSIN0-71
1. When using the Schmitt input.
Before RE CLK 0.5 *tCLK -
tINPh 140 Input hold time IOPA0-7,
IOPB0-7, IOPC0-7, IOPD0-
7, IOPE0-7, IOPF0-7,
IOPG0-7, IOPH0-7, IOPI0-7,
IOPJ0-7, IOPK0-7, IOPL0-4,
IOPM0-7, KBSIN0-71
After RE CLK 0 ns
GPIO Output Timing
tOUTv 141 Output valid time
KBSOUT0-15, IOPA0-7,
IOPB0-7, IOPC0-7, IOPD0-
7, IOPF0-7, IOPG0-7,
IOPH0-7, IOPI0-7, IOPJ0-7,
IOPK0-7, IOPL0-4, IOPM0-7
After RE CLK 0.5 *tCLK -
tOUTh 141 Output hold time KBSOUT0-
15, IOPA0-7, IOPB0-7,
IOPC0-7, IOPD0-7, IOPF0-
7, IOPG0-7, IOPH0-7,
IOPI0-7, IOPJ0-7, IOPK0-7,
IOPL0-4, IOPM0-7
After RE CLK 0 ns
CLK
Px Input Signals
tINPs tINPh
Data In
Py Input Signals
Pz Input Signals
Figure 140. Input Signal Timing for Input and I/O Port Signals
CLK
Px Output Signals
tOUTv
tOUTh
Data Out
Pw Output Signals
Pz Output Signals
Figure 141. Output Signal Timing for Output and I/O Port Signals
7.0 Device Specifications (Continued)
www.national.com 394 Revision1.07
PC87591E/S/L
7.6.6 PWM Timing
Figure 142. Output Signal Timing for PWM Signals
7.6.7 MSWC Timing
Figure 143. Wake-Up Timing
Symbol Figure Description Reference Conditions Min Max Unit
tOUTv 142 Output valid time After RE CLK 0.5 *tCLK -
tOUTh 142 Output hold time After RE CLK 0 ns
Symbol Figure Description Reference Conditions Min Max Unit
twupd 143 Wake-up propagation delay After FE RI2,1 30 ns
tL143 RI2,1 and RING Low Time 10 ns
tH143 RI2,1 and RING High Time 10 ns
CLK
PWM0-7
tOUTv
tOUTh
Data Out
RING, RI1, RI2
PWUREQ, SMI
twupd
tLtH
7.0 Device Specifications (Continued)
Revision 1.07 395 www.national.com
PC87591E/S/L
7.6.8 PS/2 Interface Timing
Figure 144. PS/2 Receive Timing
Symbol Figure Description Reference Conditions Min Max Unit
PS/2 Input Timing
tPSDIs 144 Input setup time PSDAT1-3 Before FE PSCLK1-3 0 ns
tPSDIh 144 Input hold time PSDAT1-3 After RE PSCLK1-3 0 ns
tPSCLKl 144 PSCLK1-3 low time At 0.8V (Both Edges) (n+1)tCLK1ns
1. ‘n’ is the number of clock cycles, as programed in the IDB field. See “PS/2 Control Register (PSCON)” on
page 130.
-
tPSCLKh 144 PSCLK1-3 high time At 2.0V (Both Edges) (n+1)tCLK1ns -
PS/2 Output Timing
tPSDOv 145 Output valid time
PSDAT1-4 After FE PSCLK1-4 (n+ 6)*tCLK
+14
2ns
2. ‘n’ is defined in “PS/2 Control Register (PSCON)” on page 130.
-
tPSDOh 145 Output hold time PSDAT1-4 After FE PSCLK1-4 0 ns
tPSCLKa 146 Output active time PSCLK1-4 After RE CLK 17 ns
tPSCLKia 146 Output inactive time
PSCLK1-4 After RE CLK 17 ns
PSDAT1-4
PSCLK1-4
tPSDIs
tPSCLKl
tPSDIh
tPSCLKh
7.0 Device Specifications (Continued)
www.national.com 396 Revision1.07
PC87591E/S/L
Figure 145. PS/2 Transmit Timing
Figure 146. PS/2 Clock Signal Pulled Low by PC87591x
7.6.9 ACCESS.bus Timing
Symbol Figure Description Reference Conditions Min Max Unit
ACB Input Timing
tBUFi 148 Bus free time between Stop
and Start condition tSCLhigho -
tCSTOsi 148 SCL setup time Before Stop condition 8 *tCLK
tSCLri
-
tCSTRhi 148, 149 SCL hold time After Start condition 8 *tCLK
tSCLri
-
tCSTRsi 149 SCL setup time Before Start condition 8 *tCLK
tSCLri
-
tDHCsi 149 Data high setup time Before SCL RE 2 *tCLK -
tDLCsi 148 Data low setup time Before SCL RE 2 *tCLK -
tSCLfi 147 SCL signal fall time 300 ns
tSCLri 147 SCL signal rise time 1 µs
tSCLlowi 150 SCL low time After SCL FE 16 *tCLK -
PSDAT1-4
PSCLK1-4
tPSDOv
tPSCLKl tPSCLKh
tPSDOh
PSCLK1-4
CLK
tPSCLKa tPSCLKia
7.0 Device Specifications (Continued)
Revision 1.07 397 www.national.com
PC87591E/S/L
tSCLhighi 150 SCL high time After SCL RE 16 *tCLK -
tSDAri 147 SDA signal fall time 300 ns
tSDAfi 147 SDA signal rise time 1 µs
tSDAhi 150 SDA hold time After SCL FE 0 ns
tSDAsi 150 SDA setup time Before SCL RE 2 *tCLK -
ACB Output Timing
tSCLhigho 150 SCL high time After SCL RE K *tCLK 1
µs-
tSCLlowo 150 SCL low time After SCL FE K *tCLK 1
µs-
tBUFo 148 Bus free time between Stop
and Start condition tSCLhigho -
tCSTOso 148 SCL setup time Before Stop condition tSCLhigho -
tCSTRho 148, 149 SCL hold time After Start condition tSCLhigho -
tCSTRso 149 SCL setup time Before Start condition tSCLhigho -
tDHCso 149 Data high setup time Before SCL RE tSCLhigho
tSDAro
-
tDLCso 148 Data low setup time Before SCL RE tSCLhigho
tSDAfo
-
tSCLfo 147 SDA signal fall time 300 ns
tSCLro 147 SDA signal rise time See note1
tSDAfo 147 SDA signal fall time 300 ns
tSDAro 147 SDA signal rise time See note1-
tSDAho 150 SDA hold time After SCL FE 7 *tCLK
tSCLfo
-
tSDAvo 150 SDA valid time After SCL FE 7 *tCLK +
tSDAro
-
1. Depends on the signal’s capacitance and the pull-up value. Must be less than 1 µs.
Symbol Figure Description Reference Conditions Min Max Unit
7.0 Device Specifications (Continued)
www.national.com 398 Revision1.07
PC87591E/S/L
In Figure 147 through Figure 150, an “o” is added to parameter names in the timing tables for output signals and an “i” for
input signals, as displayed in the preceding table:
Figure 147. ACB Signals (SDA and SCL) Rising Time and Falling Time
Figure 148. ACB Start and Stop Condition Timing
Figure 149. ACB Start Condition TIming
SDA1-2
tSDAro
0.7 VCC
0.3 VCC
tSDAfi
0.7 VCC
0.3 VCC
SCL1-2
tSCLri
0.7 VCC
0.3 VCC
tSCLfi
0.7 VCC
0.3 VCC
tSDAfo
tSDAri
tSCLro tSCLfo
SDA1-2
SCL1-2
tCSTOso tBUFo
tDLCso
tCSTRho
Start Condition
Stop Condition
tCSTOsi tBUFi tCSTRhi
tDLCsi
SDA 1-2
SCL 1-2
tCSTRso
tDHCso
Start Condition
tCSTRho
tCSTRhi
tCSTRsi
tDHCsi
7.0 Device Specifications (Continued)
Revision 1.07 399 www.national.com
PC87591E/S/L
Figure 150. ACB Data Bit Timing
7.6.10 MFT16 Timing
Figure 151. Multi-Function Timer (MFT16) Input Timing
Figure 152. Multi-Function Timer (MFT16) Output Timing
Symbol Figure Description Reference Conditions Min Max Unit
MFT16 Input Timing
tTABH 151 TA1-2/TB1-2 high time tCLK + 5 ns -
tTABL 151 TA1-2/TB1-2 low time tCLK + 5 ns -
Symbol Figure Description Reference Conditions Min Max Unit
tOUTv 152 Output valid time After RE CLK 0.5 *tCLK -
tOUTh 152 Output hold time After RE CLK 0 ns
SDA 1-2
SCL 1-2
tSCLhigho
tCSLlowo
tSDAho
tSDAvo tSDAsi
tSCLhighi
tCSLlowi
tSDAhi
TA1-2/TB1-2
tTABL tTABH
CLK
TA1-2
tOUTv
tOUTh
7.0 Device Specifications (Continued)
www.national.com 400 Revision1.07
PC87591E/S/L
7.6.11 ICU/Development Timing
Figure 153. Pipe Status Signal (PFS and PLI) Timing
Figure 154. Reset Out Signal Timing
Symbol Figure Description Reference Conditions Min Max Unit
ICU/Development Input Timing
tBRKLs 153 Input setup time for BRKL Before RE CLK 10 ns
tBRKLh 153 Input hold time for BRKL After RE CLK 0 ns
ICU/Development Output Timing
tPFSh 153 Output hold time
PFS, PLI After RE CLK 0.5 *tCLK
6ns -
tPFSv 153 Output active/inactive time
PFS, PLI After RE CLK 0.5 *tCLK +
12 ns -
tRSTOd 154 Output delay time RSTO After RE Internal Reset 5 *tCLK -
tRSTOw 154 Output pulse width RSTOFEtoRERSTO3
*tCLK -
tRSTOs 154 Output inactive time RSTO Before FE Internal Reset 0 ns
CLK
tPFSv
PFS tPFSv
tPFSv
PLI
tPFSh
tPFSv
tPFSh
tBRKLs tBRKLh
BRKL_RSTO
BRKL_RSTO
Internal
Reset
Hi-Z Hi-Z
SELIO,
SEL0, SEL1
tRSTOd tRSTOw tRSTOs
7.0 Device Specifications (Continued)
Revision 1.07 401 www.national.com
PC87591E/S/L
7.6.12 Asynchronous Edge Detected Signals Timing
Figure 155. ISE, PFAIL, EXINTn and MIWU Input Signal Timing
Symbol Figure Description Reference Conditions Min Max Unit
tasw 155 Wake-up Input Width:
EXWINT20-24,
EXWINT(40,45-46)
KBSIN0-7, PFAIL
PSCLK1-4, PSDAT1-4,
SWIN
Pulse width that guarantees
detection on edge 15 ns
tis 155 Input setup time:
EXWINT20-24,
EXWINT(40,45-46, PFAIL,
PSCLK1-4, PSDAT1-4,
SWIN
See note1
1. All wake-ups are asynchronous. Meeting the setup and hold are required for repeatability of the wake cycle
only.
10 ns
tih 155 Input hold time:
EXWINT20-24,
EXWINT(40,45-46), PFAIL,
PSCLK1-4, PSDAT1-4,
SWIN
See note10ns
CLK
PFAIL tIh
tIs tasw
EXWINT20-24
SWIN
EXWINT45,46
PSCLK1-4
KBSIN0-7
PSDAT1-4
7.0 Device Specifications (Continued)
www.national.com 402 Revision1.07
PC87591E/S/L
7.6.13 Debugger Interface Timing
Figure 156. Debugger I/F Setup Time, Hold Time and Recovery Time
Figure 157. TCK Pulse Width
Symbol Figure Description Reference Conditions Min Max Unit
Debugger Interface Input Signals
tS156 TMS Setup Time Before RE TCK 7 ns
tH156 TMS Hold Time After RE TCK 2 ns
tS156 TDI Setup Time Before RE TCK 1 ns
tH156 TDI Hold Time After RE TCK 3.5 ns
tHW 157 TCK High Pulse Width 15 ns
tLW 157 TCK Low Pulse Width 5 ns
fMAX Maximum TCK Clock
Frequency 20 MHz
Tpu 129 Wait Time Power-Up to TCK tIRST1
1. See Section 7.6.2 on page 384.
-
Debugger Interface Output Signals
tPLH
tPLL
158 Propagation Delay TCK to
TDO After FE TCK 3
322
22 ns
tPLZ
tPHZ
160
159 Disable Time TCK to TDO 2
222
22 ns
tPZL
tPZH
160
159 Enable Time TCK to TDO 3
322
22 ns
tTINTh 161 TINT hld time After FE TCK 10 ns
tTINTv 161 TINT valid time After RE CLK 25 ns
TMS, TDI
TCK
tS
1.5V
tH
1.5V
TCK LOW-HIGH-LOW PULSE
TCK HIGH-LOW-HIGH PULSE
tHW, tLW
1.5V
1.5V
7.0 Device Specifications (Continued)
Revision 1.07 403 www.national.com
PC87591E/S/L
Figure 158. Debugger Interface Propagation Delay
Figure 159. TDO TRI-STATE Output High Enable and Disable Times
Figure 160. TDO TRI-STATE Output Low Enable and Disable Times
Figure 161. TINT Output Timing
TCK
tPLH, tPLL
TDO 1.5V
1.5V
TCK
TDO
tPZH
VOH
VOH 0.3V
tPHZ
1.5V
TCK
TDO
tPZL
VOL
VOL+0.3V
tPLZ
1.5V
TCK
TINT
CLK
VOL
VOL+0.3V
tTINTv tTINTh
7.0 Device Specifications (Continued)
www.national.com 404 Revision1.07
PC87591E/S/L
7.6.14 USART Timing
Figure 162. USART Asynchronous Mode Timing
Symbol Figure Description Reference Conditions Min Max Unit
tr162 CMOS output rise time. Note 1
1. Not tested; guaranteed by characterization.
6ns
tf162 CMOS output fall time. Note 16ns
tCOh2 163 Output hold (synchr. mode) After RE USCLK (2tCLK
+10 ns) -
tCOv2 163 Output valid (synchr. mode) After RE USCLK 2tCLK
+10 ns -
tCOh 162 Output hold (synchr. mode) After RE USCLK 20 ns
tIs 162 Input setup time
(asynchr. mode) Before RE CLK 15 ns
tIh 162 Input hold time
(asynchr. mode) After RE CLK 0 ns
tCLKX 162 USCLK input period (synchr.
mode) 250 ns
tCLKh 162 USCLK input low time. 2tCLK -
tCLKl 162 USCLK input high time. 2tCLK -
tSIs 163 Input Setup time (synchr.
mode) Before FE USCLK (in)
in synchronous mode tCLK +
10 ns -
tSIh 163 Input Hold time (synchr.
mode) After FE USCLK (in)
in synchronous mode tCLK +
10 ns -
tSIs1 164 Input Setup time (synchr.
mode) Before FE USCLK (out)
in synchronous mode 20 ns
tSIh1 164 Input Hold time (synchr.
mode) After FE USCLK (out)
in synchronous mode 20 ns
CLK
121212121212
tIS
tIH
tCOv tCOv
Output Signals:
UTXD
USCLK
Input Signals:
URXD
USCLK (In)
tr
tf
7.0 Device Specifications (Continued)
Revision 1.07 405 www.national.com
PC87591E/S/L
Figure 163. USART Synchronous Mode Timing (USCLK Input)
Figure 164. USART Synchronous Mode Timing (USCLK Out)
Figure 165. USART Synchronous Mode Timing (USCLK)
USCLK (In)
UTXD
tCLKX
tCOh2
tSIs
tSIh
tCLKXh
tCLKXl
URXD
tCOv2
USCLK (Out)
tCOv3
tSIs1
tSIh1
UTXD
URXD
USCLK
URXD
tSIs1
tSIh1
7.0 Device Specifications (Continued)
www.national.com 406 Revision1.07
PC87591E/S/L
7.6.15 LCLK and RESET1-2
Figure 166. LCLK Waveform
Symbol Parameter Min Max Units
tCYC1
1. The PCI may have any clock frequency between nominal DC and 33 MHz. Device operational parameters at fre-
quencies under 16 MHz may be guaranteed by design rather than by testing. The clock frequency may be
changed at any time during the operation of the system as long as the clock edges remain “clean” (monotonic)
and the minimum cycle and high and low times are not violated. The clock may only be stopped in a low state.
LCLK Cycle Time 30 ns
tHIGH LCLK High Time 11 ns
tLOW LCLK Low Time 11 ns
-LCLK Slew Rate2
2. Rise and fall times are specified in terms of the edge rate measured in V/ns. This slew rate must be met across
the minimum peak-to-peak portion of the clock wavering as shown below.
1 4 V/ns
-RESET1-2 Slew Rate3
3. The minimum RESET1-2 slew rate applies only to the rising (de-assertion) edge of the reset signal, and ensures
that system noise cannot render an otherwise monotonic signal to appear to bounce in the switching range.
50 mV/ns
0.6 VDD
0.2 VDD
0.5 VDD
0.4 VDD
0.3 VDD
0.4 VDD P-to-P
(minimum)
tHIGH tLOW
tCYC
7.0 Device Specifications (Continued)
Revision 1.07 407 www.national.com
PC87591E/S/L
7.6.16 LPC and SERIRQ Signals
Figure 167. LPC/SERIRQ Interface Output Timing
Figure 168. LPC/SERIRQ Interface Input Timing
-
Symbol Figure Description Reference Conditions Min Max Unit
tVAL 167 Output Valid Delay After RE CLK 11 ns
tON 167 Float to Active Delay After RE CLK 2 ns
tOFF 167 Active to Float Delay After RE CLK 28 ns
tSU 168 Input Setup Time Before RE CLK 7 ns
tHI 168 Input Hold Time After RE CLK 0 ns
Leakage Only
Leakage Only
0.285 VDD
0.615 VDD
0.4 VDD 0.4 VDD
LCLK
LAD3-LAD0,
LDRQ, SERIRQ
Outputs
tVAL
tON tOFF
VDD = 3.3V
tVAL
LAD3-LAD0,
SERIRQ Output Enabled
0.4 VDD
0.4 VDD
LCLK
LAD3-LAD0, LFRAME
RESET1-2,
LPCPD
, SERIRQ
Inputs
VDD = 3.3V
tHI
tSU
www.national.com 408 Revision1.07
PC87591E/S/L
A. Software for Hardware Interface
A.1 CORE DOMAIN REGISTER LIST
Module Register Name Size Register
Address Access Type Value After
Reset Comments
A.1.1 Module Configuration
(Section 2.3 on page 53 and Section 2.4.2 on page 58)
EICFG Byte 00 FF0016 Read/Write 0016
IOEE1 Byte 00 FF0216 Read/Write 0016
IOEE2 Byte 00 FF0416 Read/Write 0016
MCFG Byte 00 FF1016 Read/Write 0016 or 8016
MCFGSH Byte 00 FBFE16 Write Only MCFG shadow
STRPST Byte 00 FF1216 Read Only According to
external straps
A.1.2 Bus Interface Unit (BIU)
(Section 4.1.10 on page 83)
BCFG Byte 00 F98016 Read/Write 0716
IOCFG Word 00 F98216 Read/Write 069F16
SZCFG0 Word 00 F98416 Read/Write 069F16
SZCFG1 Word 00 F98616 Read/Write 069F16
SZCFG2 Word 00 F98816 Read/Write 069F16
A.1.3 DMA Controller
(Section 4.2.8 on page 92)
ADCA0 Double W. 00 FA0016 Read/Write
ADRA0 Double W. 00 FA0416 Read/Write
ADCB0 Double W. 00 FA0816 Read/Write
ADRB0 Double W. 00 FA0C16 Read/Write
BLTC0 Double W. 00 FA1016 Read/Write
BLTR0 Double W. 00 FA1416 Read/Write
CNTL0 Word 00 FA1C16 Read/Write 000016
STAT0 Byte 00 FA1E16 Read/Write 0016
ADCA1 Double W. 00 FA2016 Read/Write
ADRA1 Double W. 00 FA2416 Read/Write
ADCB1 Double W. 00 FA2816 Read/Write
Software for Hardware Interface (Continued)
Revision 1.07 409 www.national.com
PC87591E/S/L
ADRB1 Double W. 00 FA2C16 Read/Write
BLTC1 Double W. 00 FA3016 Read/Write
BLTR1 Double W. 00 FA3416 Read/Write
CNTL1 Word 00 FA3C16 Read/Write 000016
STAT1 Byte 00 FA3E16 Read Only 0016
ADCA2 Double W. 00 FA4016 Read/Write
ADRA2 Double W. 00 FA4416 Read/Write
ADCB2 Double W. 00 FA4816 Read/Write
ADRB2 Double W. 00 FA4C16 Read/Write
BLTC2 Double W. 00 FA5016 Read/Write
BLTR2 Double W. 00 FA5416 Read/Write
CNTL2 Word 00 FA5C16 Read/Write 000016
STAT2 Byte 00 FA5E16 Read Only 0016
ADCA3 Double W. 00 FA6016 Read/Write
ADRA3 Double W. 00 FA6416 Read/Write
ADCB3 Double W. 00 FA6816 Read/Write
ADRB3 Double W. 00 FA6C16 Read/Write
BLTC3 Double W. 00 FA7016 Read/Write
BLTR3 Double W. 00 FA7416 Read/Write
CNTL3 Word 00 FA7C16 Read/Write 000016
STAT3 Byte 00 FA7E16 Read Only 0016
A.1.4 General-Purpose I/O (GPIO) Ports
(Section 4.5.6 on page 119)
PADIR Byte 00 FE2016 Read/Write 0016
PADIN Byte 00 FE2216 Read Only
PADOUT Byte 00 FE2416 Read/Write
PAWPU Byte 00 FE2616 Read/Write 0016
PAALT Byte 00 FE2816 Read/Write 0016
PBDIR Byte 00 FE2A16 Read/Write 2016
PBDIN Byte 00 FE2C16 Read Only
PBDOUT Byte 00 FE2E16 Read/Write Bit 5 is 1; the
others are
undefined
PBWPU Byte 00 FE3016 Read/Write 0016
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 410 Revision1.07
PC87591E/S/L
PBALT Byte 00 FE3216 Read/Write 4016
PCDIR Byte 00 FE3416 Read/Write 0016 PC0 is reset on
VCC Power-up
and
WATCHDOG
reset only.
PCDIN Byte 00 FE3616 Read Only
PCDOUT Byte 00 FE3816 Read/Write
PCWPU Byte 00 FE3A16 Read/Write 0016
PCALT Byte 00 FE3C16 Read/Write 0016
PDDIR Byte 00 FE3E16 Read/Write 0016
PDDIN Byte 00 FE4016 Read Only
PDDOUT Byte 00 FE4216 Read/Write
PDWPU Byte 00 FE4416 Read/Write 0016
PDALT Byte 00 FE4616 Read/Write 0016
PEDIN Byte 00 FE4816 Read Only
PEWPU Byte 00 FE4A16 Read/Write 0016
PEALT Byte 00 FE4C16 Read/Write 0016
KBSIN Byte 00 FE4E16 Read Only
KBSINPU Byte 00 FE5016 Read/Write
KBSOUT Word 00 FE5216 Read/Write FFFF16
PFDIR Byte 00 FE5416 Read/Write 0016
PFDIN Byte 00 FE5616 Read Only
PFDOUT Byte 00 FE5816 Read/Write
PFWPU Byte 00 FE5A16 Read/Write 0016
PFALT Byte 00 FE5C16 Read/Write 0016
PHDIR Byte 00 FB0016 Read/Write 0016
PHDIN Byte 00 FB0216 Read Only
PHDOUT Byte 00 FB0416 Read/Write
PIDIR Byte 00 FB0616 Read/Write 0016
PIDIN Byte 00 FB0816 Read Only
PIDOUT Byte 00 FB0A16 Read/Write
PJDIR Byte 00 FB0C16 Read/Write 0016
PJDIN Byte 00 FB0E16 Read Only
PJDOUT Byte 00 FB1016 Read/Write
PKDIR Byte 00 FB1216 Read/Write 0016
PKDIN Byte 00 FB1416 Read Only
PKDOUT Byte 00 FB1616 Read/Write
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
Revision 1.07 411 www.national.com
PC87591E/S/L
PLDIR Byte 00 FB1816 Read/Write 0016
PLDIN Byte 00 FB1A16 Read Only
PLDOUT Byte 00 FB1C16 Read/Write
PMDIR Byte 00 FB1E16 Read/Write 0016
PMDIN Byte 00 FB2016 Read Only
PMDOUT Byte 00 FB2216 Read/Write
A.1.5 PS/2 Ports
(Section 4.6.5 on page 128)
PSDAT Byte 00 FE8016 Read/Write
PSTAT Byte 00 FE8216 Read Only 0016
PSCON Byte 00 FE8416 Read/Write 0016
PSOSIG Byte 00 FE8616 Read/Write 4716
PSISIG Byte 00 FE8816 Read Only
PSIEN Byte 00 FE8A16 Read/Write 0016
A.1.6 Host Interface (KBC, PM1 and PM2Channels)
(Section 5.1.4 on page 282 and Section 5.2.3 on page 290)
HICTRL Byte 00 FEA016 Read/Write 0016
HIIRQC Byte 00 FEA216 Read/Write 0716
HIKMST Byte 00 FEA416 Read/Write 0016
HIKDO Byte 00 FEA616 Write Only
HIMDO Byte 00 FEA816 Write Only
HIKMDI Byte 00 FEAA16 Read Only
HIPM1ST Byte 00 FEAC16 Varies per bit 0016
HIPM1DO Byte 00 FEAE16 Write Only
HIPM1DI Byte 00 FEB016 Read Only
HIPM1DOC Byte 00 FEB216 Write Only
HIPM1DOM Byte 00 FEB416 Write Only
HIPM1DIC Byte 00 FEB616 Read Only
HIPM1CTL Byte 00 FEB816 Read/Write 4016
HIPM1IC Byte 00 FEBA16 Read/Write 4116
HIPM1IE Byte 00 FEBC16 Read/Write 0016
HIPM2ST Byte 00 FEBE16 Varies per bit 0016
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 412 Revision1.07
PC87591E/S/L
HIPM2DO Byte 00 FEC016 Write Only
HIPM2DI Byte 00 FEC216 Read Only
HIPM2DOC Byte 00 FEC416 Write Only
HIPM2DOM Byte 00 FEC616 Write Only
HIPM2DIC Byte 00 FEC816 Read Only
HIPM2CTL Byte 00 FECA16 Read/Write C016
HIPM2IC Byte 00 FECC16 Read/Write 4116
HIPM2IE Byte 00 FECE16 Read/Write 0016
A.1.7 Multi-Function Timer (MTF16) 1
(Section 4.7.7 on page 142)
T1CNT1 Word 00 FD8016 Read/Write
T1CRA Word 00 FD8216 Read/Write
T1CRB Word 00 FD8416 Read/Write
T1CNT2 Word 00 FD8616 Read/Write
T1PRSC Byte 00 FD8816 Read/Write 0016
T1CKC Byte 00 FD8A16 Read/Write 0016
T1CTRL Byte 00 FD8C16 Read/Write 0016
T1ICTL Byte 00 FD8E16 Read/Write 0016
T1ICLR Byte 00 FD9016 Write Only
A.1.8 Multi-Function Timer (MFT16) 2
(Section 4.7.7 on page 142)
T2CNT1 Word 00 FDA016 Read/Write
T2CRA Word 00 FDA216 Read/Write
T2CRB Word 00 FDA416 Read/Write
T2CNT2 Word 00 FDA616 Read/Write
T2PRSC Byte 00 FDA816 Read/Write 0016
T2CKC Byte 00 FDAA16 Read/Write 0016
T2CTRL Byte 00 FDAC16 Read/Write 0016
T2ICTL Byte 00 FDAE16 Read/Write 0016
T2ICLR Byte 00 FDB016 Write Only
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
Revision 1.07 413 www.national.com
PC87591E/S/L
A.1.9 Timing and WATCHDOG (TWD)
(Section 4.10.3 on page 166)
TWCFG Byte 00 FEE016 Read/Write 0016
TWCP Byte 00 FEE216 Read/Write 0016
TWDT0 Word 00 FEE416 Read/Write FFFF16
T0CSR Byte 00 FEE616 Read/Write 0016
WDCNT Byte 00 FEE816 Write Only 0F16
WDSDM Byte 00 FEEA16 Write Only Write 5C16
A.1.10 Analog to Digital Converter (ADC)
(Section 4.11.6 on page 177)
ADCSTS Byte 00 FF2016 Varies per bit 0016 Bit 2 is reset on
VCC power up
reset only
ADCCNF Byte 00 FF2216 Read/Write 0016
ACLKCTL Byte 00 FF2416 Read/Write 3F16
ADLYCTL Byte 00 FF2616 Read/Write A716
TLOCOTL Byte 00 FF2816 Read/Write 7F16
ADCPINX Byte 00 FF2A16 Read/Write 0016
ADCPD Word 00 FF2C16 Read/Write
TCHANCTL Byte 00 FF3016 Varies per bit 1016
TCHANDAT Byte 00 FF3216 Read Only
VCHN1CTL Byte 00 FF3416 Varies per bit 1F16
VCHN1DAT Word 00 FF3616 Read Only
VCHN2CTL Byte 00 FF3816 Varies per bit 1F16
VCHN2DAT Word 00 FF3A16 Read Only
VCHN3CTL Byte 00 FF3C16 Varies per bit 1F16
VCHN3DAT Word 00 FF3E16 Read Only
A.1.11 Digital to Analog Converter (DAC)
(Section 4.12.5 on page 193)
DACCTRL Byte 00 FF4016 Read/Write 0016
DACDAT0 Byte 00 FF4216 Read/Write
DACDAT1 Byte 00 FF4416 Read/Write
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 414 Revision1.07
PC87591E/S/L
DACDAT2 Byte 00 FF4616 Read/Write
DACDAT3 Byte 00 FF4816 Read/Write
A.1.12 ACCESS.bus Interface (ACB) 1
(Section 4.13.8 on page 202)
ACB1SDA Byte 00 FF6016 Read/Write
ACB1ST Byte 00 FF6216 Varies per bit 0016
ACB1CST Byte 00 FF6416 Varies per bit 0016
ACB1CTL1 Byte 00 FF6616 Read/Write 0016
ACB1ADDR Byte 00 FF6816 Read/Write
ACB1CTL2 Byte 00 FF6A16 Read/Write 0016
A.1.13 ACCESS.bus Interface (ACB) 2
(Section 4.13.8 on page 202)
ACB2SDA Byte 00 FFE016 Read/Write
ACB2ST Byte 00 FFE216 Varies per bit 0016
ACB2CST Byte 00 FFE416 Varies per bit 0016
ACB2CTL1 Byte 00 FFE616 Read/Write 0016
ACB2ADDR Byte 00 FFE816 Read/Write
ACB2CTL2 Byte 00 FFEA16 Read/Write 0016
A.1.14 Analog Comparators Monitor (ACM)
(Section 4.14.5 on page 212)
ACMCTS Byte 00 FD4016 Varies per bit 0016
ACMCNF Byte 00 FD4216 Read/Write 0016
ACMTIM Byte 00 FD4416 Read/Write 3716
THRDAT Byte 00 FD4616 Read/Write 0016
CMPRES Byte 00 FD4816 Read Only
VOLDAT0 Byte 00 FD5016 Read Only
VOLDAT1 Byte 00 FD5216 Read Only
VOLDAT2 Byte 00 FD5416 Read Only
VOLDAT3 Byte 00 FD5616 Read Only
VOLDAT4 Byte 00 FD5816 Read Only
VOLDAT5 Byte 00 FD5A16 Read Only
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
Revision 1.07 415 www.national.com
PC87591E/S/L
VOLDAT6 Byte 00 FD5C16 Read Only
VOLDAT7 Byte 00 FD5E16 Read Only
A.1.15 Power Management (PM)
(Section 4.17.4 on page 237)
PMCSR Byte 00 FF8016 Read/Write 0016
A.1.16 High Frequency Clock Generator (HFCG)
(Section 4.18.7 on page 243)
HFCGCTRL1 Byte 00 FFA016 Varies per bit 0C16
HFCGML Byte 00 FFA216 Read/Write CF16
HFCGMH Byte 00 FFA416 Read/Write 0316
HFCGN Byte 00 FFA616 Read/Write 0816
HFCGIL Byte 00 FFA816 Read/Write
HFCGIH Byte 00 FFAA16 Read/Write
HFCGP Byte 00 FFAC16 Read/Write 1716
HFCGCTRL2 Byte 00 FFAE16 Varies per bit 0016
A.1.17 Development System Support
(Section 4.20.8 on page 275)
DBGCFG Byte 00 FF1616 Read/Write 0016
DBGFRZEN Byte 00 FF1816 Read/Write FF16
A.1.18 Multi-Input Wake-Up (MIWU)
(Section 4.4.3 on page 109)
WKEDG1 Byte 00 FFC016 Read/Write 0016
WKEDG2 Byte 00 FFC216 Read/Write 0016
WKEDG3 Byte 00 FFC416 Read/Write 0016
WKEDG4 Byte 00 FFC616 Read/Write 0016
WKPND1 Byte 00 FFC816 Read/Write 0016
WKPCL1 Byte 00 FFCA16 Write Only
WKPND2 Byte 00 FFCC16 Read/Write 0016
WKPCL2 Byte 00 FFCE16 Write Only
WKPND3 Byte 00 FFD016 Read/Write 0016
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 416 Revision1.07
PC87591E/S/L
WKPCL3 Byte 00 FFD216 Write Only
WKPND4 Byte 00 FFD416 Read/Write 0016
WKPCL4 Byte 00 FFD616 Write Only
WKEN1 Byte 00 FFD816 Read/Write 0016
WKEN2 Byte 00 FFDA16 Read/Write 0016
WKEN3 Byte 00 FFDC16 Read/Write 0016
WKEN4 Byte 00 FFDE16 Read/Write 0016
A.1.19 Interrupt Control Unit (ICU)
(Section 4.3.4 on page 101)
IVCT Byte 00 FE0016 Read Only 1016
NMISTAT Byte 00 FE0216 Read Only 0016
PFAIL Byte 00 FE0416 Read/Write 0016
ISTAT0 Word 00 FE0A16 Read Only 000016
ISTAT1 Word 00 FE0C16 Read Only 000016
IENAM0 Word 00 FE0E16 Read/Write 000016
IENAM1 Word 00 FE1016 Read/Write 000016
IECLR0 Word 00 FE1216 Write Only
IECLR1 Word 00 FE1416 Write Only
A.1.20 Debugger Interface
(Section 4.19.9 on page 267)
DBGRXD0 Word 00 FDC016 Read Only
DBGRXD2 Word 00 FDC216 Read Only
DBGRXD4 Word 00 FDC416 Read Only
DBGRXD6 Word 00 FDC616 Read Only
DBGRXD8 Word 00 FDC816 Read Only
DBGRXD10 Word 00 FDCA16 Read Only
DBGRXD12 Word 00 FDCC16 Read Only
DBGRXD14 Word 00 FDCE16 Read Only
DBGTXD0 Word 00 FDD016 Read/Write
DBGTXD2 Word 00 FDD216 Read/Write
DBGTXD4 Word 00 FDD416 Read/Write
DBGTXD6 Word 00 FDD616 Read/Write
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
Revision 1.07 417 www.national.com
PC87591E/S/L
DBGTXD8 Word 00 FDD816 Read/Write
DBGTXD10 Word 00 FDDA16 Read/Write
DBGTXD12 Word 00 FDDC16 Read/Write
DBGTXD14 Word 00 FDDE16 Read/Write
DBGRXST Byte 00 FDE016 Varies per bit
DBGTXST Byte 00 FDE216 Read/Write 0016
DBGTXLOC Byte 00 FDE416 Read/Write 0F16
DBGTINT Byte 00 FDE616 Write Only
DBGABORT Word 00 FDE816 Write Only
DBGISESRCA Word 00 FDEA16 Read/Write 000016
A.1.21 Pulse Width Modulator (PWM)
(Section 4.8.5 on page 148)
PRSC Byte 00 FD0016 Read/Write 0016
CTR Byte 00 FD0216 Read/Write FF16
PWMPOL Byte 00 FD0416 Read/Write 0016
PWMCNT Byte 00 FD0616 Read/Write 0016
DCR0 Byte 00 FD0816 Read/Write 0016
DCR1 Byte 00 FD0A16 Read/Write 0016
DCR2 Byte 00 FD0C16 Read/Write 0016
DCR3 Byte 00 FD0E16 Read/Write 0016
DCR4 Byte 00 FD1016 Read/Write 0016
DCR5 Byte 00 FD1216 Read/Write 0016
DCR6 Byte 00 FD1416 Read/Write 0016
DCR7 Byte 00 FD1616 Read/Write 0016
A.1.22 Universal Synchronous/Asynchronous Receiver Transmitter (USART)
(Section 4.9.4 on page 158)
UTBUF Byte 00 FD2016 Read/Write
URBUF Byte 00 FD2216 Read Only
UICTRL Byte 00 FD2416 Varies per bit 0116
USTAT Byte 00 FD2616 Read Only 0016
UFRS Byte 00 FD2816 Read/Write 0016
UMDSL Byte 00 FD2A16 Read/Write 0016
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 418 Revision1.07
PC87591E/S/L
UBAUD Byte 00 FD2C16 Read/Write 0016
UPSR Byte 00 FD2E16 Read/Write 0016
A.1.23 Flash Interface
(Section 4.16.7 on page 228)
IBAI Word 00 F88016 Read/Write
IBD Word 00 F88216 Read/Write
FCWP0 Word 00 F89016 Read/Write 000016
FLCR Word F8C016 Read/Write 000016
FLSR Byte F8C216 Varies per bit 0016
FLPSLR Byte F8C416 Read/Write 0016
FLSTART Byte F8C616 Read/Write 1416
FLTRAN Byte F8CA16 Read/Write 2816
FLPROG Byte F8D016 Read/Write 0A16
FLPERASE Byte F8D216 Read/Write 0916
FLSERASE Byte F8D416 Read/Write 0916
FLEND Byte F8D816 Read/Write 1416
FLSEND Byte F8DC16 Read/Write 3216
FLRCV Byte F8DE16 Read/Write 0416
A.1.24 Shared Memory Core
(Section 5.3.9 on page 307)
SMCCST Byte 00 F90016 Read/Write 0016
SMCTA Byte 00 F90216 Read/Write and
Read Only See description
SMHSEM Byte 00 F90416 Varies per bit 0016
SMCORP0 Word 00 F91016 Varies per bit See description
SMCORP1 Word 00 F91216 Varies per bit See description
SMCORP2 Word 00 F91416 Varies per bit See description
SMCOWP0 Word 00 F92016 Read/Write FFFF16
SMCOWP1 Word 00 F92216 Read/Write FFFF16
SMCOWP2 Word 00 F92416 Read/Write FFFF16
RNGCS Byte 00 F93016 Varies per bit 0016
RNGD Byte 00 F93216 Read Only
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
Revision 1.07 419 www.national.com
PC87591E/S/L
A.1.25 Core Access to SuperI/O
IHIOA Word 00 FCE016 Read/Write 0016
IHD Byte 00 FCE216 Read/Write 0016
LKSIOHA Word 00 FCE416 Read/Write 000216/000016
SIOLV Word 00 FCE616 R/W1C 000016
CRSMAE Word 00 FCE816 Read/Write 000016
SIBCTRL Byte 00 FCEA16 Varies per bit 0016
A.1.26 Mobile System Wake-Up Control (MSWC)
(Section 5.5.6 on page 328)
MSWCTL1 Byte 00 FCC016 Varies per bit 0016 Vcc power-up
only
MSWCTL2 Byte 00 FCC216 Varies per bit 0016
MSWCTL3 Byte 00 FCC416 Varies per bit 0116 VPP power-up
only
HCFGBAL Byte 00 FCC816 Read/Write 0016
HCFGBAH Byte 00 FCCA16 Read/Write 0016
MSIEN2 Byte 00 FCCC16 Read/Write 0016
MSHES0 Byte 00 FCCE16 R/W1C 0016
MSHEIE0 Byte 00 FCD016 Read/Write 0016
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 420 Revision1.07
PC87591E/S/L
A.2 HOST DOMAIN REGISTER LIST
A.2.1 Configuration Registers
Access to all host configuration registers is via an index/data scheme that uses the host configuration index/data pair.
A.2.2 Host Runtime Registers
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Common SuperI/O Configuration
(Section 6.1.8 on page 343)
SID Byte Index 2016 Read Only EC16
SIOCF1 Byte Index 2116 Varies per bit 1116
SIOCF5 Byte Index 2516 Read/Write 0016
SIOCF6 Byte Index 2616 Read/Write 0016
SRID Byte Index 2716 Read Only
SIOCF8 Byte Index 2816 Read/Write 0016
SIOCF9 Byte Index 2916 Read/Write 0116
SIOCFD Byte Index 2D16 Read/Write 0016
Shared Memory
(Section 6.1.11 on page 349)
SharedMemory
Configuration Byte Index F416 Read/Write 0016 or 0916
depending on
SHBM strap
SharedMemory
Base Address
High Byte Byte Index F516 Read/Write 0016
SharedMemory
Base Address
Low Byte Byte Index F616 Read/Write 0016
SharedMemory
Size Config Byte Index F716 Read/Write 0016
RTC Configuration
When LDN is set to 1016. (Section 6.1.12 on page 353)
RLR Byte Device
Specific Read/Write 0016 Cleared by H/W
reset only
DOMAO Byte Index F016 Read/Write 0016
MONAO Byte Index F116 Read/Write 0016
CENO Byte Index F316 Read/Write 0016
Software for Hardware Interface (Continued)
Revision 1.07 421 www.national.com
PC87591E/S/L
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Shared Memory Host
The base address is defined by LDN 0F16 (Section 5.3.8 on page 303).
SMIMA0 Byte Offset 0016 Read/Write
SMIMA1 Byte Offset 0116 Read/Write
SMIMA2 Byte Offset 0216 Read/Write
SMIMA3 Byte Offset 0316 Read/Write
SMIMD Byte Offset 0416 Read/Write
SMHC Byte Offset 0516 Read/Write 0016
SMHST Byte Offset 0616 Varies per bit 0016
SMHAP1 Byte Offset 0716 Varies per bit 0216
SMHAP2 Byte Offset 0816 Varies per bit 0216
SMHSEM Byte Offset 0C16 Varies per bit 0016
MSWC Host Registers
The base address is defined by LDN 0416 (Section 5.5.5 on page 323).
WK_STS0 Byte Offset 0016 R/W1C 0016
WK_EN0 Byte Offset 0216 Read/Write 0016
WK_CFG Byte Offset 0416 Read/Write 0016
WK_SIGV Byte Offset 0616 Read Only
WK_STATE Byte Offset 0716 Read/Write
WK_SMIEN0 Byte Bank 2
Offset 1316 Read/Write 0016
WK_IRQEN0 Byte Bank 2
Offset 1516 Read/Write 0016
Host Interface (HI)
The base address is defined by LDN 0616 (“Host Addresses” on page 277).
DBBOUT Byte
Defined in
LDN 0616
index 6016,
6116
R
STATUS Byte
Defined in
LDN 0616
index 6216,
6316
R0016
DBBIN Byte
Defined in
LDN 0616
index 6016,
6116
W
Software for Hardware Interface (Continued)
www.national.com 422 Revision1.07
PC87591E/S/L
COMAND Byte
Defined in
LDN 0616
index 6216,
6316
W
Power Management Channel 1
The base address is defined by LDN 1116 (“Host Addresses” on page 277).
DBBOUT Byte
Defined in
LDN 1116
index 6016,
6116
R
STATUS Byte
Defined in
LDN 1116
index 6216,
6316
R0016
DBBIN Byte
Defined in
LDN 1116
index 6016,
6116
W
COMAND Byte
Defined in
LDN 1116h
index 6216,
6316
W
Power Management Channel 2
The base address is defined by LDN 1216 (“Host Addresses” on page 277).
DBBOUT Byte
Defined in
LDN 1216
index 6016,
6116
R
STATUS Byte
Defined in
LDN 1216
index 6216,
6316
R0016
DBBIN Byte
Defined in
LDN 1216
index 6016,
6116
W
COMAND Byte
Defined in
LDN 1216
index 6216,
6316
W
RTC
Access is via a index/data scheme that uses an index/data pair pointed to by LDN 1016 (Section 6.2.15 on page 363).
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
Revision 1.07 423 www.national.com
PC87591E/S/L
SEC Byte Index 0016 Read/Write 0016
SECA Byte Index 0116 Read/Write 0016
MIN Byte Index 0216 Read/Write 0016
MINA Byte Index 0316 Read Only 0016
HOR Byte Index 0416 Read/Write 0016
HORA Byte Index 0516 Read/Write 0016
DOW Byte Index 0616 Read/Write 0016
DOM Byte Index 0716 Read/Write 0016
MON Byte Index 0816 Read/Write 0016
YER Byte Index FF16 Read/Write 0016
CRA Byte Index 0A16 Read/Write 2016
CRB Byte Index 0B16 Read/Write 0016
CRC Byte Index 0C16 Read Only 0016
CRD Byte Index 0D16 Read Only 0016
DOMA Byte Prog. Index Read/Write C016
MONA Byte Prog. Index Read/Write C016
CEN Byte Prog. Index Read/Write 0016
Module Register Name Size Register
Address Access Type Value After
Reset Comments
Software for Hardware Interface (Continued)
www.national.com 424 Revision1.07
PC87591E/S/L
A.3 CORE DOMAIN REGISTER LAYOUT
A.3.1 Module Configuration
(Section 2.3 on page 53 and Section 2.4.2 on page 58)
A.3.2 Bus Interface Unit (BIU)
(Section 4.1.10 on page 83)
A.3.3 DMA Controller
(Section 4.2.8 on page 92)
A.3.4 General-Purpose I/O (GPIO) Port
(Section 4.5.6 on page 119)
76543210
MCFG/MCFGSH GTMON Reserved CLKOM EXMEM16 ENEMEM ENEIO
EICFG Reserved EXWINT46 EXWINT45
IOEE1 Reserved EEPA4 EEPA3 EEPA2 EEPA1 EEPA0
IOEE2 Reserved EEPC0 EEPD3 EEPB2 EEPB1 EEPB0
STRPST (p. 53) Reserved Reserved Reserved Reserved Reserved BADDR1 BADDR0 SHBM
15 12 11 10 9 8 7 6 5 4 3 2 1 0
BCFG N/A Reserved ISTL OBR EWR
IOCFG Reserved IPS
TRes BW Reserved HOLD WAIT
SZCFGn Reserved FRE IPRE IPS
TRes BW WBR BRE HOLD WAIT
3
13
02
92
82
72
62
52
42
32
22
12
01
91
81
71
61
51
41
31
21
11
09876543210
ADCAn Device A Address Counter
ADRAn Device A Address
ADCBn Device B Address Counter
ADRBn Device B Address
BLTCn Reserved Block Length Counter
BLTRn Reserved Block Length
CNTLn N/A R
e
s
I
N
C
B
A
D
B
I
N
C
A
A
D
A
S
W
R
Q
B
P
CO
TD
I
R
I
N
D
T
C
S
E
O
V
R
E
T
C
C
H
E
N
STATn N/A Reserved V
L
D
C
H
A
C
O
V
RT
C
7 6 543210
PADIR PA Port Direction
PBDIR PB Port Direction
PCDIR PC Port Direction
PDDIR PD Port Direction
PFDIR PF Port Direction
PGDIR PG Port Direction
PIDIR PI Port Direction
PJDIR PJ Port Direction
PKDIR PK Port Direction
PLDIR Reserved PL Port Direction
PMDIR PM Port Direction
PADIN PA Port Input Data
PBDIN PB Port Input Data
Software for Hardware Interface (Continued)
Revision 1.07 425 www.national.com
PC87591E/S/L
A.3.5 PS/2 Interface
(Section 4.6.5 on page 128)
A.3.6 Core Interface
(Section 5.1.4 on page 282 and Section 5.2.3 on page 290)
PCDIN PC Port Input Data
PDDIN PD Port Input Data
PEDIN PE Port Input Data
PFDIN PF Port Input Data
PHDIN PH Port Input Data
PIDIN PI Port Input Data
PJDIN PJ Port Input Data
PKDIN PK Port Input Data
PLDIN Reserved PL Port Input Data
PMDIN PM Port Input Data
PADOUT PA Port Output Data
PBDOUT PB Port Output Data
PCDOUT PC Port Output Data
PDDOUT PD Port Output Data
PFDOUT PF Port Output Data
PHDOUT PH Port Output Data
PIDOUT PI Port Output Data
PJDOUT PJ Port Output Data
PKDOUT PK Port Output Data
PLDOUT Reserved PL Port Output Data
PMDOUT PM Port Output Data
PAWPU PA Port Weak Pull-up Enable
PBWPU PB Port Weak Pull-up Enable
PCWPU PC Port Weak Pull-up Enable
PDWPU PD Port Weak Pull-up Enable
PEWPU PE Port Weak Pull-up Enable Reserved PE Port
Weak Pull-
up Enable Reserved
PFWPU PF Port Weak Pull-up Enable
PAALT PA Pins Alternate Function Enable
PBALT PB Pins Alternate Function Enable
PCALT PC Pins Alternate Function Enable
PDALT PD Pins Alternate Function Enable
PEALT PE Pins Alternate Function Enable
PFALT PF Pins Alternate Function Enable
76 5 4 3 2 10
PSDAT Data
PSTAT Reserved RFERR ACH PERR EOT SOT
PSCON WPUEN IDB HDRV XMT EN
PSOSIG CLK4 WDAT4 CLK3 CLK2 CLK1 WDAT3 WDAT2 WDAT1
PSISIG RCLK4 RDAT4 RCLK3 RCLK2 RCLK1 RDAT3 RDAT2 RDAT1
PSIEN Reserved DSMIE EOTIE SOTIE
76543210
HICTRL Reserved PMICIE PMOCIE PMHIE IBFCIE OBECIE OBFMIE OBFKIE
HIIRQC Reserved IRQNPOL IRQM IRQ11B IRQ12BO
BFMIE IRQ1B
HIKMST ST3 ST2 ST1 ST0 A2 F0 IBF OBF
HIKDO Keyboard DBBOUT Data
HIMDO Mouse DBBOUT Data
HIKMDI Keyboard/Mouse DBBIN Data
7 6 543210
Software for Hardware Interface (Continued)
www.national.com 426 Revision1.07
PC87591E/S/L
A.3.7 Multi-Function Timer (MFT16)
(Section 4.7.7 on page 142)
A.3.8 Timing and WATCHDOG (TWD)
(Section 4.10.3 on page 166)
A.3.9 Analog to Digital Converter (ADC)
(Section 4.11.6 on page 177)
HIPMnST ST3 ST2 ST1 ST0 A2 F0 IBF OBF
HIPMnDO PM Channel DBBOUT Data
HIPMnDOC PM Channel DBBOUT Data
HIPMnDOM PM Channel DBBOUT Data
HIPMnDI PM Channel DBBIN Data
HIPMnDIC PM Channel DBBIN Data
HIPMnCTRL EME SCIPOL PLMS Reserved OBEIE IBFIE
HIPMnIC SCIIS SMIPOL PLMM SCIB SMIB IRQB
HIPMnIE Reserved HSMIE HSCIE HIRQE SMIE SCIE IRQE
15876543210
TnPRSC N/A Reserved CLKPS
TnCKC N/A Reserved C2CSEL C1CSEL
TnCTRL N/A Reserved TAOUT TBEN TAEN TBEDG TAEDG MDSEL
TnICTL N/A TDIEN TCIEN TBIEN TAIEN TDPND TCPND TBPND TAPND
TnICLR N/A Reserved TDCLR TCCLR TBCLR TACLR
15 8 7 6 5 4 3 2 1 0
TWCFG N/A Reserved WDSDME WDCT0I LWDCNT LTWDT0 LTWCP LTWCFG
TWCP N/A Reserved MDIV
TWDT0 Preset
T0CSR N/A Reserved WDLTD Reserved TC RST
WDCNT N/A PRESET
WDSDM N/A RSDATA
15109876543210
ADCSTS N/A Reserved OPSH-
TYPE OP-
SHEV OTSEV OVFEV EOCEV
ADCCNF N/A Reserved INTO-
SEN INTO-
TEN INTE-
CEN REM-
DEN ADCEN
ACLKCTL N/A Reserved SCLKDIV
ADLYCTL N/A TMPDLY Res VOLDLY
TLOCOTL N/A OTSLIM
ADCPINX N/A Index
ADCPD Parameter Data
TCHANCTL N/A DATVAL RDMEA
SEN INTD-
VEN SELIN
TCHANDAT N/A TCHDAT
VCHN1CTL N/A DATVAL CSCALE INTD-
VEN SELIN
VCHN1DAT Reserved VCHDAT
VCHN2CTL N/A DATVAL CSCALE INTD-
VEN SELIN
VCHN2DAT Reserved VCHDAT
VCHN3CTL N/A DATVAL CSCALE INTD-
VEN SELIN
VCHN3DAT Reserved VCHDAT
76543210
Software for Hardware Interface (Continued)
Revision 1.07 427 www.national.com
PC87591E/S/L
A.3.10 Digital to Analog (DAC)
(Section 4.12.5 on page 193)
A.3.11 ACCESS.bus Interface (ACB)
(Section 4.13.8 on page 202)
A.3.12 Analog Comparators Monitor (ACM)
(Section 4.14.5 on page 212)
A.3.13 Power Management (PM)
(Section 4.17.4 on page 237)
A.3.14 High-Frequency Clock Generator (HFCG)
(Section 4.18.7 on page 243)
A.3.15 Development System Support
(Section 4.20.8 on page 275)
A.3.16 Multi-Input Wake-Up (MIWU)
(Section 4.4.3 on page 109)
76543210
DACCTRL Reserved ENIDLE DACEN3 DACEN2 DACEN1 DACEN0
DACDATi DAC DATAi
765432 1 0
ACBnSDA DATA
ACBnST SLVSTP SDAST BER NEGACK STASTR NMATCH MASTER XMIT
ACBnCST ARP-
MATCH MATCHAF TGSCL TSDA GMATCH MATCH BB BUSY
ACBnCTL1 STASTRE NMINTE GCMEN ACK Reserved INTEN STOP START
ACBnADDR SAEN ADDR
ACBnCTL2 SCLFRQ6 SCLFRQ5 SCLFRQ4 SCLFRQ3 SCLFRQ2 SCLFRQ1 SCLFRQ0 ENABLE
765432 1 0
ACMCTS Reserved OVUNTHEV EOCEV EOMEV START
ACMCNF Reserved OVUNSEL INTOUEN INTEMEN Reserved ACMMOD
ACMTIM Reserved T0DIV Reserved SMPDLY
THRDAT Reserved THRSHD5 THRSHD4 THRSHD3 THRSHD2 THRSHD1 THRSHD0
CMPRES CMPIN7 CMPIN6 CMPIN5 CMPIN4 CMPIN3 CMPIN2 CMPIN1 CMPIN0
VOLDAT0-7 Reserved Voltage Level Data 5-0
76 5 4 3210
PMCSR OLFC OHFC WBPSM Reserved IDLE DHF Reserved
7 65432 1 0
HFCGCTRL1 Reserved FAST96 LOAD96 IVLID OHFC PENABLE FAST LOAD
HFCGML HFCGM7-0
HFCGMH HFCGM
HFCGN Reserved HFCGN4-0
HFCGIL HFCGI7-0
HFCGIH Reserved HFCGI13-8
HFCGP Reserved HFCGP4-0
HFCGCTRL2 Reserved 96MON MONERR SCESTP SCESTR SENABLE
76543210
DBGCFG Reserved BRKLE FREEZE ON
DBGFRZEN Reserved HIFEN USARTFEN ACB2FEN ACB1FEN MFT2FEN MFT1FEN
765 4 3 2 10
Software for Hardware Interface (Continued)
www.national.com 428 Revision1.07
PC87591E/S/L
A.3.17 Interrupt Control Unit (ICU)
(Section 4.3.4 on page 101)
A.3.18 Debugger Interface
(Section 4.19.9 on page 267)
WKEDG1 WKED17 WKED16 WKED15 WKED14 WKED03 WKED12 WKED11 WKED10
WKEDG2 WKED27 WKED26 WKED25 WKED24 WKED23 WKED22 WKED21 WKED20
WKEDG3 WKED37 WKED36 WKED35 WKED34 WKED33 WKED32 WKED31 WKED30
WKEDG4 WKED47 WKED46 WKED45 WKED44 WKED43 WKED42 WKED41 WKED40
WKPND1 WKPD17 WKPD16 WKPD15 WKPD14 WKPD03 WKPD12 WKPD11 WKPD10
WKCL1 WKCL17 WKCL16 WKCL15 WKCL14 WKCL03 WKCL12 WKCL11 WKCL10
WKPND2 WKPD27 WKPD26 WKPD25 WKPD24 WKPD23 WKPD22 WKPD21 WKPD20
WKCL2 WKCL27 WKCL26 WKCL25 WKCL24 WKCL23 WKCL22 WKCL21 WKCL20
WKPND3 WKPD37 WKPD36 WKPD35 WKPD34 WKPD33 WKPD32 WKPD31 WKPD30
WKCL3 WKCL37 WKCL36 WKCL35 WKCL34 WKCL33 WKCL32 WKCL31 WKCL30
WKPND4 WKPD47 WKPD46 WKPD45 WKPD44 WKPD43 WKPD42 WKPD41 WKPD40
WKCL4 WKCL47 WKCL46 WKCL45 WKCL44 WKCL43 WKCL42 WKCL41 WKCL40
WKEN1 WKEN17 WKEN16 WKEN15 WKEN14 WKEN13 WKEN12 WKEN11 WKEN10
WKEN2 WKEN27 WKEN26 WKEN25 WKEN24 WKEN23 WKEN22 WKEN21 WKEN20
WKEN3 WKEN37 WKEN36 WKEN35 WKEN34 WKEN33 WKEN32 WKEN31 WKEN30
WKEN4 WKEN47 WKEN46 WKEN45 WKEN44 WKEN43 WKEN42 WKEN41 WKEN40
1512118765432 1 0
IVCT N/A 0 0 INTVECT
NMISTAT N/A Reserved EXT
PFAIL N/A Reserved ENLCK PIN EN
ISTAT0 Interrupt Status Register (15-0)
ISTAT1 Interrupt Status Register (31-16)
IENAM0 Interrupt Enable (15-0)
IENAM1 Interrupt Enable (31-16)
158765432 1 0
DBGRXD0 RX_Data0
DBGRXD2 RX_Data2
DBGRXD4 RX_Data4
DBGRXD6 RX_Data6
DBGRXD8 RX_Data8
DBGRXD10 RX_Data10
DBGRXD12 RX_Data12
DBGRXD14 RX_Data14
DBGTXD0 TX_Data0
DBGTXD2 TX_Data2
DBGTXD4 TX_Data4
DBGTXD6 TX_Data6
DBGTXD8 TX_Data8
DBGTXD10 TX_Data10
DBGTXD12 TX_Data12
DBGTXD14 TX_Data14
DBGRXST N/A MSG_LEN PID RX_BUSY
DBGTXST N/A Reserved MSG_LEN
DBGTXLOC N/A Reserved PID
DBGTINT N/A Reserved ASSERT
DBGABORT Reserved P_0
DBGISESRCA Reserved ABORT_0 RX_0
Software for Hardware Interface (Continued)
Revision 1.07 429 www.national.com
PC87591E/S/L
A.3.19 Pulse with Modulator (PWM)
(Section 4.8.5 on page 148)
A.3.20 Universal Synchronous/Asynchronous Receiver Transmitter (USART)
(Section 4.9.4 on page 158)
A.3.21 Flash Interface
(Section 4.16.7 on page 228)
A.3.22 Shared Memory Core
(Section 5.3.9 on page 307)
765 4 3 2 10
PRSC PRSC(7-0)
CTR CTR(7-0)
PWMPOL INVP(7-0)
PWMCNT Reserved PWR
DCRi DCRi(7-0)
765 4 3 2 10
UTBUF UTBUF
URBUF URBUF
UICTRL EEI ERI ETI Reserved Reserved Reserved RBF TBE
USTAT Reserved XMIP RB9 BKD ERR DOE FE PE
UFRS Reserved PEN PSEL XB9 STP CHAR
UMDSL Reserved Reserved ERD ETD CKS BRK UnATN MOD
UBAUD UDIV(7-0)
UPSR UPSC UDIV(10-8)
15 9 8 7 6 5 4 3 2 1 0
IBAI Reserved Indirect Memory Address (7-0)
IBD Information Block Data
FCWP0 FC0WP(15-0)
FCWP1 FC1WP(15-0)
FCWP2 FC2WP(15-0)
FLCR Res DIS-
VRF SMER PMER PE IENPROG Reserved LOWP-
WRS LOWP-
WRF
FLSR N/A Reserved DERR FMLFULL FMBUSY PERR EERR
FLPSLR N/A Reserved FTDIV(3-0)
FLSTART N/A FTSTART(7-0)
FLTRAN N/A FTTRAN(7-0)
FLPROG N/A FTPROG(7-0)
FLPERASE N/A FTPER(7-0)
FLSERASEi N/A FTSER(7-0)
FLEND N/A FTEND(7-0)
FLSEND N/A FTSEND(7-0)
FLRCV N/A FTRCV(7-0)
15 8 7 6 5 4 3 2 1 0
SMCCST N/A HSEMIE HSEMW HLOCK HERES HERRIEN HWERR HRERR
SMCTA N/A Reserved MBSD
SMHSEM N/A CSEM3 CSEM2 CSEM1 CSEM0 HSEM3 HSEM2 HSEM1 HSEM0
SMCOHRP0 ORPLA(15-0)
SMCOHRP1 ORP(15-2) Reserved
SMCOHRP2 ORP(31-16)
SMCOHWP0 OWPLA(15-0)
SMCOHWP1 OWP(15-2) Reserved
SMCOHWP2 OWP(31-16)
Software for Hardware Interface (Continued)
www.national.com 430 Revision1.07
PC87591E/S/L
A.3.23 Core Access to SuperI/O
(Section 5.4.1 on page 314)
A.3.24 MSWC
(Section 5.5.6 on page 328)
RNGCS N/A Reserved CLKP DVALID RNGE
RNGD N/A RNGD(0-7)
15 8 7 6 5 4 3 2 1 0
IHIOA Reserved Indirect Host I/O Offset
IHD N/A Indirect Host Data
LKSIOHA Reserved LKRTCHA LKCFG
SIOLV Reserved RTCLV CFGLV
CRSMAE Reserved RTCAE CFGAE
SIBCTRL N/A Reserved RTCMR CSWR CSRD CSAE
765 4 3 2 10
MSWCTL1 Reserved HSECM VHCFGLK VHCFGA LPCRSTA HPWRON HRSTOB
MSWCTL2 CFGPSO CFGPBM ACPIS5 ACPIS4 ACPIS3 ACPIS2 ACPIS1 ACPIS0
MSWCTL3 Reserved RTCAL LPFTO HRAPU
HCFGBAL Host Configuration Registers Base Address Low
HCFGBAH Host Configuration Registers Base Address High
MSIEN2 EICFGPSO EICFG-
PBM EIACPIS5 EIACPIS4 EIACPIS3 EIACPIS2 EIACPIS1 EIRTCAL
MSHES0 Module
IRQ Event
Status
Software
Event Sta-
tus Reserved RINGEvent
Status Reserved RI2 Event
Status RI1 Event
Status
MSHEIE0 Module
IRQ Event
Enable
Software
Event
Enable Reserved RINGEvent
Enable Reserved RI2 Event
Enable RI1 Event
Enable
15 8 7 6 5 4 3 2 1 0
Software for Hardware Interface (Continued)
Revision 1.07 431 www.national.com
PC87591E/S/L
A.4 HOST DOMAIN REGISTER LAYOUT
Host Configuration Registers
A.4.1 SuperI/O Configuration
(Section 6.1.8 on page 343)
A.4.2 Shared Memory Configuration
(Section 6.1.11 on page 349)
A.4.3 RTC Configuration
(Section 6.1.12 on page 353)
Host Runtime Registers
A.4.4 Shared Memory Host
(Section 5.3.8 on page 303)
7 6543210
SID Family ID
SIOCF1 Reserved Number of DMA Wait
States Number of I/O Wait
States Software
Reset SuperI/O
Devices
Enable
SIOCF5 Reserved SMItoIRQ2
Enable Reserved
SIOCF6 SCIOF6 Soft-
ware Lock General-Purpose
Scratch RTC
Disabled Reserved
SRID Chip Revision ID
SIOCF8 Reserved LPC Bus Master Num. Reserved
SIOCF9 Reserved Module
Enable
Status
Valid Multi-
plier Clock
Status Clock
Enable SuperI/O Clock Domain
Source
SIOCFD Reserved Power
Supply Off Power But-
ton Mode
7 6543210
Shared Memory
Configuration BIOS FWH ID BIOS FWH
Enable
User-De-
fined Mem-
ory Space
Enable
BIOS Ex-
tended
Space En-
able
BIOS LPC
Enable
Shared Memory
Base Address
High Byte User-Defined Memory Zone Address High
Shared Memory
Base Address
Low Byte User-Defined Memory Zone Address Low
Shared Memory
Size Configuration Reserved User-Defined Memory Zone Size
7 6543210
RLR Block
Standard
RAM Block
RAM Write Block
Extended
RAM Write
Block
Extended
RAM Read
Block
Extended
RAM Reserved
DOMAO Reserved Date of Month Alarm Register Offset Value
MONAO Reserved Month Alarm Register Offset Value
CENO Reserved Century Register Offset Value
7 6543210
SMIMA0 Indirect Memory Address (7-0)
SMIMA1 Indirect Memory Address (15-8)
SMIMA2 Indirect Memory Address (23-16)
Software for Hardware Interface (Continued)
www.national.com 432 Revision1.07
PC87591E/S/L
A.4.5 MSWC Host
(Section 5.5.5 on page 323)
A.4.6 Host Interface (HI) Registers
(“Host Addresses” on page 277)
A.4.7 RTC Registers
(Section 6.2.15 on page 363)
SMIMA3 Indirect Memory Address (31-24)
SMIMD Indirect Memory Data (7-0)
SMHC Reserved PMER Reserved
SMHST Reserved HDERR FMLFULL HBUSY HPERR HEERR
SMHAP1,2 Host Access Protection Index Index Write Host Lock
Protection Host Write
Protection Host Read
Protection
SMHSEM CSEM3 CSEM2 CSEM1 CSEM0 HSEM3 HSEM2 HSEM1 HSEM0
7 6543210
WK_STS0 Module IRQ
Event Status Software
Event Sta-
tus Reserved RING
Event
Status Reserved RI2 Event
Status RI1 Event
Status
WK_EN0 Module IRQ
Event Enable Software
Event
Enable Reserved RING
Event
Enable Reserved RI2 Event
Enable RI1 Event
Enable
WK_CFG Reserved Configuration Bank
Select
WK_SIGV Reserved PWUREQ
Wakeup
or IRQ
PWUREQ
Output
Value PM2 SMI
Output PM1 SMI
Output SMI Wake-
up Output SMIOutput
Value
WK_STATE Reserved S5 S4 S3 S2 S1 Reserved
WK_SMIEN0 Reserved Software
Event to
SMI
Enable Reserved Ring Event
to SMI
Enable Reserved RI2 Event
to SMI
Enable
RI1 Event
to SMI
Enable
WK_IRQENO Reserved Software
Event to
IRQ
Enable Reserved Ring Event
to IRQ
Enable Reserved RI2 Event
to IRQ
Enable
RI1 Event
to IRQ
Enable
76543210
DBBOUT Keyboard/Mouse DBBOUT Data
STATUS ST3 ST2 ST1 ST0 A2 F0 IBF OBF
DBBIN Keyboard/Mouse DBBIN Data
COMAND Keyboard/Mouse DBBIN Data
7 6543210
SEC Seconds Data
SECA Seconds Alarm Data
MIN Minutes Data
MINA Minutes Alarm Data
HOR Hours Data
HORA Hours Alarm Data
DOW Day of Week Data
DOM Date of Month Data
MON Month Data
YER Year Data
CRA Update in
Progress Divider Chain Control 2-0 Periodic Interrupt Rate Select 3-0
Software for Hardware Interface (Continued)
Revision 1.07 433 www.national.com
PC87591E/S/L
CRB Set Mode Periodic
Interrupt
Enable
Alarm
Interrupt
Enable
Update
Ended
Interrupt
Enable Reserved Data Mode Hour Mode Daylight
Savings
CRC IRQ Flag Periodic
Interrupt
Flag
Alarm
Interrupt
Flag
Update
Ended
Interrupt
Flag Reserved
CRD Valid RAM
and Time Reserved
DOMA Date of Month Alarm Data
MONA Month Alarm Data
CEN Century Data
www.national.com 434 Revision1.07
PC87591E/S/L
B. Software for Hardware Interface
B.1 FACTORY PARAMETERS
The following table is stored in the factory parameters section of the flash.
RevisionCode Interpretation
00xx16 - Pre-production versions; contact NSC for usage guidelines.
01xx16 - Production version xx of PC87591x devices (xx is a version number starting with 0x00).
02xx16 - Production version xx of PC87591x devices with special handling noted in user information.
FFxx16 - A non-tested device; contact National Semiconductor for usage guidelines.
Other - Reserved for future use.
The ADC should be initialized after reset with the factory parameters setting that are stored in flash memory. The code below
is an example of how the data may be loaded into the ADC.
#define IBAI (*((volatile unsigned short *)0xF880))
#define IBD (*((volatile unsigned short *)0xF882))
#define ADCPINX (*((volatile unsigned char*)0xFF2A))
#define ADCPD (*((volatile unsigned int *)0xFF2C))
void CalibrateADC()
{unsigned int i, count;
IBAI = 0x0000; // Set address to RevisionCode
if ( (IBD & 0xff00) == 0x0100) // Check that RevisionCode is 0x01yy;
// refer to user information on
// other cases.
{ // Factory Parameters are programed with the correct version
IBAI= 0x0002; // Set address to ‘count’
count = IBD; // Read the number of elements to copy
for (i=1; i<= count ; i++)
{ADCPINX = (unsigned char)i; // Set pointer in ADC register
IBAI = 2*i+2; // Set pointer in Flash
ADCPD = IBD; // Copy from flash to ADC register
}
ADCPINX = 0x00; // change the index back to the default register.
ADCPD = 0x0001; // Lock the ADC calibration registers.}
}
Information Block Address Data [Word]
000016 unsigned int RevisionCode
000216 unsigned int count
007C16 Copy of SRID register indication for the
device revision number.
For PC87591E: FF0n16
For PC87591S: FF2n16
Software for Hardware Interface (Continued)
Revision 1.07 435 www.national.com
PC87591E/S/L
B.2 PROTECTION INFORMATION
The flash protection word is used to protect the contents of the on-chip flash from being altered. It also prevents the system
from executing from an erased flash and sets various system defaults. The following are examples of common settings for the
protection word. The protection word should be written into the flash as the last operation after updating the flash via the JTAG.
The protection word may be written by a write operation, using the programing tool to address 00FE16 in the information block
(block 2). Note that the protection word must be updated in all operating environments (DEV, OBD, PROG and IRE).
Example 1
Core boot block size is 4 Kbytes
Bit 3-0 (Core Boot Block): 1110
Shared BIOS using an expansion memory
Bit 4 (Host Boot Block): 1
Bit 6 (Force MBTA Zero): 0
RTC may be accessed by the host (at default)
Bit 5 (RTC Lock Default): 0
Flash is not protected to allow debug
Bits 9-7 (Flash Contents Protect): 111
Use RESET2 on pin IOPB7/RING/PFAIL/RESET2
Bits 15-14 (RST2EN): 01
The value that should be written to the protection word is 7F9E16 (binary 0111 1111 1001 1110).
Example 2
Same as Example 1, but for production version, once all debugging is completed. Change bits 9-7 from 111 to 000. Thus
the value that should be written to the protection word is 7C1E16 (binary 0111 1100 0001 1110).
Example 3
Core boot block size is 8 Kbytes
Bit 3-0 (Core Boot Block): 1101
Shared BIOS using an expansion memory
Bit 4 (Host Boot Block): 1
Bit 6 (Force MBTA Zero): 0
RTC may be accessed by the host (at default)
Bit 5 (RTC Lock Default): 0
Flash is not protected to allow debug
Bits 9-7 (Flash Contents Protect): 111
Use RESET2 on pin IOPD2/EXWINT24/RESET2
Bits 15-14 (RST2EN): 10
The value that should be written to the protection word is BF9D16 (binary 1011 1111 1001 1101).
Example 4
Core boot block size is 4 Kbytes
Bit 3-0 (Core Boot Block): 1110
Shared BIOS using an expansion memory
Bit 4 (Host Boot Block): 1
Bit 6 (Force MBTA Zero): 0
After reset, RTC may be accessed only by the core, and host access is blocked until host access is enabled by the
core.
Bit 5 (RTC Lock Default): 1
Flash is not protected to allow debug
Bits 9-7 (Flash Contents Protect): 111
Do not use RESET2 (only RESET1 is in use)
Bits 15-14 (RST2EN): 11
The value that should be written to the protection word is FFBE16 (binary 1111 1111 1011 1110)..
www.national.com 436 Revision1.07
PC87591E/S/L
Physical Dimensions inches (millimeters) unless otherwise noted
128-pin LQFP Package
Order Number: PC87591E-VLB/PC87591S-VLB
NS Package Number VLB128
PC87591E, PC87591S and PC87591L LPC Mobile Embedded Controllerswith SuperI/O Functions
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and whose
failure to perform, when properly used in accordance
with instructions for use provided in the labeling, can
be reasonably expected to result in a significant injury
to the user.
2. A critical component is any component of a life
support device or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
National Semiconductor
Corporation
Americas
Email:
new.feedback@nsc.com
National Semiconductor
Europe
Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 87 90
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
Email: ap.support@nsc.com
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
Email: nsj.crc@jksmtp.nsc.com
176-Low Profile Plastic Quad Flatpack (LQFP)
Order Number PC87591E-VPC/PC87591S-VPC/
PC87591L-VPC
NS Package Number VPC176
www.national.com