FXTH8709116T1 - NXP SEMICONDUCTORS

Freescale Semiconductor Document Number: FXTH870xD

Data Sheet: Advance Information Rev. 1.2, 09/2014

This document contains information on a new product. Specifications and information herein

are subject to change without notice.

An Energy-Efficient Solution by Freescale

FXTH870xD Tire Pressure Monitor

Sensor

The FXTH870xD family is comprised of the follow ing functions all within the

same package.

Features

• Pressure sensor with one of two calibrated pressure ranges

— 100 - 450 kPa

— 100 - 900 kPa

• Temperature sensor

• Optional XZ- or Z-axis accelerometer with adjustable offset option

• Voltage reference measured by ADC10

• Six-channel, 10-bit analog-to-d igital converter (ADC10) with two external

I/O inputs

• 8-bit MCU

— S08 Core with SIM and interrupt

— 512 RAM

— 8K FLASH (in addition to 8K providing factory firmware and trim

data)

— 64-byte, low-power, parameter registers

• Dedicated state machines to sequence routine measurement and

transmission processes for reduced power consumption

• Internal 315-/434-MHz RF transmitte r

— External crystal oscillator

— PLL-based output with fracti onal-n divider

— OOK and FSK modulation capability

— Programmable data rate generator

— Manchester, Bi-Phase or NRZ data encoding

— 256-bit RF data buffer variable length interrupt

— Direct access to RF transmitter from MCU for unique formats

— Low power consumption (less than 8 mA at 434 MHz, 5 dBM at

3.0 V, 25 °C)

• Differential input LF detector/decoder on independent signal pins

• Seven multipurpose GPIO pins

— Four pins can be connected to optional internal pullups/pulldowns and STOP4 wakeup interrupt

— Two of seven pins can be connected to a channel on the ADC10

— Two of seven pins can be connected to a channel on the TPM1

• Real-Time In terrupt driven by LFO with interrupt intervals of

8, 16, 32, 64, 128, 256, 512 or 1024 ms

• Low-power, wakeup timer and periodic reset driven by LFO

• Watch dog timeout with selectable times and clock sources

• Two-channel gene ral purpose timer/PWM module (TPM1)

FXTH870xD

Top and bottom view

Top view

Pin connections

24-Pin, 1-hole lid

7 x 7 QFN

Case 2264-03

18 PTA3

LFA

LFB

BKGD/PTA4

PTB1

PTA2

PTA1

RESET

VDD

VDDA

VSSA

VREG

PTB0

N/C

ID Feature

on top lid

PTA0

VSS

RFVSS

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 2

• Internal oscillators

— MCU bus clock of 0.5, 1, 2 and 4 MHz (1, 2, 4 and 8 MHz HFO)

— Low frequency, low power time clock (LFO) with 1 ms period

— Medium frequency, controller clock (MF O) of 8 sec period

• Low-voltage detection

• Normal temperature restart in hardware (over- or under-temperature detected by software)

ORDERING INFORMATION

Part number Accelerometer axis Package Range Code1

FXTH870502DT1 Z 2264 (7 x 7, 1-hole lid) 100-450 kPa $08

FXTH870511DT1 XZ 2264 (7 x 7, 1-hole lid) 100-450 kPa $0C

FXTH870902DT1 Z 2264 (7 x 7, 1-hole lid) 100-900 kPa $18

FXTH870911DT1 XZ 2264 (7 x 7, 1-hole lid) 100-900 kPa $1C

FXTH870912DT1 XZ Ext. Range 2264 (7 x 7, 1-hole lid) 100-900 kPa $1E

Related Documentation

The FXTH870xD device features and op erations are described in a variety of reference manuals, user guides, and application

notes. To find the most-current versions of these documents:

1. Go to the Freescale ho mepage at: http://www.freescale.com/

2. In the Keyword search box at the top of the page, enter the device number FXTH870xD.

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 1

Contents

1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.1 Overall Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2 Multi-Chip Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3 System Clock Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.4 Reference Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2 Pins and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1 Package Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Recommended Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.3 Signal Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.2 RUN Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.3 WAIT Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.4 ACTIVE BACKGROUND Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.5 STOP Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.1 MCU Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.2 Reset and Interrupt Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.3 MCU Register Addresses and Bit Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.4 High Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.5 MCU Parameter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.6 MCU RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.7 FLASH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.8 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.9 FLASH Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5 Reset, Interrupts and System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.2 MCU Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.3 Computer Operating Properly (COP) Wa tchdog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.4 SIM Test Register (SIMTST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.6 Low-Voltage Detect (LVD) System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.7 System Clock Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.8 Keyboard Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.9 Real Time Interrupt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

5.10 Temperature Sensor and Restart System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.11 Reset, Interrupt and System Control Registers And Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.12 System STOP Exit Status Register (SIMSES). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6 General Purpose I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.1 Unused Pin Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.2 Pin Behavior in STOP Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.3 General Purpose I/O Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.4 Port A Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.5 Port B Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

7 Keyboard Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.4 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.5 Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

7.6 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

8 Central Processing Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

8.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

8.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

8.3 Programmer’s Model and CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

8.4 Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

8.5 Special Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

8.6 HCS08 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

9 Timer Pulse-Width Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

FXTH870xD

Sensors

2Freescale Semiconductor, Inc.

9.2 TPM1 Configuration Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.3 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

9.4 Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

9.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

9.6 TPM1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

10 Other MCU Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

10.1 Pressure Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

10.2 Temperature Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

10.3 Voltage Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

10.4 Optional Acceleration Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

10.5 Optional Battery Condition Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

10.6 Measurement Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

10.7 Thermal Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

11 Periodic Wakeup Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

11.1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

11.2 Wakeup Divider Register - PWUDIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

11.3 PWU Control/Status Register 0 - PWUCS0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

11.4 PWU Control/Status Register 1 - PWUCS1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

11.5 PWU Wakeup Status Register - PWUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

11.6 Functional Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

12 LF Receiver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

12.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

12.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

12.3 Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

12.4 Input Amplifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

12.5 LFR Data Mode States. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

12.6 Carrier Detect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

12.7 Auto-Zero Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

12.8 Data Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

12.9 Data Clock Recovery and Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

12.10 Manchester Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

12.11 Duty-Cycle For Data Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

12.12 Input Signal Envelope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

12.13 Telegram Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

12.14 Error Detection and Handling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

12.15 Continuous ON Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

12.16 Initialization Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

12.17 LFR Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

13 RF Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

13.1 RF Data Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

13.2 RF Output Buffer Data Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

13.3 Transmission Randomization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

13.4 RFM in STOP1 Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

13.5 Data Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

13.6 RF Output Stage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

13.7 RF Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

13.8 Datagram Transmission Times. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

13.9 RFM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

13.10 RFM Control Register 1 - RFCR1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

13.11 RFM Control Register 2 - RFCR2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

13.12 RFM Control Register 3 - RFCR3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

13.13 RFM Control Register 4 - RFCR4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

13.14 RFM Control Register 5 - RFCR5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

13.15 RFM Control Register 6 - RFCR6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

13.16 RFM Control Register 7 - RFCR7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

13.17 PLL Control Registers A- PLLCR[1:0], RPAGE = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

13.18 PLL Control Registers B- PLLCR[3:2], RPAGE = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

13.19 EPR Register - EPR (RPAGE = 1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

13.20 RF DATA Registers - RFD[31:0] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

13.21 VCO Calibration Machine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

14 Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

14.1 Software Jump Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

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14.2 Function Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

14.3 Memory Resource Usage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

15 Development Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

15.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

15.2 Background Debug Controller (BDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

15.3 Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

16 Battery Charge Consumption Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

16.1 Standby Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

16.2 Measurement Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

16.3 Transmission Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

16.4 Total Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

17 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

17.1 Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

17.2 Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

17.3 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

17.4 Power Consumption (MCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

17.5 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

17.6 Voltage Measurement Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

17.7 Temperature Measurement Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

17.8 Pressure Measurement Characteristic (100 to 450 kPa ranges) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

17.9 Pressure Measurement Characteristic (100 to 900 kPa Ranges) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

17.10 Optional Acceleration Sensor Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

17.11 LFR Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

17.12 LFR Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

17.13 LFR Power Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

17.14 RF Output Stage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

17.15 Power Consumption RF Transmissions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

18 Mechanical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

18.1 Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

18.2 Media Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

18.3 Mounting Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

19 Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

20 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

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1 General Information

1.1 Overall Block Diagram

The block diagram of the FXTH870xD is shown in Figure 1. This diagram covers all the main blocks mentioned above and their

main signal interactions. Power management controls and bus control signals are no t shown in this block diagram for clarity.

1.2 Multi-Chip Interface

The FXTH870xD contains two to three devices using the best process technology for each.

• Microcontroller with accelerometer and pressure sensor interfaces, and RF transmitter (MCU)

• Optional ranges on pressure transducers

• Optional XZ- or Z-axis acceleration transducer

As shown in Figure 1 the MCU interfaces to the RF transmitter using a standard memory mapped registers. The transducers

connect to the MCU using custom analog interfaces and inter-chip bonding wires.

1.3 System Clock Distribution

The various clock sources and their distribution are shown in Figure 2. All clock sources except the low frequency oscillator , LFO,

can be turned off by software control in order to conserve power.

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Freescale Semiconductor, Inc. 5

Figure 1. FXTH870xD Overall Block Diagram

8K USER

FLASH

MEMORY

RAM

MEMORY

512

TPM1

TIMER/PWM

2-CHAN

LVD

RTI

TIMER

MCU CORE

S08

AVDD

TEMP AVDD

AVSS

TEMP

SENSOR

PRESS

SENSOR

BANDGAP

REF

LFA

PTA1

ADC10

10-BIT

6-CHAN

TEMP

BKGD

LFB

64 Byte

PARAMETER

DATA

ENCODE

BIT

RATE

256-BIT

DATA

BUFFER

AMP

VCO/PLL

FRACTL

DIVIDER

XTAL

OSC

MCU

TRANSDUCERS

VOLT

REG

RESTART

OSC

GEN

PWU

TIMER

MFO

8 Sec

RESET

RECVR

SENS

LFO

1 ms

LFI

SMI

HFO

1, 2, 4 or 8

MHz

I/O

KEY

KBI

BOARD

WAKEUP

MFO

FIRMWARE

MEMORY

PTA0

SENSOR MEASUREMENT

(SMI)

RF CONTROLLER

INTERFACE

LFO

(LFR)

RFM

VREG

PTA2

VDD

VSS

RVSS

PTA3

RF LVD

AVDD

RFVDD

VREG

PTB0

PTB1

PTA4

ACCEL

(OPTION)

ACCEL

(OPTION)

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6Freescale Semiconductor, Inc.

Figure 2. FXTH870xD Clock Distribution

1.4 Reference Documents

The FXTH870xD utilizes the standard product MC9S08 CPU core. The user can obtain further detail on the full capabilities of

this core by referring to the HCS08 Family Reference Manual (HCS08RMV1).

RTI

SYSTEM

CONTROL

LOGIC

 2

HFO OSC

1, 2, 4, fOSC fBUS

CPU

BDC

TPM1

RAM FLASH

LFR

ADC10

MFO

OSC

8 Sec

PWU

CLSA, CLKSB

fLFO (1 kHz)

XTL

OSC

26 MHz

XI XO PLL VCO

BIT

RATE

DATA

BUFFER

PRESSURE

SENSOR

TRANSDUCERS

MCU

RTICLKS

PAR

REG

fMFO

fXCO

GEN

DX (500 kHz)

LFO

OSC

1 mS

PERIOD

SENSOR MEASUREMENT

INTERFACE

ADC10

CLOCK

ADCCLK ADC10

BUSCLKS[1:0]

WATCH

DOG

COPCLKS

Z-AXIS

SENSOR

4 kbps

(125 kHz)

RF STAT E

MACHINE

LFRO

OSCILL

 8

TCLKDIV

LFOSEL

fMFO

PTA3

PTA2

fLFO (1 kHz)

CH0 CH1

RANDOM

(0 - 1 MHz)

RANDOM

(0 - 1 MHz)

OUT 41.67 kHz

Sampling 41.67 kHz

Sampling

and 8 MHz

X-AXIS

SENSOR

41.67 kHz

Sampling

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Freescale Semiconductor, Inc. 7

2 Pins and Connections

This section describes the pin layout and general function of each pin.

2.1 Package Pinout

The pinout for the FXTH870xD device QFN package is shown in Figure 3 for the orientation of the pressure port up. The

orientation of the internal Z-axis accelerometer is shown in Figure 4.

Figure 3. FXTH870xD QFN Package Pinout

Figure 4. FXTH870xD QFN Optional Z-axis Accelerometer Orientation

2.2 Recommended Application

Example of a simple OOK/FSK tire pressure monitors using the internal PLL-based RF output stage is shown in Figure 5. Any of

the PTA[3:0] pins can also be used as general purpose I/O pins. Any of the PTA[3:0] pins that are not used in the application

should be handled as described in Section 6.1.

18 PTA3

LFA

LFB

BKGD/PTA4

PTB1

PTA2

PTA1

RESET

VDD

VDDA

VSSA

VREG

PTB0

N/C

ID Feature

on top lid

PTA0

VSS

RFVSS

N/C = No Connect: Do not connect PCB pads to signal traces, power/ground or multi-layer via.

Top View

BKGD/PTA4

X-AXIS

ORIENTATION

-X

Y-AXIS

ORIENTATION

-Y

Side View

Pressure

Port

POSITIVE ACCELERATION MOVES MASS

IN +Z DIRECTION (VALUE INCREASES)

Z-AXIS

ORIENTATION

-Z

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8Freescale Semiconductor, Inc.

2.3 Signal Properties

The following sections describe the general function of each pin.

Figure 5. FXTH870xD Example Application

2.3.1 VDD and VSS Pins

The digital circuits operate from a single power supply connected to the FXTH870xD through the VDD and VSS pins. VDD is the

positive supply and VSS is the ground. The conductors to the power supply should be connected to the VDD and VSS pins and

locally decoupled as shown in Figure 6.

Care should be taken to reduce measurement signal noise by separating the VDD, VSS, A VDD, AVSS and RVSS pins using a “star”

connection such that each metal trace does not share any load currents with other external devices as shown in Figure 6.

2.3.2 AVDD and AVSS Pins

The analog circuits operate from a single power supply connected to the FXTH870xD through the AVDD and AVSS pins. AVDD is

the positive supply and A VSS is the ground. The conductors to the power supply should be connected to the A VDD and A VSS pins

and locally decoupled as shown in Figure 6.

FXTH870xxx

0.1 µF

VDD

VSS

3.0 V

BATTERY

COIL

XTAL

RVSS

ANT

BKGD/PTA4

LFA

LFB

PTA1

RESET

GENERAL

PURPOSE I/O

PTA0

PTA2

AVDD

AVSS

VREG

470 nF

0.1 µF

PTA3

MATCHING

NETWORK

C2 C3

C2, C3, C4

optimized

for crystal

C4*

R2 R3

R2 and R3, <10 k

recommended for

highest EMC resistance

PTB0

PTB1

L1 and matching network

optimized for specific PWB and

antenna layout. Recommend

0603 minimum size for L1 and

other matching network inductors

for maximum efficiency.

C1 and R1 optimized

for coil used, but

recommended

RC < 15.3 sec.

The device C4, although drawn her e as a capacitor, may be any type of passive compo nen t(s) sufficient to block

or reduce unwanted external radiated signals from corrupting the crystal oscillator circuit: PCB traces for the LF A

/ LFB, AVDD / VDD, and VSS / AVSS pins and byp ass capacitors should be minimized to reduce unw anted external

radiated signals from corrupting the power input circuits.

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Freescale Semiconductor, Inc. 9

Care should be taken to reduce measurement signal noise by separating the VDD, VSS, A VDD, AVSS and RVSS pins using a “star”

connection such that each metal trace does not share any load currents with other external devices as shown in Figure 6.

Figure 6. Recommended Power Supply Connections

2.3.3 VREG Pin

The internal regulator for the analog circuits requires an external stabilization capacitor to AV SS.

2.3.4 RVSS Pin

Power in the RF output amplifier is returned to the supply through the RVSS pin. This conductor should be connected to the power

supply as shown in Figure 6 using a “star” connection such that each metal trace does not share any load currents with other

supply pins.

2.3.5 RF Pin

The RF pin is the RF energy data supplied by the FXTH870xD to an exte rnal antenna.

2.3.6 XO, XI Pins

The XO and XI pins are for an external crystal to be used by the internal PLL for creating the carrier frequencies and data rates

for the RF pin.

2.3.7 LF[A:B] Pins

The LF[A:B] pins can be used by the LF receiver (LFR) as one di fferential input channel fo r sensing low level signals from an

external low frequency (LF) coil. The external LF coil should be connected between the LFA and the LFB pins.

Signaling into the LFR pins can place the FXTH870xD into various diagnostic or operational modes. The LFR is comprised of

the detector and the decoder.

Each LF[A:B] pin will always have an impedance of ap proximately 500 k to VSS due to the LFR input circuitry. The LFA/LFB

pins are used by the LFR when the LFEN control bit is set and are not functional when the LFEN control bit is clear.

2.3.8 PTA[1:0] Pins

The PTA[1:0] pins are general purpose I/O pins. These two pins can be configured as normal bidirectional I/O pins with

programmable pullup or pulldown devices and/or wakeup interrupt capability; or one or both can be connected to the two input

channels of the A/D converter module. The pulldown devices can only be activated if the wakeup interrupt capability is enabled.

User software must configure the general purpose I/O pins so that they do not result in “floating” inputs as described in

Section 6.1. PTA[1:0] map to Keyboard Interrupt function bits [1:0].

0.1 µF

FXTH870xxx

VDD

VSS

to other

Battery

IDD ILOAD

Bypass capacitors

closely coupled to

the package pins

FXTH870xxx and Other Load Currents

star connected to battery terminals

loads

0.1 µF

AVDD

AVSS

RVSS

The decoupling devices, although

drawn here as 0.1 F capacitors,

may be any type of passive component(s)

sufficient to block or reduce unwanted

external radiated signals from corrupting

the power input protection circuits;

application tuning may be required.

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10 Freescale Semiconductor, Inc.

2.3.9 PTA[3:2] Pins

The PTA[3:2] pins are general purpose I/O pin. These two pins can be configu red as normal bidirectional I/O pin with

programmable pullup or pulldown devices and/or wakeup interrupt capability; or one or both can be connected to the two input

channels of the Timer Pulse Width (TPM1) module. The pulldown devices can only be activated if the wakeup interrupt capability

is enabled. User software must configure the general purpose I/O pins so that they do not result in “floating” inputs as described

in Section 6.1. PTA[3:2] map to Keyboard Interrupt function bit s [3:2].

2.3.10 BKGD/PTA4 Pin

The BKGD/PTA4 pin is used to place the FXTH870xD in the BACKGROUND DEBUG mode (BDM) to evaluate MCU code and

to also transfer data to/from the internal memories. If the BKGD/PTA4 pin is held low when the FXTH870xD comes out of a power-

on reset the device will go into the ACTIVE BACKGROUND DEBUG mode (BDM).

The BKGD/PTA4 pin has an internal pullup device and can connected to VDD in the application unless there is a need to enter

BDM operation after the device as been soldered into the PWB. If in-circuit BDM is desired the BKGD/PTA4 pin can be left

unconnected, but should be connecte d to VDD through a low impedance resistor (<10 k) which can be ove r-d ri ve n by an

external signal. This low impedance resistor reduces the possibility of getting into the debug mode in the application due to an

EMC event.

2.3.11 RESET Pin

The RESET pin is used for test and establishing the BDM condition and providing the programming voltage source to the internal

FLASH memory. This pin can also be used to direct to the MCU to the reset vector as described in Section 5.2.

The RESET pin has an internal pullup device and can connected to VDD in the application unless there is a need to enter BDM

operation after the device as been soldered to the PWB. If in-circuit BDM is desired the RESET pin can be left unconnected; but

should be connected to VDD through a low impedance resistor (<10 k) which can be over-driven by an external signal. This low

impedance resistor reduces the possibility of getting into the debug mode in the application due to an EMC event.

Activation of the external reset function occurs when the voltage on the RESET pin goes below 0.3 x VDD for at least 100 nsec

before rising above 0.7 x VDD as shown in Figure 7.

Figure 7. RESET Pin Timing

2.3.12 PTB[1:0] Pins

The PTB[1:0] pins are general purpose I/O pins. These two pins can be configured as nominal bidirectional I/O pins with

programmable pullup devices. User software must configure the general purpose I/O pins so that they do not result in “floating”

inputs as described in Section 6.1

RESET 0.7 VDD

0.3 VDD

> 100 nsec

Reset

Initiated

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Freescale Semiconductor, Inc. 11

3 Modes of Operation

The operating modes of the FXTH870xD are described in this section. Entry into each mode, exit from each mode, and

functionality while in each of the modes are described.

3.1 Features

• ACTIVE BACKGROUND DEBUG mode for code development

• STOP modes:

— System clocks stopped

— STOP1: Power down of most internal circuits, including RAM, for maximum power savings; voltage regulator in

standby

— STOP4: All internal circuits powered and full voltage regulation maintained for fastest recovery

3.2 RUN Mode

This is the normal operating mode for the FXTH870xD. This mode is selected when the BKGD/PT A4 pin is high at the rising edge

of reset. In this mode, the CPU executes code from internal memory following a reset with execution beginning at address

specified by the reset pseudo-vector ($DFFE and $DFFF).

3.3 WAIT Mode

The WAIT mode is also present like other members of the Freescale S08 family members; but is not normally used by the

FXTH870xD firmware or typical TPMS applications.

3.4 ACTIVE BACKGROUND Mode

The ACTIVE BACKGROUND mode functions are managed through the BACKGROUND DEBUG controller (BDC) in the HCS08

core. The BDC provides the means for analyzing MCU operation during software development.

ACTIVE BACKGROUND mode is entered in any of four ways:

• When the BKGD/PTA4 pin is low at the rising edge of a power up reset

• When a BACKGROUND command is received through the BKGD/PTA4 pin

• When a BGND instruction is executed by the CPU

• When encountering a BDC breakpoint

Once in ACTIVE BACKGROUND mode, the CPU is held in a suspended state waiting for serial BACKGROUND commands

rather than executing instructions fro m the user’s application program. Background commands are of two types:

• Non-intrusive commands, define d as commands that can be issued while the user program is running. Non-in trusive

commands can be issued through the BKGD/PTA4 pin while the MCU is in RUN mode; non-intrusive commands can also

be executed when the MCU is in the ACTIVE BACKGROUND mode. Non-intrusive commands include:

— Memory access commands

— Memory-access-with-status commands

— BDC register access commands

— The BACKGROUND command

• ACTIVE BACKGROUND commands, which can only be executed while the MCU is in ACTIVE BACKGROUND mode.

ACTIVE BACKGROUND commands include commands to:

— Read or write CPU registers

— Trace one user program instruct io n at a ti me

— Leave ACTIVE BACKGROUND mode to return to the user’s application program (GO)

The ACTIVE BACKGROUND mode is used to program a bootloade r or user application program into the FLASH program

memory before the MCU is operated in RUN mode for the first time. When the FXTH870xD is shipped from the Freescale factory ,

the FLASH program memory is erased by default (unless specifically requested otherwise) so there is no program that could be

executed in RUN mode until the FLASH memory is initially programmed.

The ACTIVE BACKGROUND mode can also be used to erase and reprogram the FLASH memory after it has been previously

programmed.

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12 Freescale Semiconductor, Inc.

3.5 STOP Modes

One of two stop modes are entered upon execution of a STOP instruction when the STOPE bit in the system option register is

set. In all STOP modes, all internal clocks are halted except for the low frequency 1 kHz oscillator (LFO) which runs continuously

whenever power is applied to the VDD and VSS pins. If the STOPE bit is not set when the CPU executes a STOP instruction, the

MCU will not enter any of the STOP modes and an illegal opcode reset is forced. The STOP modes are selected by setting the

appropriate bits in SPMSC2. Table 1 summarizes the behavior of the MCU in each of the STOP1 and STOP4 modes. The STOP2

mode found in other Freescale S08 family members is not available; but the STOP3 mode is present like other members of the

Freescale S08 family members.

3.5.1 STOP1 Mode

The STOP1 mode provides the lowest possible standby power consumption by causing the internal circuitry of the MCU to be

powered down.

When the MCU is in STOP1 mode, all internal circuits that are powered from the voltage regulator are turned off. The voltage

regulator is in a low-power standby state. STOP1 is exited by asserting either a reset or an interrupt function to the MCU.

Entering STOP1 mode automatically asserts LVD. STOP1 cannot be exited until the VDD is greater than VLVDH or VLV/DL rising

(VDD must rise above the LVI re-arm voltage).

Upon wakeup from STOP1 mode, the MCU will start up as from a power-on reset (POR) by taking the reset vector.

NOTE

If there are any pending interrupts that have yet to be serviced then the device will not go

into the STOP1 mode. Be certain that all interrupt flags have been cleared before entry to

STOP1 mode.

3.5.2 STOP4 LVD Enabled in STOP Mode

The LVD system is capable of generating either an interrupt or a reset when the supply voltage drops below the LVD voltage. If

the LVD is enab led by setting the LV DE and the LVDSE bits in SPMSC1 when the CPU executes a STOP instruction, then the

voltage regulator remains active during STOP mode. If the user attempts to enter the STOP1 with the LVD enabled in STOP

(LVDSE = 1), the MCU will enter STOP4 instead.

Table 1. STOP Mode Behavior

Mode STOP1 STOP4

LFO Oscillator, PWU Always On & Clocking

Real-Time Interrupt (RTI)(1) Always On if using LFO as Clock

MFO Oscillator(2) Optionally On Optionally On

HFO Oscillator Off Off

CPU Off Standby

RAM Off Standby

Parameter Registers On On

FLASH Off Standby

TPM1 2-Chan Timer/PWM Off Off

Digital I/O Disabled Standby

Sensor Measurement Interface (SMI) Off Optionally On

Pressure P-cell Off Optionally On

Optional Acceleration g-cell Off Optionally On

Temperature Sensor (in ADC10) Off Optionally On(3)

Normal Temperature Restart Optionally On Optionally On

Voltage Reference (in ADC10) Off Optionally On(3)

LFR Detector(4) Periodically On Periodically On

LFR Decoder Optionally On Optionally On

RF Controller, Data Buffer, Encoder Optionally On Optionally On

RF Transmitter(5) Optionally On Optionally On

ADC10 Off Optionally On(3)

FXTH870xD

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S pecific to the tire pressure monitoring application the parameter registers and the LFO with wakeup timer are powered up at all

times whenever voltage is applied to the supply pins. The LFR detector and MFO may be periodically powered up by the LFR

decoder.

3.5.3 Active BDM Enabled in STOP Mode

Entry into the ACTIVE BACKGROUND DEBUG mode from RUN mode is enabled if the ENBDM bit in BDCSCR is set. The

BDCSCR register is not memory mapped so it can only be accessed through the BDM interface by use of the BDM commands

READ_STA TUS and WRITE _CONTROL. If ENBDM is set when the CPU executes a STOP instruction, the system clocks to the

BACKGROUND DEBUG logic remain active when the MCU enters STOP mode so BACKGROUND DEBUG communication is

still possible. In addition, the voltage regulator does not enter its low-power standby state but maintains full internal regulation. If

the user attempts to enter the STOP1 with ENDBM set, the MCU will instead enter this mode which is STOP4 with system clocks

running.

Most BACKGROUND commands are not available in STOP mode. The memory-access-with-status commands do not al l o w

memory access, but they report an error indicating that the MCU is in STOP mode. The BACKGROUND command can be used

to wake the MCU from stop and enter ACTIVE BACKGROUND mode if the ENDBM bit is set. Once in BACKGROUND DEBUG

mode, all BACKGROUND commands are available.

3.5.4 MCU On-Chip Peripheral Modules in STOP Modes

When the MCU enters any STOP mode, system clocks to the internal peripheral modules except the wakeup timer and LFR

detectors/decoder are stopped. Even in the exception case (ENDBM = 1), where clocks are kept alive to the BACKGROUND

debug logic, clocks to the peripheral systems are halted to reduce power consumption.

I/O Pins

If the MCU is configured to go into STOP1 mode, the I/O pins are forced to their default reset state (Hi-Z) upon entry into stop.

This means that the I/O input and output buffers are turned off and the pullup is disconnected.

Memory

All module interface registers will be reset upon wakeup from STOP1 and the contents of RAM are not preserved. The MCU must

be initialized as upon reset. The contents of the FLASH memory are non-volatile and are preserved in any of the STOP modes.

Parameter Registers

The 64 bytes of parameter registers are kept active in all modes of operation as long as power is applied to the supply pins. The

contents of the parameter registers behave like RAM and are unaffected by any reset.

LFO

The LFO remains active regard less of any mode of operation.

MFO

The medium frequency oscillator (MFO) will remain powered up when the MCU enters the STOP mode only when the SMI has

been initiated to make a pressure or acceleration measurement; or when the RF transmitter’s state machine is processing data.

HFO

The HFO is halted in all STOP modes.

PWU

The PWU remains active regardless of any mode of operation.

Regulator Off On

I/O Pins Hi-Z States Held

Wakeup Methods Interrupts, resets Interrupts, resets

1. RTI can be used in STOP1 or STOP4 if the clock selected is the LFO. To use the HFO as the clock the MCU must be in the RUN mode.

2. MFO oscillator started if the LFR detectors are periodically sampled, the LFR det ectors detect an input signal; a pressure or acceleration

reading is in progress or the RF state machine is sending data.

3. Requires internal ADC10 clock to be enabled.

4. Period of sampling set by MCU.

5. RF data buffer may be set up to run while the CPU is in the STOP modes.

Table 1. STOP Mode B ehavior (continued )

Mode STOP1 STOP4

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14 Freescale Semiconductor, Inc.

ADC10

The internal asynchronous ADC10 clock is always used as the conversion clock. The ADC10 can continue operation during

STOP4 mode. Conversions can be initiated while the MCU is the STOP4 mode. All ADC10 module registers contain their reset

values following exit from STOP1 mode.

LFR

When the MCU enters STOP mode the detectors in the LFR will remain powered up depending on the states of the bits selecting

the periodic sampling. Refer to Section 12 for more details.

Bandgap Reference

The bandgap reference is enabled whe never the sensor measurement interface requires sensor or voltage measurements.

TPM1

When the MCU enters STOP mode, the clock to the TPM1 module stops and the module halts operation. If the MCU is configured

to go into STOP1 mode, the TPM1 module will be reset upon wakeup from STOP and must be re-initialized.

Voltage Regulator

The voltage regulator enters a low-power standby state when the MCU enters any of the STOP modes except STOP4 (LVDSE

= 1 or ENBDM =1).

Temperature Sensor

The temperature sensor is powered up on command from the MCU.

Temperature Re start

When the MCU enters a STOP mode the temperature restart will remain powered up if the TRE bit is set. If the temperature restart

level is reached the MCU will restart from the reset vector.

3.5.5 RFM Module in STOP Modes

The RFM’s external crystal oscillator (XCO), bit rate generator , PLL, VCO, RF data buffer , dat a encoder, and RF output stage will

remain powered up in STOP modes during a transmission, or if the SEND bit has been set and DIRECT mode has been enabled.

RF Output

When the RFM finishes a transmission sequence the external crystal oscillator (XCO), bit rate generator, PLL, VCO, RF data

buffer, data encoder, and RF output stage will remain powered up if the SEND bit is set.

3.5.6 P-cell in STOP Modes

The P-cell is powered up only during a measurement if scheduled by the sensor measurement interface. Otherwise it is powered

down.

3.5.7 Optional g-Cell in STOP Modes

The g-cell is powered up only during a measurement if scheduled by the sensor measurement interface. Otherwise it is powered

down.

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Freescale Semiconductor, Inc. 15

4Memory

The overall memory map of the FXTH870xD resides on the MCU.

4.1 MCU Memory Map

As shown in Figure 8, MCU on-chip memory in the FXTH870xD consists of parameter registers, RAM, FLASH program memory

for nonvolatile data storage, and I/O and control/status registers. The registers are divided into four groups:

• Direct-page registers ($0000 through $004F)

• Parameter registers ($0050 through $008F)

• RAM ($0090 through $028F)

• High-page registers ($1800 through $182B)

Figure 8. FXTH870xD MCU Memory Map

The total programmable FLASH memory map is 16K, but the upper 8K is used for firmware and test software. Upon power up

the firmware will initialize the device and redirect all vectors to the user area from $DFC0 through $DFFF . Any calls to the firmware

subroutines are accessed through a jump table starting at location $E000 (see Section 14).

4.2 Reset and Interrupt Vectors

Table 2 shows address assignments for jump table to the reset and interrupt vectors. The vector names shown in this table are

the labels used in the equate file provided by Freescale in the CodeWarrior project file.

Table 2. Vector Summary

User Vector Addr Vector Name Module Source

$DFE0:DFE1 Vkbi KBI

$DFE2:DFE3 Reserved

$DFE4:DFE5 Reserved

$DFE6:DFE7 Vrti Sys Ctrl - RTI

$DFE8:DFE9 Vlfrcvr LFR

$DFEA:DFEB Vadc1 ADC10

$DFEC:DFED Vrf RFM

$0000

$004F

$0050

$008F

$1800

$17FF

$182B

$182C

$FFFF

$0090

$C000

$BFFF

DIRECT PAGE REGISTERS

RAM 512 BYTES

UNIMPLEMENTED

HIGH PAGE REGISTERS

5488 BYTES

41964 BYTES

$028F

$0290

PARAMETER REGISTERS

$DFC0

$DFBF

USER FLASH

8128 BYTES

USER VECTORS

FIRMWARE FLASH

8128 BYTES

$E000

$DFFF

$E040

$E03F

FIRMWARE JUMP TABLE

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4.3 MCU Register Addresses and Bit Assignments

The registers in the FXTH870 xD are divided into these four groups:

• Direct-page registers are located in the first 80 locations in the memory map; these are accessible with efficient direct

addressing mode instructions.

• The parameter registers begin at address $0050; these are also accessible with efficient direct addressing mode

instructions.

• High-page registers are used less often, so they are located above $1800 in the memory map. This leaves more room in the

direct page for more frequently used registers and variables.

• The nonvolatile register area consists of a block of 16 locations in FLASH memory at $FFB0:FFBF. Nonvolatile register

locations include:

— Three values that are loaded into working registers at reset

— An 8-byte back door comparison key that optionally allows the user to gain controlled access to secure memory.

Because the nonvolatile register locations are FLASH memory , they must be erased and programmed like other FLASH memory

locations.

Direct page registers are located within the first 256 locations in the memory map, so they are accessible with efficient direct

addressing mode instructions, which requires only the lower byte of the address. Bit manipulation instructions can be used to

access any bit in any direct-page register. Table 3 is a summary of all user-accessible direct-page registers and control bits.

Those related to the TPMS application and modul es are described in detail in this specification.

The register names in column two of the following tables are shown in bold to set them apart from the bit names to the right. Cells

that are not associated with named bits are shaded. A shaded cell with a 0 indicates this unused bit always reads as a 0. Shaded

cells with dashes indicate unused or reserve d bit locations that could read as 1s or 0s.

$DFEE:DFEF Vsm SMI

$DFF0:DFF1 Vtpm1ovf TPM1

$DFF2:DFF3 Vtpm1ch1 TPM1

$DFF4:DFF5 Vtpm1ch0 TPM1

$DFF6:DFF7 Vwuktmr PWU

$DFF8:DFF9 Vlvd Sys Ctrl - LVD

$DFFA:DFFB Reserved

$DFFC:DFFD Vswi SWI opcode

$DFFE:DFFF Vreset Sys Ctrl - POR, PRF, COP, LVD

Temp Restart, Illegal opcode or address

Table 3. MCU Direct Page Register Summary

AddressRegister NameBit 7654321Bit 0

$0000 PTAD PTAD[4:0]

$0001 PTAPE PTAPE[3:0]

$0002 Reserved

$0003 PTADD PTADD[3:0]

$0004 PTBD PTBD[1:0]

$0005 PTBPE PTBPE[1:0]

$0006 Reserved

$0007 PTBDD PTBDD[1:0]

$0008 Reserved

$0009 Reserved

$000A Reserved

$000B Reserved

$000C KBISC 0000 KBF KBACK KBIE KBIMOD

Table 2. Vector Summary (continued)

User Vector Addr Vector Name Module Source

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$000D KBIPE KBIPE[3:0]

$000E KBIES KBEDG[3:0]

$000F Reserved

$0010 TPM1SC TOF TOIE CPWMS CLKSB CLKSA PS2 PS1 PS0

$0011 TPM1CNTH Bit [15:8]

$0012 TPM1CNTL Bit [7:0]

$0013 TPM1MODH Bit [15:8]

$0014 TPM1MODL Bit [7:0]

$0015 TPM1C0SC CH0F CH0IE MS0B MS0A ELS0B ELS0A 0 0

$0016 TPM1C0VH Bit [15:8]

$0017 TPM1C0VL Bit [7:0]

$0018 TPM1C1SC CH1F CH1IE MS1B MS1A ELS1B ELS1A 0 0

$0019 TPM1C1VH Bit [15:8]

$001A TPM1C1VL Bit [7:0]

$001B Reserved

$001C PWUDIV WDIV[5:0]

$001D PWUCS0 WUF WUFAK WUT[5:0]

$001E PWUCS1 PRF PRFAK PRST[5:0]

$001F PWUS PSEL 0 CSTAT[5:0]

$0020-27 LFR Registers LFR Registers, see Table 4 and Table 5

$0028 ADSC1 COCO AIEN ADCO ADCH[4:0]

$0029 ADSC2 ADACT ADTRG ACFE ADCFGT 0 0 0 0

$002A ADRH 0000 ADR[11:8]

$002B ADRL ADR[7:0]

$002C ADCVH 0000 ADCV[11:8]

$002D ADCVL ADCV[7:0]

$002E ADCFG ADLPC ADIV[1:0] ADLSMP MODE[1:0] ADICLK[1:0]

$002F ADPCTL1 ADPC[7:0]

$0030-4F RFM Registers RFM Registers, see Table 6 and Table 7

$0050-8F Parameter Reg PARAM[63:0]

Note: Shaded bits are recommended to only be controlled by firmware or factory test.

Table 4. LFR Register Summary - LPAGE = 0

AddressRegister NameBit 7654321Bit 0

$0020 LFCTL1 LFEN SRES CARMOD LPAGE IDSEL[1:0] SENS[1:0]

$0021 LFCTL2 LFSTM[3:0] LFONTM[3:0]

$0022 LFCTL3 LFDO TOGMOD SYNC[1:0] LFCDTM[3:0]

$0023 LFCTL4 LFDRIE LFERIE LFCDIE LFIDIE DECEN VALEN TIMOUT[1:0]

$0024 LFS LFDRF LFERF LFCDF LFIDF LFOVF LFEOMF LPSM LFIAK

$0025 LFDATA RXDATA[7:0]

$0026 LFIDL ID[7:0]

$0027 LFIDH ID[15:8]

Table 3. MCU Direct Page Register Summary (continued)

AddressRegister NameBit 7654321Bit 0

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Table 5. LFR Register Summary - LPAGE = 1

AddressRegister NameBit 7654321Bit 0

$0020 LFCTL1 LFEN SRES CARMOD LPAGE IDSEL[1:0] SENS[1:0]

$0021 LFCTRLE TRIMEE AZSC[2:0]

$0022 LFCTRLD AVFOF[1:0} DEQS AZDC[1:0] ONMODE CHK125[1:0]

$0023 LFCTRLC AMPGAIN[1:0] FINSEL[1:0] AZEN LOWQ[1:0] DEQEN

$0024 LFCTRLB HYST[1:0] LFFAF LFCAF LFPOL LFCPTAZ[2:0]

$0025 LFCTRLA TESTSEL[3:0] LFCC[3:0]

$0026 Reserved

$0027 Reserved

Note: Shaded bits are recommended to only be controlled by firmware or factory test.

Table 6. RFM Register Summary - RPAGE = 0

AddressRegister NameBit 7654321Bit 0

$0030 RFCR0 BPS[7:0]

$0031 RFCR1 FRM[7:0]

$0032 RFCR2 SEND RPAGE EOM PWR[4:0]

$0033 RFCR3 DATA IFPD ISPC IFID FNUM[3:0]

$0034 RFCR4 RFBT[7:0]

$0035 RFCR5 BOOST LFSR[6:0]

$0036 RFCR6 VCO_GAIN[1:0] RFFT[5:0]

$0037 RFCR7 RFIF RFEF RFVF RFIAK RFIEN RFLVDEN RCTS RFMRST

$0038 PLLCR0 AFREQ[12:5]

$0039 PLLCR1 AFREQ[4:0] POL CODE[1:0]

$003A PLLCR2 BFREQ[12:5]

$003B PLLCR3 BFREQ[4:0] CF MOD CKREF

$003C RFD0 RFD[7:0]

$003D RFD1 RFD[15:8]

$003E RFD2 RFD[23:16]

$003F RFD3 RFD[31:24]

$0040 RFD4 RFD[39:32]

$0041 RFD5 RFD[47:40]

$0042 RFD6 RFD[55:48]

$0043 RFD7 RFD[63:56]

$0044 RFD8 RFD[71:64]]

$0045 RFD9 RFD[79:72]

$0046 RFD10 RFD[87:80]

$0047 RFD11 RFD[95:88]

$0048 RFD12 RFD[103:96]

$0049 RFD13 RFD[111:104]

$004A RFD14 RFD[119:112]

$004B RFD15 RFD[127:120]

$004C Reserved

$004D Reserved

$004E Reserved

$004F Reserved

Note: Shaded bits are recommended to only be controlled by firmware or factory test.

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Table 7. RFM Register Summary - RPAGE = 1

AddressRegister NameBit 7654321Bit 0

$0030 RFCR0 BPS[7:0]

$0031 RFCR1 FRM[7:0]

$0032 RFCR2 SEND RPAGE EOM PWR[4:0]

$0033 RFCR3 DATA IFPD ISPC IFID FNUM[3:0]

$0034 RFCR4 RFBT[7:0]

$0035 RFCR5 BOOST LFSR[6:0]

$0036 RFCR6 VCO_GAIN[1:0] RFFT[5:0]

$0037 RFCR7 RFIF RFEF RFVF RFIAK RFIEN RFLVDEN RCTS RFMRST

$0038 EPR —/VCD3 PLL_LPF_[2:0]/VCD[2:0] PA_SLOPE VCD_EN

$0039 Reserved

$003A Reserved

$003B Reserved

$003C RFD0 RFD[135:128]

$003D RFD1 RFD[143:136]

$003E RFD2 RFD[151:144]

$003F RFD3 RFD[159:152]

$0040 RFD4 RFD[167:160]

$0041 RFD5 RFD[175:168]

$0042 RFD6 RFD[183:176]

$0043 RFD7 RFD[191:184]

$0044 RFD8 RFD[199:192]

$0045 RFD9 RFD[207:200]

$0046 RFD10 RFD[215:208]

$0047 RFD11 RFD[223:216]

$0048 RFD12 RFD[231:224]

$0049 RFD13 RFD[239:232]

$004A RFD14 RFD[247:240]

$004B RFD15 RFD[255:248]

$004C Reserved

$004D Reserved

$004E Reserved

$004F Reserved

Note: Shaded bits are recommended to only be controlled by firmware or factory test.

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4.4 High Address Registers

High-page registers are used much less often, so they are located above $1800 in the memory map. This leaves more room in

the direct page for more frequently used registers and variables. The registers control system level features as given in Table 8.

4.5 MCU Parameter Registers

The 64 bytes of parameter registers are located at addresses $0050 through $008F. These registers are powered up at all times

and may be used to store temporary or history data during the times that the MCU is in any of the ST OP modes. The pa rameter

4.6 MCU RAM

The FXTH870xD includes static RAM. The locations in RAM below $0100 can be accesse d us ing the more efficient dire ct

addressing mode, and any single bit in this area can be accessed with the bit-manipulation instructions (BCLR, BSET, BRCLR,

and BRSET). Locating the most frequently accessed program variables in this area of RAM is preferred.

The RAM retains data when the MCU is in low-power W AIT, STOP3 or STOP4 modes. At power-on or after wakeup from STOP1,

the contents of RAM are not initialized. RAM data is unaffected by any reset provided that the supply voltage does not drop below

the minimum value for RAM retention (VRAM).

When security is enabled, the RAM is considered a secure memory resource and is not accessible through BDM or through code

executing from non-secure memory. See Section 4.8 for a detailed description of the security feature.

Table 8. MCU High Address Register Summary

AddressRegister NameBit 7654321Bit 0

$1800 SRS POR PIN COP ILOP ILAD PWU LVD 0

$1801 SBDFR 0000000BDFR

$1802 SIMOPT1 COPE COPCLKS STOPE RFEN TRE TRH BKGDPE 1

$1803 SIMOPT2 0 COPT[2:0] LFOSEL TCLKDIV BUSCLKS[1:0]

$1804 Reserved

$1805 Reserved

$1806 SDIDH REV[3:0] ID[11:8]

$1807 SDIDL ID[7:0]

$1808 SRTISC RTIF RTIACK RTICLKS RTIE 0RTIS{2:0]

$1809 SPMSC1 LVDF LVDACK LVDIE LVDRE LVDSE LVDE 0BGBE

$180A SPMSC2 000PDF0 PPDACK PDC 0

$180B Reserved

$180C SPMSC3 LVWF LVWACK LVDV LVWV 0000

$180D SIMSES KBF IRQF TRF PWUF LFF RFF

$180E SOTRM SOTRM[7:0]

$180F SIMTST TRH[2:0] TRO

$1810-1F Reserved

$1820 FCDIV DIVLD PRDIV8 DIV[5:0]

$1821 FOPT KEYEN FNORED 0000 SEC0[1:0}

$1822 Reserved

$1823 FCNFG 00 KEYACC 00000

$1824 FPROT FPS[7:1] FPDIS

$1825 FSTAT FCBEF FCCF FPVIOL FACCERR 0 FBLANK 0 0

$1826 FCMD FERASE FCMD[6:0]

$1827-3F Reserved

Note: Reserved bits shown as 0 must always be written to 0.

Reserved bits shown as 1 must always be written to 1.

Shaded bits are recommended to only be controlled by firmware or factory test.

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None of the RAM locations are used directly by the firmware provided by Freescale. The firmware routines utilize RAM only

through stack operations; and the user needs to be aware of stack depth required by each routine as described in the

CodeWarrior project files supplied by Freescale.

4.7 FLASH

The FLASH memory is intended primarily for program storage. The operating program can be loade d into the FLASH memory

after final assembly of the application product using the single-wire BACKGROUND DEBUG interface. Because no special

voltages are needed for FLASH erase and programming operation s, in-application pro gramming is also possible through other

software-controlled communication paths. For a more detailed discussion of in-circuit and in-application programming, refer to

the HCS08 Family Reference Manual, Volume I, Freescale document or der number HCS08RMV1/D.

4.7.1 Features

Features of the FLASH memory include:

• User Program FLASH Size — 8192 bytes (16 pages of 512 bytes each)

• Single power supply program and erase

• Command interface for fast program and erase operation

• Up to 100,000 program/erase cycles at typical voltage and temperature

• Flexible block protection

• Security feature for FLASH and RAM

• Auto power-down for low-frequency read accesses

4.7.2 Program and Erase Times

Before any program or erase command can be accepted, the FLASH clo ck divider register (FCDIV) must be written to set the

internal clock for the FLASH module to a frequency (fFCLK) between 150 kHz and 200 kHz. This register can be written only once,

so normally this write is performed during reset initialization. FCDIV cannot be written if the access error flag, FACCERR in

FSTAT, is set. The user must ensure that FACCERR is not set before writing to the FCDIV register. One period of the resul tin g

clock (1/fFCLK) is used by the command processor to time program and erase pulses. An integer number of these timing pulses

are used by the command processor to complete a program or erase command.

Table 9 shows program and erase times. The bus clock frequency and FCDIV determine the frequency of FCLK (fFCLK). The time

for one cycle of FCLK is tFCLK =1/f

FCLK. The times are shown as a number of cycles of FCLK and as an absolute time for the

case where tFCLK =5s. Program and erase times shown include overhead for the command state machine and enabling and

disabling of program and erase voltages.

4.7.3 Program and Erase Command Execution

The steps for executing any of the commands are listed below . The FCDIV register must be initialized and any error flags cleared

before beginning command execution. The comma nd execution steps are:

1. Write a data value to an address in the FLASH array. The address and data information from this write is latched into

the FLASH interface. This wr ite is a required first step in any command sequence. For erase and blank check

commands, the value of the data is not important. For page erase commands, the address may be any address in the

512-byte page of FLASH to be erased. For mass erase and blank check commands, the address can be any address

in the FLASH memory. Whole pages of 512 bytes are the smallest block of FLASH that may be erased.

Do not program any byte in the FLASH more than once after a successful erase operation. Reprogramming bits to a

byte which is already programmed is not allowed without fi rst erasing the page in which the byte resides or mass

erasing the entire FLASH memory. Programming without first erasing may disturb data stored in the FLASH.

Table 9. Program and Erase Times

Parameter Cycles of FCLK Time if FCLK = 200 kHz

Byte program 9 45 s

Byte program (burst) 4 20 s(1)

1. Excluding start/end overhead

Page erase 4000 20 ms

Mass erase 20,000 100 ms

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2. Write the command code for the desired command to FCMD. The five valid commands are blank check (0x05), byte

program (0x20), burst program (0x25), page erase (0x40), and mass erase (0x41). The command code is latched into

the command buffer.

3. Write a 1 to the FCBEF bit in FSTAT to clear FCBEF and launch the command (incl uding its address and data

information).

A partial command sequence can be aborted manually by writing a 0 to FCBEF any time after the write to the memory array and

before writing the 1 that clears FCBEF and launches the complete command. Aborting a command in this way sets the FACCERR

access error flag which must be cleared before starting a new command.

A strictly monitored procedure must be obeyed or the command will not be accepted. This minimizes the possibility of any

unintended changes to the FLASH memory contents. The command complete flag (FCCF) indicates when a command is

complete. The command sequence must be completed by clearing FCBEF to launch the command. Figure 9 is a flowchart for

executing all of the commands except for burst programming. The FCDIV register must be initialized before using any FLASH

commands. This must be done only once following a reset.

4.7.4 Burst Program Execution

The burst program command is used to program sequential bytes of data in less time than would be required using the standard

program command. This is possible because the high voltage to the FLASH array does not need to be disabled between program

operations. Ordinarily, when a program or erase command is issued, an in ternal charge pump associated with the FLASH

memory must be enabled to supply high voltage to the array. Upon completion of the command, the charge pump is turned off.

When a burst program command is issued, the charge pump is enabled and then remains enabled after completion of the burst

program operation i f these two conditions are met:

• The next burst program command has been queued before the current program operation has completed.

• The next sequential address selects a byte on the same physical row as the current byte being programmed. A row of FLASH

memory consists of 64 bytes. A byte within a row is selected by addresses A5 through A0. A new row begins when addresses

A5 through A0 are all zero.

The first byte of a series of sequential bytes being programmed in burst mode will take the same amount of time to program as

a byte programmed in standard mode. Subsequent bytes will program in the burst program time provided that the conditions

above are met. In the case the next sequential address is the beginning of a new row, the program time for that byte will be the

standard time instead of the burst time. This is because the high voltage to the array must be disabled and then enabled again.

If a new burst command has not been queued before the current command completes, then the charge pump will be disa bled

and high voltage removed from the array.

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Figure 9. FLASH Program and Erase Flowchart

Programming time for the FLASH through the BDM function is dependent on the specific external BDM interface tool and

software being used. Consult tool vendor for pro gramming times.

START

WRITE TO FLASH

TO BUFFER ADDRESS AND DATA

WRITE COMMAND TO FCMD

YES

FPVIOL OR

WRITE 1 TO FCBEF

TO LAUNCH COMMAND

AND CLEAR FCBEF (2)

0FCCF?

ERROR EXIT

DONE

Note 2: Wait at least four bus cycles

FACCERR?

CLEAR ERROR

FACCERR?

WRITE TO FCDIV (1) Note 1: Required only once after reset.

before checking FCBEF or FCCF.

FLASH PROGRAM AND

ERASE FLOW

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Figure 10. FLASH Burst Program Flowchart

4.7.5 Access Errors

An access error occurs whenever the command execution protocol is violated.

Any of the following specific actions will cause the access error flag (F ACCERR) in FSTA T to be set. F ACCERR must be cleared

by writing a 1 to FACCERR in FSTAT before any command can be processed.

• Writing to a FLASH address before the internal FLASH clock frequency has been set by writing to the FCDIV register

• Writing to a FLASH address while FCBEF is not set (A new command cannot be started until the command buffer is empty.)

• Writing a second time to a FLASH address before launching the previous command (There is only one write to FLASH for

every command.)

• Writing a second time to FCMD before launching the previous command (There is only one write to FCMD for every

command.)

• Writing to any FLASH control register other than FCMD after writing to a FLASH address

• Writing any command code other than the five allowed codes (0x05, 0x20, 0x25, 0x40, or 0x41) to FCMD

• Accessing (read or write) any FLASH control register other than the write to FSTAT (to clear FCBEF and launch the

command) after writing the command to FCMD.

• The MCU enters STOP mode while a program or erase command is in progress (The command is aborted.)

FCBEF?

START

WRITE TO FLASH

TO BUFFER ADDRESS AND DATA

WRITE COMMAND ($25) TO FCMD

YES

FPVIO OR

WRITE 1 TO FCBEF

TO LAUNCH COMMAND

AND CLEAR FCBEF (2)

YESNEW BURST COMMAND?

0FCCF?

ERROR EXIT

DONE

Note 2: Wait at least four bus cycles before

FACCERR?

CLEAR ERROR

FACCERR?

Note 1: Required only once after reset.

WRITE TO FCDIV (1)

checking FCBEF or FCCF.

FLASH BURST

PROGRAM FLOW

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• Writing the byte program, burst program, or page erase command code (0x20, 0x25, or 0x40) with a BACKGROUND

DEBUG command while the MCU is secured (the BACKGROUND DEBUG controller can only do blank check and mass

erase commands when the MCU is secure.)

• Writing 0 to FCBEF to cancel a partial command.

4.7.6 FLASH Block Protection

The block protection feature prevents the protected region of FLASH from program or erase changes. Block protection is

controlled through the FLASH Protection Register (FPROT). Whe n enabled, block protection begins at any 512-byte boundary

below the last address of FLASH, 0xFFFF. (see Section 4.9.4).

After exit from reset, FPROT is loaded with the contents of the NVPROT location which is in the nonvolatile register block of the

FLASH memory. FPROT cannot be changed directly from application software so a runaway program cannot alter the block

protection settings. Because NVPROT is within the last 512 bytes of FLASH, if any amount of memory is protected, NVPROT is

itself protected and cannot be altered (intentionally or unintentionally) by the application software. FPROT can be written through

BACKGROUND DEBUG commands which allows a way to erase and reprogram a protected FLASH memory.

The block protection mechanism is illustrated below. The FPS bits are used as the upper bits of the last address of unprotected

memory. This addre ss is formed by concatenating FPS7:FPS1 with logic 1 bits as shown. For example, in order to protect the

last 8192 bytes of memory (addresses 0xE000 through 0xFFFF), the FPS bits must be set to 1 101 111 which results in the value

0xDFFF as the last address of unprotected memory . In addition to programming the FPS bits to the appropriate value, FPDIS (bit

0 of NVPROT) must be programmed to logic 0 to enable block protection. Therefore the value 0xDE must be programmed into

NVPROT to protect addresses 0xE000 through 0xFFFF.

Figure 11. Block Protection Mechanism

One use for block prote c tion is to block protect an area of FLASH memory for a bootloader program. This bootlo ader program

then can be used to erase the rest of the FLASH memory and reprogram it. Because the bootloader is protected, it remains intact

even if MCU power is lost in the middle of an erase and reprogram operation.

4.7.7 Vector Redirection

NOTE

Not recommended for TPMS applicatio ns where Freescale firmware has been included in

the final image.

Whenever any block protection is enabled, the reset and interrupt vectors will be protected. Vector redirection allows users to

modify interrupt vector information without unprotecting bootloader and reset vector space. Vector redirection is enabled by

programming the FNORED bit in the NVOPT register located at address 0xFFBF to zero. For redirection to occur, at least some

portion but not all of the FLASH memory must be block protected by programmin g the NVPROT register located at address

0xFFBD. All of the interrupt vectors (memory locations 0xFFC0–0xFFFD) are redirected, though the reset vector (0xFFFE:FFFF)

is not.

For example, if 512 bytes of FLASH are protected, the protected address region is from 0xFE00 through 0xFFFF. The interrupt

vectors (0xFFC0–0xFFFD) are redirected to the locations 0xFDC0–0xFDFD. Now, if an SPI interrupt is taken for instance, the

values in the locations 0xFDE0:FDE1 are used for the vector instead of the values in the locations 0xFFE0:FFE1. This allows

the user to reprogram the unprotected portion of the FLASH with new program code including new interrupt vector values while

leaving the protected area, which inclu des the default vector locations, unchanged.

FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1

A15 A14 A13 A12 A11 A10 A9 A8

A7 A6 A5 A4 A3 A2 A1 A0

11111111

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4.8 Security

The FXTH870xD includes circuitry to prevent unauthorized access to the contents of FLASH and RAM memory. When security

is engaged, FLASH and RAM are considered secure resources. Direct-page registers, high-page registers, and the

BACKGROUND DEBUG controller are considered unsecured resour ces. Programs executing within secure memory have

normal access to any MCU memory locations and resources. Attempts to access a secure memory location with a program

executing from an unsecured memory space or through the BACKGROUND DEBUG interface are blocked (writes are ignored

and reads return all 0s).

Security is engaged or disengaged based on th e state of two nonvolatile register bits (SEC0[1:0]) in the FOPT register. During

reset, the contents of the nonvolatile location NVOPT are copied from FLASH into the working FOPT register in high-page

memory is programmed. The 1:0 state disengages security and the other three combinations engage security . Notice the erased

state (1:1) makes the MCU secure. During development, whenever the FLASH is erased, it is good practice to immediately

program the SEC00 bit to 0 in NVOPT so SEC[1:0] = 1:0. This would allow th e MCU to remain unsecured after a subsequent

reset.

The on-chip debug module cannot be enabled while the MCU is secure. The separate BACKGROUND DEBUG controller can

still be used for background memory access commands, but the MCU cannot enter ACTIVE BACKGROUND mode except by

holding BKGD/MS low at the rising edge of reset.

A user can choose to allow or disallow a security unlocking mechanism through an 8-byte backdoor security key . If the nonvolatile

KEYEN bit in NVOPT/FOPT is 0, the backdoor key is disabled and there is no way to disengage security without completely

erasing all FLASH locations. If KEYEN is 1, a secure user program can temporarily disengage security by:

1. Writing 1 to KEYACC in the FCNFG register. This make s the FLASH mo dule interpret writes to the backdoor

comparison key locations (NVBACKKEY through NVBACKKEY+7) as values to be compared against the key rather

than as the first step in a FLASH program or erase comman d.

2. Writing the user-entered key values to the NVBACKKEY through NVBACKKEY+7 locations. These writes must be

done in order starting with the value for NVBACKKEY and ending with NVBACKKEY+7. STHX must not be used for

these writes because these writes cannot be done on adjacent bus cycles. User software normally would get the key

codes from outside the MCU system through a communication interface such as a serial I/O.

3. Writing 0 to KEYACC in the FCNFG register. If the 8-byte ke y that was just written matches the key stored in the

FLASH locations, SEC[1:0] are automatically changed to 1:0 and security will be disengaged until the next reset.

The security key can be written only from secure memory (either RAM or FL ASH), so it cannot be entered through

BACKGROUND commands without the cooperation of a secure user program.

The backdoor comparison key (NVBACKKEY through NVBACKKEY+7) is located in FLASH memory locations in the nonvolatile

nonvolatile registers are in the same 512-byte block of FLASH as the reset and interrupt vectors, so block protecting that space

also block protects the backdoor comparison key. Block protects cannot be changed from user application programs, so if the

vector space is block protected, the backdoor security key mechanism cannot permanently change the block protect, security

settings, or the backdoor key.

Security can always be disengaged through the BACKGROUND DEBUG interface by taking these steps:

1. Disable any block protections by writing FPROT. FPROT can be written only with BACKGROUND DEBUG commands,

not from application software.

2. Mass erase FLASH if necessary.

3. Blank check FLASH. Provided FLASH is compl etely erased, security is disengaged until the next reset.

To avoid returning to secure mode after the next reset, program NVOPT so SEC[1:0] = 1:0.

NOTE

Enabling the security feature disables Freescale ability to perform failu re analysis without

first completely erasing all flash memory contents. If the security feature is implemented,

customer shall be responsible for providing to Freescale unsecured parts for any failure

analysis to begin or supplying the entire contents of the device flash memory data as part of

the return process, to allow Freescale to erase and subsequently restore the device to its

original condition.

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4.9 FLASH Registers and Control Bits

The FLASH module has nine 8-bit registers in the high-page register space, three locations in the nonvolatile register space in

FLASH memory which are copied into three corresponding high-page control registers at reset. There is also an 8-byte

comparison key in FLASH memory. Refer to Table 8 and Table 9 for the absolute address assignments for all FLASH registers.

This section refers to registers and control bits only by their names. A Freescale Semiconductor-provided equate or header file

normally is used to translate these names into the appropriate absolute addresses.

4.9.1 FLASH Clock Divider Register (FCDIV)

Bit 7 of this register is a read-only status flag. Bits 6 through 0 can be read at any time but can be written only once. Before any

erase or programming operations are possible, write to this register to set the frequency of the clock for the nonvolatile memory

system within acceptable limits.

$1820 7 6 5 4 3 2 1 0

RDIVLD PRDIV8 DIV5 DIV4 DIV3 DIV2 DIV1 DIV0

Reset: 00000000

= Reserved

Figure 12. FLASH Clock Divider Register (FCDIV)

Table 10. FCDIV Register Field Descriptions

Field Description

DIVLD

Divisor Loaded Status Fl ag — When set, this read-only status flag indicates that the FCDIV register has been written since

reset. Reset clears this bit and the first write to this register causes this bit to become set regardless of the data written.

0 FCDIV has not been written since reset; erase and program operations disabled for FLASH

1 FCDIV has been written since reset; erase and program operations enabled for FLASH

PRDIV8

Prescale (Divide) FLASH Clock by 8

0 Clock input to the FLASH clock divider is the bus rate clock

1 Clock input to the FLASH clock divider is the bus rate clock divided by 8

5:0

DIV[5:0]

Divisor for FLASH Clock Divider — The FLASH clock divider divides the bus rate clock (or the bus rate clock divided by 8 if

PRDIV8 = 1) by the value in the 6-bit DIV5:DIV0 field plus one. The resulting frequency of the internal FLASH clock must fall

within the range of 200 kHz to 150 kHz for proper FLASH operations. Program/Erase timing pulses are one cycle of this internal

FLASH clock which corresponds to a range of 5 s to 6.7 s. The automated programming logic uses an integer number of

these pulses to complete an erase or program operation.

• if PRDIV8 = 0 — fFCLK = fBus  ([DIV5:DIV0] + 1)

• if PRDIV8 = 1 — fFCLK = fBus  (8  ([DIV5:DIV0] + 1))

Table 11 shows the appropriate values for PRDIV8 and DIV5:DIV0 for selected bus frequencies.

Table 11. FLASH Clock Divider Settings

fBus PRDIV8

(Binary) DIV5:DIV0

(Decimal) fFCLK Program/Erase Timing Pulse

(5 s Min, 6.7s Max)

20 MHz 1 12 192.3 kHz 5.2 s

10 MHz 0 49 200 kHz 5 s

8 MHz 0 39 200 kHz 5 s

4 MHz 0 19 200 kHz 5 s

2 MHz 0 9 200 kHz 5 s

1 MHz 0 4 200 kHz 5 s

200 kHz 0 0 200 kHz 5 s

150 kHz 0 0 150 kHz 6.7 s

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4.9.2 FLASH Options Register (FOPT and NVOPT)

During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into FOPT. Bits 5 through 2 are not used

and always read 0. This register may be read at any time, but writes have no meaning or effect. To change the value in this

4.9.3 FLASH Configuration Register (FCNFG)

Bits 7 through 5 can be read or written at any time. Bits 4 through 0 always read 0 and cannot be written.

$1821 7 6 5 4 3 2 1 0

RKEYEN FNORED 0 0 0 0 SEC01 SEC00

Reset: This register is loaded from nonvolatile location NVOPT during reset.

= Reserved

Figure 13. FLASH Options Register (FOPT)

Table 12. FOPT Reg ister Field Descriptions

Field Description

KEYEN

Backdoor Key Mechanism Enable — When this bit is 0, the backdoor key mechanism cannot be used to disengage security .

The backdoor key mechanism is accessible only from user (secured) firmware. BDM commands cannot be used to write key

comparison values that would unlock the backdoor key . For more detailed information about the backdoor key mechanism, refer

to Section 4.8.”

0 No backdoor key access allowed

1 If user firmware writes an 8-byte value that matches the nonvolatile backdoor key (NVBACKKEY through NVBACKKEY+7

in that order), security is temporarily disengaged until the next MCU reset

FNORED

Vector Redirection Disable — When this bit is 1, then vector redirection is disabled.

0 Vector redirection enabled

1 Vector redirection disabled

1:0

SEC0[1:0]

Security State Code — This 2-bit field determines the security state of the MCU as shown in Table 13. When the MCU is

secure, the contents of RAM and FLASH memory cannot be accessed by instructions from any unsecured source including the

BACKGROUND DEBUG interface. For more detailed information about security, refer to Section 4.8. SEC01:SEC00 changes

to 1:0 after successful backdoor key entry or a successful blank check of FLASH.

Table 13. Security States

SEC01:SEC00 Description

0:0 secure

0:1 secure

1:0 unsecured

1:1 secure

$1823 7 6 5 4 3 2 1 0

R00

KEYACC 00000

Reset: 0 000 0 000

= Reserved

Figure 14. FLASH Configuration Register (FCNFG)

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4.9.4 FLASH Protection Register (FPROT and NVPROT)

During reset, the contents of the nonvolatile location NVPROT is copied from FLASH into FPROT. Bits 0, 1, and 2 are not used

and each always reads as 0. This register can be read at any time, but user program writes have no meaning or effect.

BACKGROUND DEBUG commands can write to FPROT.

Figure 15. FLASH Protection Register (FPROT)

4.9.5 FLASH Status Register (FSTAT)

Bits 3, 1, and 0 always read 0 and writes have no meaning or effect. The remaining five bits are status bits that can be read at

any time. Writes to these bits have special meanings that are discussed in the bit descriptions.

Table 14. FCNFG Register Field Descriptions

Field Description

KEYACC

Enable Writing of Access Key — This bit enables writing of the backdoor comparison key . For more detailed information about

the backdoor key mechanism, refer to Section 4.8.

0 Writes to 0xFFB0–0xFFB7 are interpreted as the start of a FLASH programming or erase command

1 Writes to NVBACKKEY (0xFFB0–0xFFB7) are interpreted as comparison key writes

$1824 7 6 5 4 3 2 1 0

RFPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1 FPDIS

W(1)

1. Background commands can be used to change the contents of these bits in FPROT.

(1) (1) (1) (1) (1) (1) (1)

Reset: This register is loaded from nonvolatile location NVPROT during reset.

Table 15. FPROT Register Field De scriptions

Field Description

7:1

FPS[7:1] FLASH Protect Select Bits — When FPDIS = 0, this 7-bit field determines the ending address of unprotected FLASH locations

at the high address end of the FLASH. Protected FLASH locations cannot be erased or programmed.

FPDIS

FLASH Protection Disable

0 FLASH block specified by FPS[7:1] is block protected (program and erase not allowed)

1 No FLASH block is protected

$1825 7 6 5 4 3 2 1 0

RFCBEF FCCF FPVIOL FACCERR 0 FBLANK 0 0

Reset: 11000000

= Reserved

Figure 16. FLASH Status Register (FSTAT)

Table 16. FSTAT Register Field Descriptions

Field Description

FCBEF

FLASH Command Buffer Empty Flag — The FCBEF bit is used to launch commands. It also indicates that the command

buffer is empty so that a new command sequence can be executed when performing burst programming. The FCBEF bit is

cleared by writing a one to it or when a burst program command is transferred to the array for programming. Only burst program

commands can be buffered.

0 Command buffer is full (not ready for additional commands)

1 A new burst program command can be written to the command buffer

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4.9.6 FLASH Command Register (FCMD)

Only five command codes are recognized in normal user modes as shown in Table 17. Refer to Section 4.7.3, for a detailed

discussion of FLASH programming and erase operations.

All other command codes are illegal and generate an access error.

It is not necessary to perform a blank check command after a mass erase operation. Only blank check is required as part of the

security unlocking mechanism.

FCCF

FLASH Command Complete Flag — FCCF is set automatically when the command buffer is empty and no command is being

processed. FCCF is cleared automatically when a new command is started (by writing 1 to FCBEF to register a command).

Writing to FCCF has no meaning or effect.

0 Command in progress

1 All commands complete

FPVIOL

Protection Violation Flag — FPVIOL is set automatically when FCBEF is cleared to register a command that attempts to erase

or program a location in a protected block (the erroneous command is ignored). FPVIOL is cleared by writing a 1 to FPVIOL.

0 No protection violation

1 An attempt was made to erase or program a protected location

FACCERR

Access Error Flag — FACC ERR is set automatically when the proper command sequence is not obeyed exactly (the

erroneous command is ignored), if a program or erase operation is attempted before the FCDIV register has been initialized,

or if the MCU enters STOP while a command was in progress. For a more detailed discussion of the exact actions that are

considered access errors, see Section 4.7.5. FACCERR is cleared by writing a 1 to FACCERR. Writing a 0 to FACCER R has

no meaning or effect.

0 No access error

1 An access error has occurred

FBLANK

FLASH Verified as All Blank (erased) Flag — FBLANK is set automatically at the conclusion of a blank check command if

the entire FLASH array was verified to be erased. FBLANK is cleared by clearing FCBEF to write a new valid command. Writing

to FBLANK has no meaning or effect.

0 After a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the FLASH array is not completely erased

1 After a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the FLASH array is completely erased

(all 0xFF)

$1826 7 6 5 4 3 2 1 0

R00000000

WFCMD7 FCMD6 FCMD5 FCMD4 FCMD3 FCMD2 FCMD1 FCMD0

Reset: 00000000

Figure 17. FLASH Command Register (FCMD)

Table 17. FLASH Commands

Command FCMD Equate File Label

Blank check 0x05 mBlank

Byte program 0x20 mByteProg

Byte program — burst mode 0x25 mBurstProg

Page erase (512 bytes/page) 0x40 mPageErase

Mass erase (all FLASH) 0x41 mMassErase

Table 16. FSTAT Register Field De scriptions (continued)

Field Description

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5 Reset, Interrupts and System Configuration

This section discusses basic reset and interrupt mechanisms and the various sources of reset and interrupts in the FXTH870xD.

Some interrupt sources from peripheral modules are discussed in greater detail within other sections of this product specification.

This section gathers basic information about all reset and interrupt sources in one place for easy reference. A few reset and

interrupt sources, including the computer operating properly (COP) watchdog and real-time interrupt (RTI), are not part of on-chip

peripheral systems, but are part of the system control logic.

5.1 Features

Reset and interrupt features include:

• Multiple sources of reset for flexible system configuration and reliable operation

• Reset status register (SRS) to indicate source of most recent reset

• Separate interrupt vectors for each module (reduces polling overhead)

5.2 MCU Reset

Resetting the MCU provides a way to start processing from a known set of initial conditions. During reset, most control and status

registers are forced to initial values and the program counter is loaded from the reset vector ($DFFE:$DFFF). On-chip peripheral

modules are disabled and any I/O pins are initially configured as general-purpose high-impedance inputs with any pullup devices

disabled. The I bit in the condition code register (CCR) is set to block maskable interrupts so the user program has a chance to

initialize the stack pointer (SP) and system control settings. The SP is forced to $00FF at reset. The FXTH870xD has seven

sources for reset:

• Power-on reset (POR)

• Low-voltage detect (LVD)

• Computer operating properly (COP) timer

• Periodic hardware reset (PRST)

• Illegal opcode detect

• Illegal address dete ct

• BACKGROUND DEBUG forced reset

Each of these sources has an associated bit in the system reset status register with the exception of the BACKGROUND DEBUG

forced reset and the periodic hardware reset, PRST, that is indicated by the PRF bit in the PWUCS1 register.

5.3 Computer Operating Properly (COP) Watchdog

The COP watchdog is intended to force a system reset when the application software fails to execute as expected. To prevent a

system reset from the COP timer (when it is enabled), application software must reset the COP timer periodically. If the

application program gets lost and fails to reset the COP before it times out, a system reset is generated to force the system back

to a known starting point. The COP watchdog is enabled by the COPE bit in SIMOPT1 register . The COP timer is reset by writing

any value to the address of SRS. This write does not affect the data in the read-only SRS. Instea d, the act of writing to this

address is decoded and sends a reset signal to the COP timer.

The timeout period can be selected by the COPCLKS and the COPT[2:0] bits as shown in Table 18. The COPCLKS bit selects

either the LFO or the CPU bus clock as the clocking source and the COPT[2:0] bit s select the clock count required for a timeout.

The tolerances of these ti meout periods is dependent on the selected clock source (LFO or HFO).

Table 18. COP Watchdog Timeout Peri od

COPCLKS COPT Clock

Source

COP

Overflow

Count

COP Overflow Time

(ms, nominal)

210

0 000 LFO 2

532

0 001 LFO 2

664

0 010 LFO 2

7128

0 011 LFO 2

8256

0 100 LFO 2

9512

0 101 LFO 2

10 1024

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After any reset, the COP timer is enabled. This provides a reliable way to detect code that is not executing as intended. If the

COP watchdog is not used in an application, it can be disabled by clearing the COPE bit in the write-once SIMOPT1 register.

Even if the application will use the reset default settings in COPE, COPCLKS and COPT[2:0], the user should still write to write-

once SIMOPT1 during reset initialization to lock in the settings. That way, they cannot be changed accidentally if the application

program gets lost.

The write to SRS that services (clears) the COP timer should not be placed in an interrupt service routine (ISR) because the ISR

could continue to be executed periodically even if the main application program fails. When the MCU is in ACTIVE

BACKGROUND DEBUG mode, the COP timer is temporarily disabled.

5.4 SIM Test Register (SIMTST)

The output of the temperature monitor is available using the SIM Test register as shown in Figure 18.

0 110 LFO 2

11 2048

0 111 LFO 2

11 2048

BUSCLKS[1:0]

1:1 (0.5 MHz) 1:0 (1 MHz) 0:1 (2 MHz) 0:0 (4MHz)

1 000Bus Clock 2

13 16.384 8.192 4.096 2.048

1 001Bus Clock 2

14 32.768 16.384 8.192 4.096

1 010Bus Clock 2

15 65.536 32.768 16.384 8.192

1 011Bus Clock 2

16 131.072 65.536 32.768 16.384

1 100Bus Clock 2

17 262.144 131.072 65.536 32.768

1 101Bus Clock 2

18 524.288 262.144 131.072 65.536

1 110Bus Clock 2

19 1048.576 524.288 262.144 131.072

1 111Bus Clock 2

19 1048.576 524.288 262.144 131.072

$180F Bit 7 654321Bit 0

RTRH TRO

RESET: 00111001

= Reserved

Figure 18. SIM Test Register (SIMTST)

Table 19. SIMTST Register Field Descriptions

Field Description

reserved Reserved Bit — These bits are reserved for factory trim and should not be altered by the user.

6:4

TRH Temperature Restart High threshold — Binary coded from 0x00 to 0x07; recommend applications overwrite to 0x06 at each

wakeup cycle.

3:1

reserved Reserved Bit — These bits are reserved for factory trim and should not be altered by the user.

TRO

Temperature Restart Outside

1 TR module is outside the TREARM temperature range and will restart the MCU if the TRE bit is set and

temperature falls back within the TRESET temperature range.

0 TR module is within the TRESET temperature range and the MCU cannot be armed to restart when

temperature falls back to the TRESET range. The TRE bit cannot be set.

Table 18. COP Watchdog Timeout Period (continued)

COPCLKS COPT Clock

Source

COP

Overflow

Count

COP Overflow Time

(ms, nominal)

210

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5.5 Interrupts

Interrupts provide a way to save the current CPU status and registers, execute an interrupt service routine (ISR), and then restore

the CPU status so processing resumes where it left off before the interrupt. Other than the software interrupt (SWI), which is a

program instruction, interrupts are caused by hardware events. The debug module ca n also generate an SWI under certain

circumstances.

If an event occurs in an enabled interrupt source, an associated read-only status flag will become set. The CPU will not respond

until and unless the local interrupt enable is a logic 1 to enable the interrupt. The I bit in the CCR must be a logic 0 to allow

interrupts. The global interrupt mask (I bit) in the CCR is initially set after reset which masks (prevents) all maskable interrupt

sources. The user program initializes the stack pointer and performs other system setup before clearing the I bit to allow the CPU

to respond to interrupts. When the CPU receives a qualified interrupt request, it completes the current inst ru cti o n be fore

responding to the interrupt. The interrupt sequence follows the same cycle-by-cycle sequence as the SWI instruction and consists

of:

• Saving the CPU registers on the stack

• Setting the I bit in the CCR to mask further interrupts

• Fetching the interrupt vector for the highest-priority interrupt that is currently pending

• Filling the instruction queue with the first th ree bytes of program info rmation starting from the address fetched from the

interrupt vector locations

While the CPU is responding to the interrupt, the I bit is automatically set to avoid the possibility of another interrupt interrupting

the ISR itself (this is called nesting of interrupts). Normally, the I bit is restored to 0 when the CCR is restored from the value

stacked on entry to the ISR. In rare cases, the I bit may be cleared inside an ISR (after clearing the status flag that generated the

interrupt) so that other interrupts can be serviced without waiting for the first service routine to finish. This practice is not

recommended for anyone other than the most experienced programmers because it can lead to subtle program errors that are

difficult to debug.

The interrupt service routine ends with a return-from-interrupt (RTI) instruction which restores the CCR, A, X, and PC registers

to their pre interrupt values by reading the previously saved information off the stack.

When two or more interrupts are pending when the I bit is cleared, the highest priority sou rce is serviced first.

For compatibility with the M68HC08, the H regi ster is not automatically saved and restored. It is good programming practice to

push H onto the stack at the start of the interrupt service routine (ISR) and restore it just before the RTI that is used to return from

the ISR.

5.5.1 Interrupt Stack Frame

Figure 18 shows the contents and organization of a stack frame. Before the interrupt, the stack pointer (SP) points at the nex t

available byte location on the stack. The current values of CPU registers are stored on the stack starting with the low-order byte

of the program counter (PCL) and ending with the CCR. After stacking, the SP points at the next available location on the stack

which is the address that is one less than the address where the CCR was saved. The PC value that is stacked is the address

of the instruction in the main program that would have execu te d next if the interrupt had not occurred.

When an RTI instruction is executed, these values are recovered from the stack in reverse order. As part of the RTI sequ ence,

the CPU fills the instruction pipeline by reading three bytes of program information, starting from the PC address just recovered

from the stack.

The status flag causing the interrupt must be acknowledged (cleared) before returning from the ISR. T ypically, the flag should be

cleared at the beginning of the ISR so that if another interrupt is generated by this same source, it will be registered so it can be

serviced after completion of the current ISR.

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Figure 19. Interrupt Stack Frame

5.5.2 Vector Summary

Table 20 provides a summary of all interrupt sources. Higher-priority sources are located toward the bottom of the table (at the

higher vector addresses). All of these vectors are a 2-byte address that the firmware uses as the destination address. This allows

the firmware to intercept all vectors and add additional processing as needed. The additional process latency for each interrupt

will be described in Section 14.

Therefore, the high-order byte of the address for the user’s interrupt service routine is located at the lower address in the vector

address column, and the low-order byte of the address for the interrupt service routine is located at the higher address. When an

interrupt co ndition occu rs, an associ ated flag b it becom es set. If the associated local interrupt enable is set, an interrupt request

is sent to the CPU. Within the CPU, if the global interrupt mask (I bit in the CCR) is 0, the CPU will finish the current instruction,

stack the PCL, PCH, X, A, and CCR CPU registers, set the I bit, and then fetch the interrupt vector for the highest priority pending

interrupt. Processing then continues in the inte rrupt service routine.

The triggering of any of these vector fetches wil l wake the MCU from any of the STOP modes.

CONDITION CODE REGISTER

ACCUMULATOR

INDEX REGISTER* (LOW BYTE X)

PROGRAM COUNTER HIGH

PROGRAM COUNTER LOW

UNSTACKING

ORDER

STACKING

ORDER

SP before

the interrupt

SP after

interrupt stacking

Towards HIG HER Addres ses

Towards LOWER Addresses

* High byte (H) of index register is not automatically stacked.

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Table 20. Vector Summary

Vector

Priority Vector

No.

Jump Table

Vector Addr

(High/Low)

Vector

Name Module

Source Flags Enables Description

Lower

Higher

15 $DFE0 - $DFE1 Vkbi KBI KBF KBIE Keyboard interrupt pins PTA[3:0]

14 $DFE2 - $DFE3 Reserved

13 $DFE4 - $DFE5 Reserved

12 $DFE6 - $DFE7 Vrti Sys Ctrl RTIF RTIE Interrupt from the RTI when the periodic

wakeup timer has timed out.

11 $DFE8 - $DFE9 Vlfrcvr LFR

LFIDF LFIDIE Interrupt from LFR in data mode when a valid

wake ID has been received .

LFCDF LFCDIE Interrupt from LFR in carrier mode when a

carrier present for the r equired time.

LFERF LFERIE Interrupt from LFR in the manchester decode

mode when an error is detected.

LFDRF LFDRIE Interrupt from LFR in the manchester decode

mode when an 8-bit data byte has been

successfully received.

10 $DFEA - $DFEB Reserved

9 $DFEC - $DFED Vrf RFM RFIF RFIEN

Interrupt from the RFM when the data buffer

has been completely sent.

RFEF Interrupt from the RFM when transmission

error detected.

8$DFEE - $DFEF Reserved

7 $DFF0 - $DFF1 Vtpm1ovf TPM1 TOF TOIE Interrupt from the TPM1 when the timer

overflows.

6 $DFF2 - $DFF3 Vtpm1ch1 TPM1 CH1F CH1IE Interrupt from the TPM1 when the selected

event for channel 1 occurs.

5 $DFF4 - $DFF5 Vtpm1ch0 TPM1 CH0F CH0IE Interrupt from the TPM1 when the selected

event for channel 0 occurs.

4 $DFF6 - $DFF7 Vwuktmr PWU WUKI WUK[5:0] Interrupt from the PWU when the wakeup time

interval has elapsed.

3 $DFF8 - $DFF9 Vlvd Sys Ctrl LVDF LVDIE Interrupt from the LVD when the supply

voltage has dropped below the L VD threshold.

2$DFFA - $DFFB Reserved

1 $DFFC - $DFFD Vswi SWI opcode — — Interrupt from the CPU when an SWI

instruction has been executed.

0 $DFFE -$DFFF Vreset

Sys Ctrl - POR — — Reset from power on sequence.

Sys Ctrl - PRF PRF PRST[5:0] Reset from PWU when the reset interval

elapsed.

Sys Ctrl - COP — COPE Reset when COP watchdog times out.

Sys Ctrl - LVD — LVDRE Reset from the LVD when the supply voltage

has dropped below the LVD threshold.

Temp Restart — TRE Reset when the temperature falls below the

temperature restart threshold

Illegal opcode — — Reset from the CPU when trying to execute an

illegal opcode.

Illegal address — — Reset from the CPU when trying to access an

illegal address.

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5.6 Low-Voltage Detect (LVD) System

The FXTH870xD includes a system to detect low voltage conditions in order to protect memory contents and control MCU system

states during supply voltage variations. The system is comprised of a power-on reset (POR) circuit and an L VD circuit with a user

selectable trip voltage, either high (VLVDH) or low (VLVDL). The LVD circuit is enabled when LVDE in SPMSC1 is high and the trip

voltage is selected by LVDV in SPMSC3. The LVD is disabled upon entering any of the STOP modes unless the LVDSE bit is

set. If LVDSE and LVDE are both set, then the MCU cannot enter STOP1.

5.6.1 Power-On Reset Operation

When power is initially applied to the FXTH87 0xD, or when the supply voltage drops below the VPOR level, the POR circuit will

cause a reset condition. As the supply voltage rises, the LVD circuit will hold the chip in reset until the supply has risen above the

level determined by LVDV bit. Both the POR bit and the LVD bit in SRS are set following a POR.

5.6.2 LVD Reset Operation

The LVD can be configured to generate a reset upon detection of a low voltage condition has occurred by setting LVDRE to 1

when the supply voltage has fallen below the level determined by L VDV bit. After an L VD reset has occurred, the LVD system will

hold the FXTH870xD in reset until the supply voltage has risen above the level determined by L VDV bit. The threshold for falling

and rising differ by a small amount of hysteresis. The LVD bit in the SRS register is set following eithe r an LVD reset or POR.

5.6.3 LVD Interrupt Operation

When a low voltage condition is detected and the LVD circuit is configured for in terrupt operation (LVDE set, LVDIE set, and

LVDRE clear), then LVDF will be set and an LVD interrupt will occur.

5.6.4 Low-Voltage Warning (LVW)

The LVD system has a low voltage warning flag, LVWF, to indicate to the user that the supply voltage is approaching, but is still

above, the LVD reset voltage. The LVWF can be reset by writing a logical one to the LVWACK bit. The LVW does not have an

interrupt associated with it. There are two user selectable trip voltages for the L VW as selected by LVWV in SPMSC3. The L VWF

is set when the supply voltage falls below the selected level and cann ot be reset until the supply voltage has risen above the

selected level. The threshold for falling and rising differ by a small amount of hysteresis.

5.7 System Clock Control

Several clock rate selections are possible with the FXTH870xD using the BUSCLKS[1:0] control bits to select the clock frequency

division of the HFO as given in Table 21. These bits are cleared by any MCU reset.

5.8 Keyboard Interrupts

The keyboard interrupts can be used to wake the MCU. These are assigned to specific general I/O pins as given in Table 22.

Table 21. HFO Frequency Selections

BUSCLKS1 BUSCLKS0 HFO Frequency

(MHz) CPU Bus Frequency (MHz)

00 8 4

01 4 2

10 2 1

11 1 0.5

Table 22. Keyboard Interrupt Assignments

KBI Pin Pin Function

0 PTA0 General I/O

1 PTA1 General I/O

2 PTA2 General I/O

3 PTA3 General I/O

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5.9 Real Time Interrupt

The RTI uses the internal low frequency oscillator (LFO) as its clock source. The RTI can be used as a periodic interrupt in MCU

RUN mode, or can be used as a periodic wakeup from all low power modes. The LFO is always active and cannot be powered

off by any soft ware control. The control bits for the RTI are shown in Figure 20.

$1808 Bit 7 6 5 4 3 2 1 Bit 0

RRTIF 0 RTICLKS RTIE 0 RTIS[2:0]

WRTIACK

RESET: 00000000

POR: 00000000

= Reserved

Figure 20. RTI Status/Co ntrol Registe r (SRTISC)

Table 23. SRTISC Register Field Descriptions

Field Description

RTIF

RTI Interrupt Flag — The RTIF bit indicates when a wakeup interrupt has been generated by the RTI. This bit is cleared by

writing a one to the RTIACK bit. Writing a zero to this bit has no effect. Reset clears this bit.

0 Wakeup interrupt not generated or was previou sly acknowledged.

1 Wakeup interrupt generated.

RTIACK

Acknowledge RTIF Interrupt Flag — The RTIACK bit clears the RTIF bit if written with a one. Writing a zero to the RTIACK bit

has no effect on the RTIF bit. Reading the RTIACK bit returns a zero. Reset has no effect on this bit.

0 No effect.

1 Clear RTIF bit.

RTICLKS

RTI Interrupt Clock Select — This read-write bit selects the clock source for the real-time interrupt request

0 Real-time interrupt request clock source is the LFO.

1 Real-time interrupt request clock source is the HFO (MCU must be in the RUN mode).

RTIE

RTIF Interrupt Enable — The RTIE bit enables RTI interrupts if written with a one. Reset clears this bit.

0 Disable RTI interrupts.

1 Enable RTI interrupts.

Unused Unused

2:0

RTIS[2:0] RTI Interrupt Delay Selects — The RTIS[2:0] bits select the timing of the RTI interrupts as given

in Table 24. Reset clears these bits.

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5.10 Temperature Sensor and Restart System

The FXTH870xD has two temperature sensing mechanisms. The first is an accurate sensor which is accessible through the

ADC10 channel 1. The second is a less accurate, very low power sensor which generates a wakeup from STOP1 when the

temperature crosses its threshold of detection. This is the temperature restart wakeup which is used as follows:

1. The temperature restart wakeup is enabled by software following detection of an over temperature condition using the

temperature sensor connected to the ADC10.

2. User software enables the temperature restart detector and then instructs the MCU to enter STOP1 mode to halt

execution during the out-of-range temperature condition.

3. When the temperature crosses the temperature restart threshold back into the normal range of operation, a wakeup is

generated to wake the MCU. Exit from STOP1 will reset the device.

The temperature sensor is enabled whenever the ADC10 is enabled. The temperature restart wakeup is enabled by setting the

TRE bit in SIMOPT1 register and whether the detector interrupts the MCU from a very low or a very high temperature is

determined by the TRH bit in the SIMOPT1 register.

5.11 Reset, Interrupt and System Control Registers And Bits

One 8-bit register in the direct page register space and eight 8-bit registers in the high-page register space are related to reset

and interrupt systems.

5.11.1 System Reset Status Register (SRS)

The SRS register at $1800 includes seven read-only status flags to indicate the source of the most recent reset. When a debug

host forces reset by writing 1 to BDFR in the SBDFR register, none of the status bits in SRS will be set. Writing any value to this

register address clears the COP watchdog timer without affecting the conten ts of this register. The rese t state of these bits

depends on what caused the MCU to reset.

Table 24. Real-Time Interrupt Period

RTIS2 RTIS1 RTIS0 Delay Timing (ms)

(Dependent on 1-kHz LFO)

000 OFF

001 2

010 4

011 8

100 16

101 32

110 64

111 128

$1800 Bit 7 6 5 4 3 2 1 Bit 0

RPOR PIN COP ILOP ILAD PWU LVD 0

POR Reset: 10000010

LVD Reset: 10000010

Any Other

Reset: 0(1)(1)(1)(1) 000

= Reserved

1. Any of these reset sources that are active at the time of reset will cause the corresponding bit(s) to be set; bits corresponding to sources that

are not active at the time of reset will be cleared.

Figure 21. System Reset Status Register (SRS)

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5.11.2 System Options Register 1 (SIMOPT1)

The following clock source and frequency selections are available using the system option register 1 as shown in Figure 22.

Table 25. SRS Register Field Descriptions

Field Description

POR

Power-On Reset — This bit indicates reset was caused by the power-on detection logic. Because the internal supply voltage

was ramping up at the time, the low-voltage reset (L VR) status bit is also set to indicate that the reset occurred while the internal

supply was below the LVR threshold.

0 Reset not caused by POR

1 POR caused reset

External Reset Pin — This bit indicates reset was caused by an active-low level on the external reset pin if the device was in

either the STOP1 or RUN modes. This bit is not set if the external reset pin is pulled low when the device is in the STOP1 mode.

0 Reset not caused by external reset pin

1 Reset came from external reset pin

COP

Computer Operating Properly (COP) Watchdog — This bit indicates that reset was caused by the COP watchdog timer timing

out. This reset source may be blocked by COPE = 0.

0 Reset not caused by COP timeout

1 Reset caused by COP timeout

ILOP

Illegal Opcode — This bit indicates reset was caused by an attempt to execute an unimplemented or illegal opcode. The STOP

instruction is considered illegal if STOP is disabled by STOPE = 0 in the SOPT register. The BGND instruction is considered

illegal if ACTIVE BACKGROUND mode is disabled by ENBDM = 0 in the BDCSC register.

0 Reset not caused by an illegal opcode

1 Reset caused by an illegal opcode

ILAD

Illegal Address — This bit indicates reset was caused by an attempt to access either data or an instruction at an unimplemented

memory address.

0 Reset not caused by an illegal address

1 Reset caused by an illegal address

PWU

Programmable Wakeup — This bit indicates reset was caused by a PWU reset in run, WAIT, ST OP4, and STOP3. Af ter STOP1

exit, PRF in PWUCSI indicates PWU was the source of a wakeup.

0 Reset not caused by PWU.

1 Reset caused by PWU.

LVD

Low Voltage Detect — If the LVDRE and LVDSE bits are set and the supply drop s below the LVD trip voltage, an LVD reset will

occur. This bit is also set by POR.

0 Reset not caused by LVD trip or POR.

1 Reset caused by LVD trip or POR.

Unused Unused Bit — This bit always reads as a logical zero. Writes

$1802 Bit 7 6 5 4 3 2 1 Bit 0

RCOPE COPCLKS STOPE RFEN TRE TRH BKGDPE

RESET: 100-0011

= Reserved

Figure 22. System Option Register 1 (SIMOPT1)

Table 26. SIMOPT 1 Register Field Descriptions

Field Description

COPE

COP Enable — This control bit enables the COP watchdog. This bit is a write-once bit so that only the first write after reset is

honored. Reset sets the COPE bit.

0 COP Watchdog disabled.

1 COP Watchdog enabled.

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5.11.3 System Operation Register 2 (SIMOPT2)

The following clock source and frequency selections are available using the system option register 2 as shown in Figure 23.

COPCLKS

COP Clock Select — This control bit selects the clock source for the COP watchdog timer. This bit is a write-once bit so that

only the first write after reset is honored. This bit is cleared by an MCU reset.

0 Select the LFO oscillator output.

1 Select the CPU bus clock.

STOPE

STOP Mode Select — This control bit enables/disables the STOP instruction to enter a STOP mode defined by the SPMSCR2

register. This bit is a write-once bit so that only the first write after reset is honored. This bit is cleared by an MCU reset.

0 Disable STOP modes.

1 Enable STOP modes.

RFEN

RF Module Enable — This bit enables or disables the RF module. This bit is not affected by any reset or power on after ST OP

exit. It is only initialized at the first power up. This bit can be written anytime.

1 RF module enabled.

0 RF module disabled.

TRE

Temperature Restart Enable — This control bit enables the temperature restart circuit to interrupt the MCU after being

shutdown at either a very high or very low temperature. This bit is cleared by an MCU reset.

0 Temperature restart disabled.

1 Temperature restart enabled.

TRH

Temperature Restart Level — This control bit selects whether the temperature restart circuit will interrupt the MCU after being

shutdown on returning from either a very high or very low temperature. This bit is cleared by an MCU reset.

0 Temperature restart interrupts MCU on return from a very low temperature.

1 Temperature restart interrupts MCU on return from a very high temperature.

BKGDPE

BKGD Pin Enable — BKGDPE can be used to allow the BKGD/PTA4 pin to be shared in applications as an input-only general

purpose I/O pin:

0 BKGD function disabled, PTA4 enabled.

1 BKGD function enabled, PTA4 disabled.

Reserved Reserved register bit, always reads 1.

$1803 Bit 7 6 5 4 3 2 1 Bit 0

R0 COPT[2:0] LFOSEL TCLKDIV BUSCLKS[1:0]

RESET: 01110000

Figure 23. System Option Register 2 (SIMOPT2)

Table 27. SIMOPT 2 Register Field Descriptions

Field Description

Unused Unused Bit — This bit is unused and reads as a logic zero.

6:4

COPT[2:0] COP Watchdog Time Out — These control bits select the timeout period for the COP watchdog timer as given in Table 18.

These bits are set by an MCU reset to select the longest watchdog timeout period. These bits are write-once after power up.

LFOSEL

TPM1 Channel 0 Clock Source — This bit determines which signal is connected to the TPM1 Channel 0, see Section 9.

0 Select clock input driven by PTA2.

1 Select clock input driven by the LFO.

TCLKDIV

TPM1 Channel 0 CLock Source Divider — T he divider for the clock Source for TPM1 Channel 0, see Section 9.

0 Select RFM Dx clock source divided by 1.

1 Select RFM Dx clock source divided by 8.

Table 26. SIMOPT 1 Register Field Des criptions (continued)

Field Description

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5.11.4 System Power Management Status and Control 1 Register (SPMSC1)

Figure 24. System Power Management Status an d Control 1 Register (SPMSC1)

1:0

BUSCLKS

[1:0]

Bus Clock Select — Bus clock frequency selection by changing HFO FLL ratio as shown in Figure 2. The bus clock frequency

is always the HFO frequency divided by two. These bits are cleared by a reset and can be written at any time.

00 Bus Frequency = 4 MHz (HFO = 8 MHz)

01 Bus Frequency = 2 MHz (HFO = 4 MHz)

10 Bus Frequency = 1 MHz (HFO = 2 MHz)

11 Bus Frequency = 0.5 MHz (HFO = 1 MHz)

$1809 765432

1(1)

1. Bit 1 is a reserved bit that must always be written to 0.

RLVDF 0 LVDIE LVDRE(2)

2. This bit can be written only one time after reset. Additional writes are ignored.

LVDSE LVDE(2) 0BGBE

WLVDACK

Reset: 00011100

= Reserved

Table 28. SPMSC1 Register Field Descriptions

Field Description

LVDF Low-Voltage Detect Flag — Provided LVDE = 1, this read-only status bit indicates a low-voltage detect event.

LVDACK Low-Voltage Detect Acknowledge — This write-only bit is used to acknowledge low voltage detection errors (write 1 to clear

LVDF). Reads always return logic 0.

LVDIE

Low-Voltage Detect Interrupt Enable — This read/write bit enables hardware interrupt requests for LVDF.

0 Hardware interrupt disabled (use polling)

1 Request a hardware interrupt when LVDF = 1

LVDRE

Low-Voltage Detect Reset Enable — This read/write bit enables L VDF events to generate a hardware reset (provided LVDE

= 1).

0 LVDF does not generate hardware resets

1 Force an MCU reset when LVDF = 1

LVDSE

Low-Voltage Detect Stop Enable — Provided L VDE = 1, this read/write bit determines whether the low-voltage detect function

operates when the MCU is in STOP mode.

0 Low-voltage detect disabled during STOP mode

1 Low-voltage detect enabled during STOP mode

LVDE

Low-Voltage Detect Enable — This read/write bit enables low-voltage detect logic and qualifies the operation of other bits in

this register.

0 LVD logic disabled

1 LVD logic enabled

Reserved Reserved Bit — This bit is reserved should not be altered by the user. Any read returns a logical zero. Any write should be a

logical zero.

BGBE

Bandgap B uffer Enab le — The BGBE bit is used to enable an internal buffer for the bandgap voltage reference for use by the

ADC module on one of its internal channels.

0 Bandgap buffer disabled

1 Bandgap buffer enabled

Table 27. SIMOPT 2 Register Field Des criptions (continued)

Field Description

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5.11.5 System Power Management Status and Control 2 Register (SPMSC2)

This register is used to configure the STOP mode behavior of the MCU.

Figure 25. System Power Management Status an d Control 2 Register (SPMSC2)

5.11.6 System Power Management Status and Control 3 Register (SPMSC3)

Figure 26. System Power Management Status an d Control 3 Register (SPMSC3)

$180A 76543210

R000PDF00

PDC(1)

1. This bit can be written only one time after reset. Additional writes are ignored.

WPPDACK

Power-on reset: 00000000

Any other reset: 00UU0000

= Reserved U = Unaffected by reset

Table 29. SPMSC2 Register Field Descriptions

Field Description

7:5

Reserved Reserved Bits — These bits are reserved should not be altered by the user. Any read returns a logical zero.

PDF

Power Down Flag — This read-only status bit indicates the MCU has recovered from STOP1 mode.

0 MCU has not recovered from STOP1 mode

1 MCU recovered from STOP1 mode

Reserved Reserved Bit — This bit is reserved should not be altered by the user. Any read returns a logical zero.

PPDACK Partial Power Down Acknowledge — Writing a logic 1 to PPDACK clears the PDF bit.

PDC

Power Down Control — The PDC bit controls entry into the power down (STOP1) mode

0 Power down mode are disabled

1 Power down mode are enabled

Reserved Reserved Bit — This bit is reserved should not be altered by the user. Any read returns a logical zero. Any write should be a

logical zero.

$180C 76543210

RLVWF 0 LVDV LVWV 0000

WLVWACK

Power-on reset: 0(1)

1. LVWF will be set in the case when VSupply transitions below the trip point or after reset and VSupply is already below VLVW.

000 0 000

LVD reset: 0(1) 0UU 0 000

Any other reset: 0(1) 0UU 0 000

= Reserved U = Unaffected by reset

Table 30. SRTISC Register Field Descriptions

Field Description

LVWF

Low-Voltage Warning Flag — The LVWF bit indicates the low voltage warning status.

0 Low voltage warning not present

1 Low voltage warning is present or was present

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5.12 System STOP Exit Status Register (SIMSES)

The SIMSES register at $180D can be used to determine the source of an MCU wakeup from the STOP modes. The flags are

as shown in Figure 27. All of the flags are automatically cleared when the MCU goes into a STOP mode. Writes to any of these

bits are ignored.

LVWACK Low-Voltage Warning Acknowledge — The LVWF bit indicates the low voltage warning status.

Writing a logic 1 to LVWACK clears LVWF to a logic 0 if a low voltage warning is not present.

LVDV

Low-Voltage Detect Voltage Select — The LVDV bit selects the LVD trip point voltage (VLVD).

0 Low trip point selected (VLVD = VLVDL)

1 High trip point selected (VLVD = VLVDH)

LVWV

Low-Voltage Warning Voltage Select — The LVWV bit selects the LVW trip point voltage (VLVW).

0 Low trip point selected (VLVW = VLVDL)

1 High trip point selected (VLVW = VLVDH)

3:0

Reserved Reserved Bits — These bits are reserved should not be altered by the user. Any read returns a logical zero.

$180D Bit 7 6 5 4 3 2 1 Bit 0

RReserved KBF IRQF TRF PWUF LFF RFF

RESET: 00000000

= Reserved

Figure 27. SIM STOP Exit Status (SIMSES)

Table 31. SIMSES Register Field Descriptions

Field Description

7:6

Reserved Reserved Bits — These bits are reserved for Freescale firmware control. Application software shall assure these two bits are

never overwritten.

KBF

Keyboard Flag — This bit indicates that any keyboard pin caused the last exit from STOP mode.

0 Keyboard pin did not cause the last exit from STOP mode

1 Keyboard pin caused the last exit from STOP mode

IRQF

IRQ Flag — This bit indicates that IRQ pin caused the last exit from STOP mode.

0 IRQ pin did not cause the last exit from STOP mode

1 IRQ pin caused the last exit from STOP mode

TRF

Temperature Restart Flag — This bit indicates that the temperature restart module caused the last exit from STOP mode.

0 TR module did not cause the last exit from STOP mode

1 TR module caused the last exit from STOP mode

PWUF

PWU Flag — This bit indicates that the PWU module caused the last exit from STOP mode.

0 PWU module did not cause the last exit from STOP mode

1 PWU module caused the last exit from STOP mode

LFF

LFR Flag — This bit indicates that the LFR module caused the last exit from STOP mode.

0 LFR module did not cause the last exit from STOP mode

1 LFR module caused the last exit from STOP mode

RFF

RFM Flag — This bit indicates that the RFM module caused the last exit from STOP mode.

0 RFM module did not cause the last exit from STOP mode

1 RFM module caused the last exit from STOP mode

Table 30. SRTISC Register Field Descriptions (continued)

Field Description

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6 General Purpose I/O

This section explains software controls related to general purpose input/output (I/O) and pin control. The FXTH870xD has seven

general-purpose I/O pins which are comprised of a general use 5-bit port A and a 2-bit port B.

PTA[4:0] pins are shared with on-chip peripheral functions. PTB[1:0] pins are GPIO only , and are multiplexed with the LF receiver

block (see Section 6.5 for additional details regarding mutually exclusive operations).The peripheral modules have priority over

the general purpose I/O so that when a peripheral is enabled, the general purpose I/O functions associated with the shared pins

are disabled. After reset, the shared peripheral functions are disabled so that the pins are controlled by the general purpose I/O.

All of the general purpose I/O are configured as inputs (PTxDDn = 0) with pullup devices disabled (PTxPEn = 0).

To avoid extra current drain from floating input pins, the user’ s application software must configure these pins so that they do not

float (see Section 6.1).

Reading and writing of general purpose I/O is performed through the port data registers. The direction, either input or output, is

controlled through the port data direction registers. The general purpose I/O port function for an individual pin is illustrated in the

block diagram in Figure 28.

Figure 28. General Purpose I/O Block Diagram

Port Read

PTxDDn

PTxDn

Output Enable

Output Data

Input Data

Synchronizer

Data

BUSCLKS

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Figure 29. General Purpose I/O Logic

The data direction control bit (PTxDDn) determines whether the output buffer for the associated pin is enabled, and also controls

the source for port data register reads. The input buffer for the associated pin is always enabled unless the pin is enabled as an

analog function.

When a shared digital function is enabled for a pin, the output buffer is controlled by the shared function. However, the data

direction register bit still controls the source for reads of the port data register.

When a shared analog functi on is enabled for a pin, both the input and output buffers are disabled. A value of 0 is read for any

port data bit where the bit is an input (PTxDDn = 0) and the input buffer is disabled. In general, whenever a pin is shared with

both an alternate digital function and an analog functi on, the analog function has priority such that if both the digital and analog

functions are enabled, the analog function controls th e pin.

It is a good programming practice to write to the port data register before changing the direction of a port pin to become an output.

This ensures that the pin will not be driven momentarily with an old data value that happened to be in the port data register.

Table 32. Trut h Table for Pullup and Pulldow n Resistors

PTAPE[3:0]

(pull enable) PTADD[3:0]

(data direction) KBIPE[3:0]

(KBI pin enable) KBEDG[3:0]

(KBI Edge Select) Pullup Pulldown

0 0 x x disabled disabled

1 0 0 x enabled disabled

x 1 x x disabled disabled

1 0 1 0 enabled disabled

1 0 1 1 disabled enabled

PTBPE[1:0]

(pull enable) PTBDD[1:0]

(data direction)

0 0 x x disabled x

1 0 x x enabled x

x 1 x x disabled x

PTxPEn

KBEDEy

KBIPGy VDD

PTxDn

RPU

RPD

PTxDDn

Write

PTxDn

Read

PTxPEn

KBEDGy

KBIPEy

KBI interrupt

KBACK KBMOD

Port pin

PTA[3:0]

only

PTA[3:0]

only

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An internal pullup device can be enabled for each port pin by settin g the corresp onding bit in one of the pullup enable registers

(PTxPEn). The pullup device is disabled if the pin is configured as an output by the general purpose I/O control logic or any shared

peripheral function regardless of the state of the corresponding pullup enable register bit. The pullup device is also disabled if the

pin is controlled by an analog function.

6.1 Unused Pin Configuration

Any general purpose I/O pins which are not used in the application must be properly configured to avoid a floating input that could

cause excessive supply current, IDD.

When the device comes out of the reset state the Freescale supplied firmware will not configure any of the general purpose I/O

pins.

Recommended configuration methods are:

1. Configure the general purpose I/O pin as an input (PTxDDn = 0) with the pin connected to the VDD source; use a

pullup resistor of 10-51 k to assure sufficient noise immunity.

2. Configure the general purpose I/O pin as an input (PTxDDn = 0) with the internal pullup activated (PTxPEn = 1) and

leave the pin disconnected.

3. Configure the general purpose I/O pin as an output (PTxDDn = 1) and drive the pin low (PTxDn = 0) and leave the pin

disconnected.

In cases where GPIOs are directly connected to A VDD, VDD, AVSS, VSS or RVSS, user application should configure the GPIO as

an input with the internal pull-up disabled, in order to prevent software code faults from causing excessive supply current states

should these pins become outputs.

6.2 Pin Behavior in STOP Modes

Pin behavior following execution of a STOP instruction depends on the STOP mode that is entered. An explanation of pin

behavior for the various STOP modes follows:

• In STOP1 mode, all internal registers including general purpose I/O control and data registers are powered off. Each of the

pins assumes its default reset state (input buffer , output buffer and internal pullup disabled). Upon exit from STOP1, all pins

must be reconfigured the same as if the MCU had been reset.

• In STOP4 mode, all pin states are maintained because internal logic stays powered up. Upon recovery , all pin functions are

the same as before entering STOP4.

6.3 General Purpose I/O Registers

This section provides information about the registers associated with the general purpose I/O ports and pin control functions.

These general purpose I/O registers are located in page zero of the memory map and the pin control registers are located in the

high page register section of memory.

6.4 Port A Registers

Port A general purpose I/O function is controlled by the registers described in this section.

$0000 Bit 7 654321Bit 0

RPTAD[4:0]

Reset: 00000000

= Reserved

Figure 30. Port A Data Register (PTAD)

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Table 33. Port A Data Register Field Descriptions

Field Description

4:0

PTAD

[4:0]

Port A Data Register Bit — For port A pins that are inputs, reads return the logic level on the pin. For port A pins that are

configured as outputs, reads return the last value written to this register.

Writes are latched into all bits of this register. For port A pins that are configur ed as outputs, the logic level is driven out the

corresponding MCU pin.

Reset forces PTAD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins

as high-impedance inputs with pullups disabled.

$0001 Bit 7 654321Bit 0

RPTAPE[3:0]

Reset: 00000000

= Reserved

Figure 31. Internal Pullup Enable for Port A Register (PTAPE)

Table 34. Port A Register Pullup Enable Field Descriptions

Field Description

3:0

PTAPE

[3:0]

Internal Pullup Enable for Port A Bit n — Each of these control bits determines if the internal pullup device is enabled for the

associated PTA pin. For port A pins that are configured as outputs, these bits have no effect and the internal pullup devices are

disabled.

0 Internal pullup device disabled for port A bit n.

1 Internal pullup device enabled for port A bit n.

$0003 Bit 7 654321Bit 0

RPTADD[3:0]

Reset: 00000000

= Reserved

Figure 32. Data Direction for Port A Register (PTADD)

Table 35. Port A Data Di rection Field Descriptions

Field Description

3:0

PTADD

[3:0]

Data Direction for Port A Bit n — These read/write bits control the direction of port A pins and what is read for PTADD reads.

0 Input (output driver disabled) and reads return the pin value.

1 Output driver enabled for port A bit n and PTADD reads return the contents of PTADDn. PTA4 is input-only, therefore bit 4 will

always be 0.

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6.5 Port B Registers

Port B PTB[1:0] functions are multiplexed with the LF receiver block such that the port B GPIOs become high impedance when

the LF block has been enabled. When the LF block is disabled , port B pins operate as described here.

$0004 Bit 7 654321Bit 0

RPTBD[1:0]

Reset: 00000000

= Reserved

Figure 33. Port B Data Register (PTBD)

Table 36. Port B Data Register Field Descriptions

Field Description

1:0

PTBD

[1:0]

Port B Data Register Bit n — For port B pins that are inputs, reads return the logic level on the pin. For port B pins that are

configured as outputs, reads return the last value written to this register.

Writes are latched into all bits of this register. For port B pins that are configur ed as outputs, the logic level is driven out the

corresponding MCU pin.

Reset forces PTBD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins

as high-impedance inputs with pullups disabled.

$0005 Bit 7 654321Bit 0

RPTBPE[1:0]

Reset: 00000000

= Reserved

Figure 34. Internal Pullup Enable for Port B Register (PTBPE)

Table 37. Port B Register Pullup Enable Field Descriptions

Field Description

1:0

PTBPE

[1:0]

Internal Pullup Enable for Port B Bit n — Each of these control bits determines if the internal pullup device is enabled for the

associated PTB pin. For port B pins that are configured as output s, these bit s have no ef fect and the internal pullup devices are

disabled.

0 Internal pullup device disabled for port B bit n.

1 Internal pullup device enabled for port B bit n.

$0007 Bit 7 654321Bit 0

RPTBDD[1:0]

Reset: 00000000

= Reserved

Figure 35. Data Direction for Port B Register (PTBDD)

Table 38. Port B Data Di rection Field Descriptions

Field Description

1:0

PTBDD

[1:0]

Data Direction for Port B Bit n — These read/write bits control the direction of port B pins and what is read for PTBDD reads.

0 Input (output driver disabled) and reads return the pin value.

1 Output driver enabled for port B bit n and PTBDD reads return the contents of PTBDDn.

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7 Keyboard Interrupt

The FXTH870xD has a KBI module with general purpose I/O pins.

7.1 Features

The KBI features include:

• Up to four keyboard interrupt pins with individual pin enable bits.

• Each keyboard interrupt pin is programmable as falling edge (or rising edge) only , or both falling edge and low level (or both

rising edge and high level) interrupt sensitivity.

• One software enabled keyboard interrupt.

• Exit from low-power modes.

7.2 Modes of Operation

This section defines the KBI operation in W AIT, STOP, and BACKGROUND DEBUG modes.

7.2.1 KBI in STOP Modes

The KBI operates asynchronously in STOP4 mode if enabled before executing the STOP instruction. Therefore, an enabled KBI

pin (KBPE[3:0]) can be used to bring the MCU out of STOP4 mode if the KBI interrupt is enabled (KBIE = 1).

During STOP1 mode, the KBI is disabled. In some systems, the pins associated with the KBI may be sources of wakeup from

STOP1, see the STOP modes section in the Section 3. Upon wakeup from STOP1 mode, the KBI module will be in the reset

state.

7.2.2 KBI in ACTIVE BACKGROUND mode

When the microcontroller is in ACTIVE BACKGROUND mode, the KBI will continue to operate normall y.

7.3 Block Diagram

The block diagram for the keyboard interrupt module is shown Figure 36.

Figure 36. KBI Block Diagram

7.4 External Signal Description

The KBI input pins can be used to detect either falling edges, or both falling edge and low level interrupt requests. The KBI input

pins can also be used to detect either rising edges, or both rising edge and high level interrupt requests.

The signal properties of KBI are shown in Table 39.

Table 39. Signal Properties

Signal Function I/O

KBIPn Keyboard interrupt pins I

CLR

KBMOD

KBIE

KEYBOARD

INTERRUPT FF

KBACK

RESET

SYNCHRONIZER

KBF

STOP BYPASS

STOP

BUSCLK

KBIPEn

KBEDGn

KBIPE0

KBEDG0

KBIP0

KBIPn

KBI

INTERRUP

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7.5 Register Definitions

The KBI includes three registers:

• An 4-bit pin status and control register.

• An 4-bit pin enable register.

• An 4-bit edge select register.

7.5.1 KBI Status and Control Register (KBISC)

KBISC contains the status flag and control bits, which are used to configure the KBI.

7.5.2 KBI Pin Enable Register (KBIPE)

KBIPE contains the pin enable control bits.

$000C 7 6 5 4 3 2 1 0

R0000KBF0

KBIE KBMOD

WKBACK

Reset: 00000000

= Reserved

Figure 37. KBI Status and Control Register

Table 40. KBISC Register Field Descriptions

Field Description

7:4 Unused register bits, always read 0.

KBF

Keyboard Interrupt Flag — KBF indicates when a keyboard interrupt is detected. Writes have no effect on KBF.

0 No keyboard interrupt detected.

1 Keyboard interrupt detected.

KBACK Keyboard Acknowledge — Writing a 1 to KBACK is part of the flag clearing mechanism. KBACK always reads as 0.

KBIE

Keyboard Interrupt Enable — KBIE determines whether a keyboard interrupt is requested.

0 Keyboard interrupt request not enabled.

1 Keyboard interrupt request enabled.

KBMOD

Keyboard Detection Mode — KBMOD (along with the KBEDG bits) controls the detection mode of the keyboard interrupt pins.

0 Keyboard detects edges only.

1 Keyboard detects both edges and levels.

$000D 7 6 5 4 3 2 1 0

RKBIPE3 KBIPE2 KBIPE1 KBIPE0

Reset: 00000000

Figure 38. KBI Pin Enable Register

Table 41. KBIPE Register Field Descriptions

Field Description

3:0

KBIPEn

Keyboard Pin Enables — Each of the KBIPEn bits enable the corresponding keyboard interrupt pin.

0 Pin not enabled as keyboard interrupt.

1 Pin enabled as keyboard interrupt.

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7.5.3 KBI Edge Select Register (KBIES)

KBIES contains the edge select control bits.

7.6 Functional Description

This on-chip peripheral module is called a keyboard interrupt (KBI) module because originally it was designed to simplify the

connection and use of row-column matrices of keyboard switches. However, these inputs are also useful as extra external

interrupt inputs and as an external means of waking the MCU from STOP or WAIT low-power modes.

The KBI module allows up to eight pins to act as additional interrupt sources. Writing to the KBIPE[3:0] bits in the keyboard

interrupt pin enable register (KBIPE) independently enables or disables each KBI pin. Each KBI pin can be configured as edge

sensitive or edge and level sensitive based on the KBMOD bit in the keyboard interrupt status and control register (KBISC). Edge

sensitive can be software programmed to be either falling or rising; the level can be either low or high. The polarity of the edge

or edge and level sensitivity is selected using the KBEDG[3:0] bits in the keyboard interrupt edge select register (KBIES).

Synchronous logic is used to detect edges. Prior to detecting an edge, enabled keyboard inputs must be at the reset logic level.

A falling edge is detected when an enabled keyboard input signal is seen as a logic 1 (the reset level) during one bus cycle and

then a logic 0 (the asserted level) during the next cycle. A rising edge is detected when the input signal is seen as a logic 0 during

one bus cycle and then a logic 1 during the next cycle.

7.6.1 Edge Only Sensitivity

A valid edge on an enabled KBI pin will set KBF in KBISC. If KBIE in KBISC is set, an interrupt request will be presented to the

CPU. Clearing of KBF is accomplished by writing a 1 to KBACK in KBISC.

7.6.2 Edge and Level Sensitivity

A valid edge or level on an enabled KBI pin will set KBF in KBISC. If KBIE in KBISC is set, an interrupt request will be presented

to the CPU. Clearing of KBF is accomplished by writing a 1 to KBACK in KBISC provided all enabled keyboard inputs are at their

reset levels. KBF will remain set if any enabled KBI pin is asserted while attempting to clear by writing a 1 to KBACK.

7.6.3 KBI Pullup/Pulldown Resistors

The KBI pins can be configured to use an inte rnal pullup/pulldown resistor using the associated I/O port pullup enable register.

If an internal resistor is enabled, the KBIES reg ister is used to select whether the resistor is a pullup (KBEDG[3:0] = 1) or a

pulldown (KBEDG[3:0] = 0).

7.6.4 KBI Initialization

When a keyboard interrupt pin is first enabled it is possible to get a false keyboard interrupt flag. To prevent a fa lse interrupt

request during keyboard initia lization, the user should do the following:

1. Mask keyboard interrupts by clearing KBIE in KBISC.

2. Enable the KBI polarity by setting the appropriate KBEDGn bits in KBIES.

3. If using internal pullup/pulldown device, configure the associated pullup enable bits in PTAPE[3:0].

4. Enable the KBI pins by setting the appropriate KBIPE[3:0] bits in KBIPE.

5. Write to KBACK in KBISC to clear any false interrupts.

6. Set KBIE in KBISC to enable interrupts.

$000E 7 6 5 4 3 2 1 0

RKBEDG7 KBEDG6 KBEDG5 KBEDG4 KBEDG3 KBEDG2 KBEDG1 KBEDG0

Reset: 00000000

Figure 39. KBI Edge Select Register

Table 42. KBIES Register Field Descriptions

Field Description

7:0

KBEDGn

Keyboard Edge Selects — Each of the KBEDGn bits selects the falling edge/low level or rising edge/high level function of the

corresponding pin).

0 Falling edge/low level.

1 Rising edge/high level.

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8 Central Processing Unit

8.1 Introduction

This section provides summary information about the registers, addressing modes, and instruction set of the CPU of the HCS08

Family. For a more detailed discussion, refer to the HCS08 Family Reference Manual, vol ume 1, Freescale Semiconductor

document order number HCS08RMV1/D.

The HCS08 CPU is fully source- and object-code-compatible with the M68HC08 CPU. Several instructions an d enhanced

addressing modes were added to improve C compiler efficiency and to support a new BACKGROUND DEBUG system which

replaces the monitor mode of earlier M68HC08 microcon trollers (MCU).

8.2 Features

Features of the HCS08 CPU include:

• Object code fully upward-compatible with M68HC05 and M68HC08 Families

• All registers and memory are mapped to a single 64-Kbyte address space

• 16-bit stack pointer (any size stack anywhere in 64-Kbyte address space)

• 16-bit index register (H:X) with powerful indexed addressing modes

• 8-bit accumulator (A)

• Many instructions treat X as a second general-purpose 8-bit register

• Seven addressing modes:

— Inherent — Operands in internal registers

— Relative — 8-bit signed offset to branch destination

— Immediate — Operand in next object code byte(s)

— Direct — Operand in memory at 0x0000–0x00FF

— Extended — Operand anywhere in 64-Kbyte address space

— Indexed relative to H:X — Five submodes including auto-increment

— Indexed relative to SP — Improves C efficiency dramatically

• Memory-to-memory data move instructions with four address mode combinations

• Overflow, half-carry, negative, zero, and carry condition codes support conditional branching on the results of signed,

unsigned, and binary-coded decimal (BCD) operations

• Efficient bit manipulation instructions

• Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divid e instru ctions

• STOP and WAIT instructions to invoke low-power operating modes

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8.3 Programmer’s Model and CPU Registers

Figure 40 shows the five CPU registers. CPU registers are not part of the memory map.

Figure 40. CPU Registers

8.3.1 Accumulator (A)

The A accumulator is a general-purpose 8-bit register. One operand input to the arithmetic logic unit (ALU) is connected to the

accumulator and the ALU results are often stored into the A accumulator after arithmetic and logical operations. The accumulator

can be loaded from memory using various addressing modes to specify the address where the loaded data comes from, or the

contents of A can be stored to memory using various addressing modes to specify the address where data from A will be stored.

Reset has no effect on the contents of the A accumulator.

8.3.2 Index Register (H:X)

This 16-bit register is actually two separate 8-bit registers (H and X), which often work together as a 16-bit address pointer where

H holds the upper byte of an address and X holds the lower byte of the address. All indexed addressing mode instructions use

the full 16-bit value in H:X as an index reference pointer; however, for compatibility with the earlier M68HC05 Family, some

instructions operate only on the low-order 8-bit half (X).

Many instructions treat X as a second general-purpose 8-bit register that can be used to hold 8-bit data values. X can be cleared,

incremented, decremented, comple mented, negated, shifted, or rotated. Transfer instructions allow data to be transferred from

A or transferred to A where arithmetic and logical operations can then be performed.

For compatibility with the earlier M68HC05 Family, H is forced to 0x00 during reset. Reset has no effect on the contents of X.

8.3.3 Stack Pointer (SP)

This 16-bit address pointer register points at the next available location on the automatic last-in-first-out (LIFO) stack. The stack

may be located anywhere in the 64-Kbyte address space that has RAM and can be any size up to the amount of available RAM.

The stack is used to automatically save the return address for subroutine calls, the retu rn address and CPU registers during

interrupts, and for local variables. The AIS (add immediate to stack pointer) instruction adds an 8-bit signed immediate value to

SP. This is most often used to allocate or deallocate space for local variables on the stack.

SP is forced to 0x00FF at reset for compatibility with the earlier M68HC05 Family. HCS08 programs normally change the value

in SP to the address of the last location (highest address) in on-chip RAM during reset initialization to free up direct page RAM

(from the end of the on-chip registers to 0x00FF).

The RSP (reset stack pointer) instruction was included for compatibility with the M68HC05 Family and is seldom used in new

HCS08 programs because it only affects the low-order half of the stack pointer.

CONDITION CODE REGISTER

CARRY

ZERO

NEGATIVE

INTERRUPT MASK

HALF-CARRY (FROM BIT 3)

TWO’S COMPLEMENT OVERFLOW

H X

ACCUMULATOR A

INDEX REGISTER (LOW)INDEX REGISTER (HIGH)

STACK POINTER

PROGRAM COUNTER

16-BIT INDEX REGISTER H:X

CCR

CV11HINZ

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8.3.4 Program Counter (PC)

The program counter is a 16-bit register that contains the address of the next instruction or operand to be fetched.

During normal program execution, the program counte r automatically increments to the next sequential memo ry location every

time an instruction or operand is fetched. Jump, branch, interrupt, and return operations load the program counter with an

address other than that of the next sequential location. This is called a change-of-flow.

During reset, the program counter is loaded with the reset vector that is located at 0xFFFE and 0xFFFF. The vector stored there

is the address of the first instruction that will be executed after exiting the reset state.

8.3.5 Condition Code Register (CCR)

The 8-bit condition code register contains the interrupt mask (I) and five flags that indicate the results of the instruction just

executed. Bits 6 and 5 are set permanently to 1. The fo llowing paragraphs describe the functions of the condition code bits in

general terms. For a more detailed explanation of how each instruction sets the CCR bits, refer to the HCS08 Family Reference

Manual, volume 1, Freescale Semiconductor document order number HCS08RMv1.

Figure 41. Condition Cod e Reg is te r

Table 43. CCR Register Field Descriptions

Field Description

Two’s Complement Overflow Flag — The CPU sets the overflow flag when a two’s complement overflow occurs. The signed

branch instructions BGT, BGE, BLE, and BLT use the overflow flag.

0 No overflow

1Overflow

Half-Carry Flag — The CPU sets the half-carry flag when a carry occurs between accumulator bits 3 and 4 during an add-without-

carry (ADD) or add-with-carry (ADC) operation. The half-carry flag is required for binary-coded decimal (BCD) arithmetic

operations. The DAA instruction uses the states of the H and C condition code bits to automatically add a correction value to the

result from a previous ADD or ADC on BCD operands to correct the result to a valid BCD value.

0 No carry between bits 3 and 4

1 Carry between bits 3 and 4

Interrupt Mask Bit — When the interrupt mask is set, all maskable CPU interrupts are disabled. CPU interrupts are enabled when

the interrupt mask is cleared. When a CPU interrupt occurs, the interrupt mask is set automatically after the CPU registers are

saved on the stack, but before the first instruction of the interrupt service routine is executed.

Interrupts are not recognized at the instruction boundary after any instruction that clears I (CLI or T AP). This ensures that the next

instruction after a CLI or TAP will always be executed without the possibility of an intervening interrupt, provided I was set.

0 Interrupts enabled

1 Interrupts disabled

Negati ve Flag — The CPU sets the negative flag when an arithmetic operation, logic operation, or data manipulation produces

a negative result, setting bit 7 of the result. Simply loading or storing an 8-bit or 16-bit value causes N to be set if the most

significant bit of the loaded or stored value was 1.

0 Non-negative result

1 Negative result

Zero Flag — The CPU sets the zero flag when an arithmetic operation, logic operation, or data manipulation produces a result

of 0x00 or 0x0000. Simply loading or storing an 8-bit or 16-bit value causes Z to be set if the loaded or stored value was all 0s.

0 Non-zero result

1 Zero result

CONDITION CODE REGISTER

CARRY

ZERO

NEGATIVE

INTERRUPT MASK

HALF-CARRY (FROM BIT 3)

TWO’S COMPLEMENT OVERFLOW

CCR

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8.4 Addressing Modes

Addressing modes define the way the CPU accesses operands and data. In the HCS08, all memory , status and control registers,

and input/output (I/O) ports share a single 64-Kbyte linear address space so a 16-bit binary address can uniquely identify any

memory location. This arrangement means that the same instructions that access variables i n RAM can also be u sed to acces s

I/O and control registers or nonvolatile program space.

Some instructions use more than one addressing mode. For instance, move instructions use one addressing mode to specify the

source operand and a second addressing mode to specify the destination address. Instructions such as BRCLR, BRSET, CBEQ,

and DBNZ use one addressing mode to specify the location of an operand for a test and then use relative addressing mode to

specify the branch destination address when the tested condition is true. For BRCLR, BRSET, CBEQ, and DBNZ, the addressing

mode listed in the instructio n set tables is the addressing mode needed to access the operand to be tested, and relative

addressing mode is implied for the branch destination.

8.4.1 Inherent Addressing Mode (INH)

In this addressing mode, operands needed to complete the instruction (if any) are located within CPU registers so the CPU does

not need to access memory to get any operands.

8.4.2 Relative Addressing Mode (REL)

Relative addressing mode is used to specify the destination location for branch instructions. A signed 8-bit offset value is located

in the memory location immediately following the opcode. During execution, if the branch condition is true, the signed offset is

sign-extended to a 16-bit value and is added to the current contents of the program counter , which causes program execution to

continue at the branch destination address.

8.4.3 Immediate Addressing Mode (IMM)

In immediate addressing mode, the operand needed to complete the instruction is included in the object code immediately

following the instruction opcode in memory. In the case of a 16-bit immediate operand, the high-order byte is located in the next

memory location after the opcode, and the low-order byte is located in the next memory location after that.

8.4.4 Direct Addressing Mode (DIR)

In direct addressing mode, the instruction includes the low-order eight bits of an address in the direct page (0x0000–0x00FF).

During execution a 16-bit address is formed by concatenating an implied 0x00 for the high-order half of the address and the direct

address from the instruction to get the 16-bit address where the desired operand is loca ted. This is faster and more memory

efficient than specifying a complete 16-bit address for the operand.

8.4.5 Extended Addressing Mode (EXT)

In extended addressing mode, the full 16-bit address of the operand is located in the next two bytes of program memory after the

opcode (high byte first).

8.4.6 Indexed Addressing Mode

Indexed addressing mode has seven variations including five that use the 16-bit H:X index register pair and two that use the stack

pointer as the base reference.

8.4.6.1 Indexed, No Offset (IX)

This variation of indexed addressing uses the 16-bit value in the H:X index register pair as the address of the operand needed

to complete the instruction.

8.4.6.2 Indexed, No Offset with Post Increment (IX+)

This variation of indexed addressing uses the 16-bit value in the H:X index register pair as the address of the operand needed

to complete the instruction. The index register pair is then incremented (H:X = H:X + 0x0001) after the operand has been fetched.

This addressing mode is only used for MOV and CBEQ instructions.

Carry/Borrow Flag — The CPU sets the carry/borrow flag when an addition operation produces a carry out of bit 7 of the

accumulator or when a subtraction operation requires a borrow . Some instructions — such as bit test and branch, shift, and rotate

— also clear or set the carry/borrow flag.

0 No carry out of bit 7

1 Carry out of bit 7

Table 43. CCR Register Field Descriptions (continued)

Field Description

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8.4.6.3 Indexed, 8-Bit Offset (IX1)

This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus an unsigned 8-bit offset included in

the instruction as the addres s of the operand needed to complete the instruction.

8.4.6.4 Indexed, 8-Bit Offset with Post Increment (IX1+)

This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus an unsigned 8-bit offset included in

the instruction as the address of the operand needed to complete the instruction. The index register pair is then incremented

(H:X = H:X + 0x0001) after the operand has been fetched. This addressing mode is used only for the CBEQ instruction.

8.4.6.5 Indexed, 16-Bit Offset (IX2)

This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus a 16-bit offset included in the

instruction as the address of the opera nd needed to complete the instruction.

8.4.6.6 SP-Relative, 8-Bit Offset (SP1)

This variation of indexed addressing uses the 16-bit value in the stack pointer (SP) plus an unsigned 8-bit offset included in the

instruction as the address of the operand needed to complete the instruction.

8.4.6.7 SP-Relative, 16-Bit Offset (SP2)

This variation of indexed addressing uses the 16-bit value in the stack pointer (SP) plus a 16-bit offset included in the instruction

as the address of the operand needed to complete the instruction.

8.5 Special Operations

The CPU performs a few special operations that are similar to instructions but do not have opcodes like other CPU instructions.

In addition, a few instructions such as STOP and WAIT directly affect other MCU circuitry. This section provides additional

information about these operations.

8.5.1 Reset Sequence

Reset can be caused by a power-on-reset (POR) event, internal conditions such as the COP (computer operating properly)

watchdog, or by assertion of an external active-low reset pin. When a reset event occurs, the CPU immediately stops whatever

it is doing (the MCU does not wait for an instruction boundary before responding to a reset event). For a more detailed discussion

about how the MCU recognizes resets and determines th e source, refer to the Section 5.

The reset event is considered concluded when the sequence to determine whether the reset came from an internal source is

done and when the reset pin is no longer asserted. At the conclusion of a reset event, the CPU performs a 6-cycle sequence to

fetch the reset vector from 0xFFFE and 0xFFFF and to fill the instruction queue in preparation for execution of the first program

instruction.

8.5.2 Interrupt Sequence

When an interrupt is requested, the CPU completes the current instruction before responding to the interrupt. At this point, the

program counter is pointing at the start of the next instruction, which is where the CPU should return after servicing the interrupt.

The CPU responds to an interrupt by performing the same sequence of operations as for a software interrupt (SWI) instruction,

except the address used for the vector fetch is determined by the highest priori ty interrupt that is pending when the interrupt

sequence started.

The CPU sequence for an interrupt is:

1. Store the contents of PCL, PCH, X, A, and CCR on the stack, in that order.

2. Set the I bit in the CCR.

3. Fetch the high-order half of the interrupt vector.

4. Fetch the low-order half of the interrupt vector.

5. Delay for one free bus cycle.

6. Fetch three bytes of program information starting at the address indicated by the interrupt vector to fill the instruction

queue in preparation for execution of the first instruction in the interrupt service routine.

After the CCR contents are pushed onto the stack, the I bit in the CCR is set to prevent other interrupts while in the interrupt

service routine. Although it is possible to clear the I bit with an instruction in the interrupt service routine, this would allow nesting

of interrupts (which is not recommended because it leads to programs that are difficult to debug and maintain).

For compatibility with the earlier M68HC05 MCUs, the high-order half of the H:X index register pair (H) is not saved on the stack

as part of the interrupt sequence. The user must use a PSHH instruction at the beginning of the service routine to save H and

then use a PULH instruction just before the RTI that ends the interrupt service routine. It is not necessary to save H if you are

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certai n tha t the interrupt service rout in e does not use an y in structions or auto-increment addressing modes that might change

the value of H.

The software interrupt (SWI) instruction is like a hardware interrupt except that it is not masked by the global I bit in the CCR and

it is associated with an instruction opcode within th e program so it is not asynchronous to program execution.

8.5.3 WAIT Mode Operation

The WAIT instruction enables interrupts by clearing the I bit in the CCR. It then halts the clocks to the CPU to reduce overall

power consumption while the CPU is waiting for the interrupt or reset event that will wake the CPU from WAIT mode. When an

interrupt or reset event occurs, the CPU clocks will resume and the interrupt or reset event will be processed normally.

If a serial BACKGROUND command is issued to the MCU through the BACKGROUND DEBUG interface while the CPU is in

W AIT mode, CPU clocks will resume and the CPU will enter ACTIVE BACKGROUND mode where other serial BACKGROUND

commands can be processed. This ensures that a host development system can still gain access to a target MCU even if it is in

WAIT mode.

8.5.4 STOP Mode Operation

Usually, all system clocks, including the crystal oscillator (when used), are halted during STOP mode to minimize power

consumption. In such systems, external circuitry is needed to control the time spent in STOP mode and to issue a signal to

wakeup the target MCU when it is time to resume processing. Unlike the earlier M68HC05 and M68HC08 MCUs, the HCS08 can

be configured to keep a minimum set of clocks running in STOP mode. This optionally allows an internal periodic signal to wake

the target MCU from STOP mode.

When a host debug system is connected to the BACKGROUND DEBUG pin (BKGD) and the ENBDM control bit has been set

by a serial command through the BACKGROUND interface (or because the MCU was reset into ACTIVE BACKGROUND mode),

the oscillator is forced to remain active when the MCU enters STOP mode. In this case, if a serial BACKGROUND command is

issued to the MCU through the BACKGROUND DEBUG interface while the CPU is in STOP mode, CPU clocks will resume and

the CPU will enter ACTIVE BACKGROUND mode where other serial BACKGROUND commands can be processed. This

ensures that a host development system can still gain access to a target MCU even if it is in STOP mode.

Recovery from STOP mode depends on the particular HCS08 and whether the oscillator was stopped in STOP mode. Refer to

the Section 3 for more details.

8.5.5 BGND Instruction

The BGND instruction is new to the HCS08 compared to the M68HC08. BGND would not be used in normal user programs

because it forces the CPU to stop processing user instructions and enter the ACTIVE BACKGROUND mode. The only way to

resume execution of the user program is through reset or by a host debug system issuing a GO, TRACE1, or TAGGO serial

command through the BACKGROUND DEBUG interface .

Software-based breakpoints can be set by replacing an opcode at the desired breakpoint address with the BGND opcode. When

the program reaches this breakpoint address, the CPU is forced to ACTIVE BACKGROUND mode ra ther than continuing the

user program.

8.6 HCS08 Instruction Set Summary

Instruction Set Summary Nomenclature

The nomenclature listed here is used in the instruction descriptions in Table 44.

Operators ( ) = Contents of register or memory location shown inside parentheses

= Is loaded with (read: “gets”)

& = Boolean AND

| = Boolean OR

= Boolean exclusive-OR

= Multiply

= Divide

: = Concatenate

+=Add

– = Negate (two’s complement)

CPU registers

A = Accumulator

CCR = Condition code register

H = Index register, higher order (most significant) 8 bits

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X = Index register, lower order (least significant) 8 bits

PC = Program counter

PCH = Program counter, higher order (most significant) 8 bits

PCL = Program counter, lower order (least significant) 8 bits

SP = Stack pointer

Memory and addressing

M = A memory location or absolute data, depending on addressing mode

M:M + 0x0001 = A 16-bit value in two consecutive memory locations. The higher-order (most significant) 8 bits are

located at the address of M, and the lower-order (least significant) 8 bits are located at the next higher

sequential address.

Condition code register (CCR) bits

V = Two’s complement overflow indicator, bit 7

H = Half carry, bit 4

I = Interrupt mask, bit 3

N = Negative indicator, bit 2

Z = Zero indicator, bit 1

C = Carry/borrow, bit 0 (carry out of bit 7)

CCR activity notation

– = Bit not affected

0 = Bit forced to 0

1 = Bit forced to 1

Þ= Bit set or cleared according to results of operation

U = Undefined after the operation

Machine coding notation

dd = Low -order 8 bits of a direct address 0x0000–0x00FF (high byte assumed to be 0x00)

ee = Upper 8 bits of 16-bit offset

ff = Lower 8 bits of 16-bit offset or 8-bit offset

ii = One byte of immediate data

jj = High-order byte of a 16-bit immediate data value

kk = Low-order byte of a 16 -bit immediate data value

hh = High-order byte of 16-bit exte nded address

ll = Low-order byte of 16-bit extended address

rr = Relative offset

Source form

Everything in the source forms columns, except expressions in italic characters, is literal information that must appear in the

assembly source file exactly as shown. The initial 3- to 5-letter mnemonic is always a literal expression. All commas, pound signs

(#), parentheses, and plus signs (+) are literal characters.

n— Any label or expression that eval uates to a single integer in the range 0–7

opr8i — Any label or expression that evaluates to an 8-bit immediate value

opr16i — Any label or expression that evaluates to a 16-bit immediate value

opr8a — Any label or expression that evaluates to an 8-bit value. The instruction treats this 8-bit value as

the low order 8 bits of an address in the direct page of the 64-Kbyte address space (0x00xx).

opr16a — Any label or expression that evaluates to a 16-bit value. The instruction treats this value as an

address in the 64-Kbyte address space.

oprx8 — Any label or expression that evaluates to an unsigned 8-bit value, used for indexed addressing

oprx16 — Any label or expression that eval uates to a 16-bit value. Because the HCS08 has a 16-bit

address bus, this can be either a signed or an unsigned value.

rel — Any label or expression that refers to an address that is within –128 to +127 locations from the

next address after the last byte of object code for the current instruction. The assembler will

calculate the 8-bit signed offset and include it in the object code for this instruction.

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Address modes

INH = Inhere nt (no operands)

IMM = 8-bit or 16-bit immediate

DIR = 8-bit direct

EXT = 16-bit extended

IX = 16-bit indexed no offset

IX+ = 16-bit indexed no offset, post increment (CBEQ and MOV only)

IX1 = 16-bit indexed with 8-bit offset from H:X

IX1+ = 16-bi t i nd e x e d wi t h 8-b i t offset, post increm ent

(CBEQ only)

IX2 = 16-bit indexed with 16-bit offset from H:X

REL = 8-bit relative offset

SP1 = Stack pointer with 8-bit offset

SP2 = Stack pointer with 16-bit offset

Table 44. HCS08 Instruction Set Summary (Sheet 1 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

ADC #opr8i

ADC opr8a

ADC opr16a

ADC oprx16,X

ADC oprx8,X

ADC ,X

ADC oprx16,SP

ADC oprx8,SP

Add with Carry A  (A) + (M) + (C) ÞÞ–ÞÞÞ

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED9

9EE9

hh ll

ee ff

ADD #opr8i

ADD opr8a

ADD opr16a

ADD oprx16,X

ADD oprx8,X

ADD ,X

ADD oprx16,SP

ADD oprx8,SP

Add without Carry A  (A) + (M) ÞÞ–ÞÞÞ

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9EDB

9EEB

hh ll

ee ff

AIS #opr8i Add Immediate Value

(Signed) to Stack Pointer SP  (SP) + (M)

M is sign extended to a 16-bit value ––––––IMM A7ii 2

AIX #opr8i Add Immediate Value

(Signed) to Index

H:X  (H:X) + (M)

M is sign extended to a 16-bit value ––––––IMM AFii 2

AND #opr8i

AND opr8a

AND opr16a

AND oprx16,X

AND oprx8,X

AND ,X

AND oprx16,SP

AND oprx8,SP

Logical AND A  (A) & (M) 0 – – ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED4

9EE4

hh ll

ee ff

ASL opr8a

ASLA

ASLX

ASL oprx8,X

ASL ,X

ASL oprx8,SP

Arithmetic Shift Left

(Same as LSL) Þ––ÞÞÞ

DIR

INH

IX1

SP1

9E68

Cb0

b7 0

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ASR opr8a

ASRA

ASRX

ASR oprx8,X

ASR ,X

ASR oprx8,SP

Arithmetic Shift Right Þ––ÞÞÞ

DIR

INH

IX1

SP1

9E67

BCC rel Branch if Carry Bit Clear Branch if (C) = 0 – – – – – – REL 24 rr 3

BCLR n,opr8a Clear Bit n in Memory Mn  0 ––––––

DIR (b0)

DIR (b1)

DIR (b2)

DIR (b3)

DIR (b4)

DIR (b5)

DIR (b6)

DIR (b7)

BCS rel Branch if Carry Bit Set

(Same as BLO) Branch if (C) = 1 – – – – – – REL 25 rr 3

BEQ rel Branch if Equal Branch if (Z) = 1 – – – – – – REL 27 rr 3

BGE rel Branch if Greater Than or

Equal To

(Signed Operands) Branch if (N V ––––––REL 90rr 3

BGND Enter ACTIVE BACK-

GROUND if ENBDM = 1

Waits For and Processes BDM

Commands Until GO, TRACE1, or

TAGGO ––––––INH 82 5+

BGT rel Branch if Greater Than

(Signed Operands) Branch if (Z)| (N V ––––––REL 92rr 3

BHCC rel Branch if Half Carry Bit

Clear Branch if (H) = 0 – – – – – – REL 28 rr 3

BHCS rel Branch if Half Carry Bit

Set Branch if (H) = 1 – – – – – – REL 29 rr 3

BHI rel Branch if Higher Branch if (C) | (Z) = 0 – – – – – – REL 22 rr 3

BHS rel Branch if Higher or Same

(Same as BCC) Branch if (C) = 0 – – – – – – REL 24 rr 3

BIH rel Branch if IRQ Pin High Branch if IRQ pin = 1 – – – – – – REL 2F rr 3

BIL rel Branch if IRQ Pin Low Branch if IRQ pin = 0 – – – – – – REL 2E rr 3

BIT #opr8i

BIT opr8a

BIT opr16a

BIT oprx16,X

BIT oprx8,X

BIT ,X

BIT oprx16,SP

BIT oprx8,SP

Bit Test (A) & (M)

(CCR Updated but Operands

Not Changed) 0––ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED5

9EE5

hh ll

ee ff

BLE rel Branch if Less Than

or Equal To

(Signed Operands) Branch if (Z)| (N V 1 ––––––REL 93 rr 3

BLO rel Branch if Lower

(Same as BCS) Branch if (C) = 1 ––––––REL 25 rr 3

BLS rel Branch if Lower or Same Branch if (C) | (Z) = 1 ––––––REL 23 rr 3

BLT rel Branch if Less Than

(Signed Operands) Branch if (N V 1––––––REL 91 rr 3

BMC rel Branch if Interrupt Mask

Clear Branch if (I) = 0 ––––––REL 2C rr 3

Table 44. HCS08 Instruction Set Summary (Sheet 2 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

b7 C

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BMI rel Branch if Minus Branch if (N) = 1 ––––––REL 2B rr 3

BMS rel Branch if Interrupt Mask

Set Branch if (I) = 1 ––––––REL 2D rr 3

BNE rel Branch if Not Equal Branch if (Z) = 0 ––––––REL 26 rr 3

BPL rel Branch if Plus Branch if (N) = 0 ––––––REL 2A rr 3

BRA rel Branch Always No Test ––––––REL 20 rr 3

BRCLR n,opr8a,rel Branch if Bit n in Memory

Clear Branch if (Mn) = 0 – – – – – Þ

DIR (b0)

DIR (b1)

DIR (b2)

DIR (b3)

DIR (b4)

DIR (b5)

DIR (b6)

DIR (b7)

dd rr

BRN rel Branch Never Uses 3 Bus Cycl es – – – – – – REL 21 rr 3

BRSET n,opr8a,rel Branch if Bit n in Memory

Set Branch if (Mn) = 1 – – – – – Þ

DIR (b0)

DIR (b1)

DIR (b2)

DIR (b3)

DIR (b4)

DIR (b5)

DIR (b6)

DIR (b7)

dd rr

BSET n,opr8a Set Bit n in Memory Mn  1 ––––––

DIR (b0)

DIR (b1)

DIR (b2)

DIR (b3)

DIR (b4)

DIR (b5)

DIR (b6)

DIR (b7)

BSR rel Branch to Subroutine

PC (PC) + 0x0002

push (PCL); SP  (SP) – 0x0001

push (PCH); SP  (SP) – 0x0001

PC  (PC) + rel

––––––REL ADrr 5

CBEQ opr8a,rel

CBEQA #opr8i,rel

CBEQX #opr8i,rel

CBEQ oprx8,X+,rel

CBEQ ,X+,rel

CBEQ oprx8,SP,rel

Compare and Branch if

Equal

Branch if (A) = (M)

Branch if (X) = (M)

Branch if (A) = (M)

––––––

DIR

IMM

IX1+

IX+

SP1

9E61

dd rr

ii rr

ff rr

rr ff

CLC Clear Carry Bit C  0 –––––0INH 98 1

CLI Clear Interrupt Mask Bit I  0 ––0–––INH 9A 1

CLR opr8a

CLRA

CLRX

CLRH

CLR oprx8,X

CLR ,X

CLR oprx8,SP

Clear

M  0x00

A  0x00

X  0x00

H  0x00

M  0x00

0––01–

DIR

INH

IX1

SP1

9E6F

Table 44. HCS08 Instruction Set Summary (Sheet 3 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

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CMP #opr8i

CMP opr8a

CMP opr16a

CMP oprx16,X

CMP oprx8,X

CMP ,X

CMP oprx16,SP

CMP oprx8,SP

Compare Accumulator

with Memory

(A) – (M)

(CCR Updated But Operands Not

Changed) Þ––ÞÞÞ

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED1

9EE1

hh ll

ee ff

COM opr8a

COMA

COMX

COM oprx8,X

COM ,X

COM oprx8,SP

Complement

(One’s Complement)

M  (M)= 0xFF – (M)

A  (A) = 0xFF – (A)

X  (X) = 0xFF – (X)

M  (M) = 0xFF – (M)

0––ÞÞ1

DIR

INH

IX1

SP1

9E63

CPHX opr16a

CPHX #opr16i

CPHX opr8a

CPHX oprx8,SP

Compare Index Register

(H:X) with Memory

(H:X) – (M:M + 0x0001)

(CCR Updated But Operands Not

Changed) Þ––ÞÞÞ

EXT

IMM

DIR

SP1

9EF3

hh ll

jj kk

CPX #opr8i

CPX opr8a

CPX opr16a

CPX oprx16,X

CPX oprx8,X

CPX ,X

CPX oprx16,SP

CPX oprx8,SP

Compare X (Index

Memory

(X) – (M)

(CCR Updated But Operands Not

Changed) Þ––ÞÞÞ

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED3

9EE3

hh ll

ee ff

DAA Decimal Adjust

Accumulator After ADD

or ADC of BCD Values (A)10 U––ÞÞÞINH 72 1

DBNZ opr8a,rel

DBNZA rel

DBNZX rel

DBNZ oprx8,X,rel

DBNZ ,X,rel

DBNZ oprx8,SP,rel

Decrement and Branch if

Not Zero

Decrement A, X, or M

Branch if (result) 0

DBNZX Affects X Not H ––––––

DIR

INH

IX1

SP1

9E6B

dd rr

ff rr

DEC opr8a

DECA

DECX

DEC oprx8,X

DEC ,X

DEC oprx8,SP

Decrement

M  (M) – 0x01

A  (A) – 0x01

X  (X) – 0x01

M  (M) – 0x01

Þ––ÞÞ–

DIR

INH

IX1

SP1

9E6A

DIV Divide A  (H:A)(X)

H  Remainder ––––ÞÞINH 52 6

EOR #opr8i

EOR opr8a

EOR opr16a

EOR oprx16,X

EOR oprx8,X

EOR ,X

EOR oprx16,SP

EOR oprx8,SP

Exclusive OR

Memory with

Accumulator A  (A  M) 0––ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED8

9EE8

hh ll

ee ff

INC opr8a

INCA

INCX

INC oprx8,X

INC ,X

INC oprx8,SP

Increment

M  (M) + 0x01

A  (A) + 0x01

X  (X) + 0x01

M  (M) + 0x01

Þ––ÞÞ–

DIR

INH

IX1

SP1

9E6C

Table 44. HCS08 Instruction Set Summary (Sheet 4 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 63

JMP opr8a

JMP opr16a

JMP oprx16,X

JMP oprx8,X

JMP ,X

Jump PC  Jump Address – – – – – –

DIR

EXT

IX2

IX1

hh ll

ee ff

JSR opr8a

JSR opr16a

JSR oprx16,X

JSR oprx8,X

JSR ,X

Jump to Subroutine

PC  (PC) + n (n = 1, 2, or 3)

Push (PCL); SP  (SP) – 0x0001

Push (PCH); SP  (SP) – 0x0001

PC  Unconditional Address

––––––

DIR

EXT

IX2

IX1

hh ll

ee ff

LDA #opr8i

LDA opr8a

LDA opr16a

LDA oprx16,X

LDA oprx8,X

LDA ,X

LDA oprx16,SP

LDA oprx8,SP

Load Accumulator from

Memory A  (M) 0––ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED6

9EE6

hh ll

ee ff

LDHX #opr16i

LDHX opr8a

LDHX opr16a

LDHX ,X

LDHX oprx16,X

LDHX oprx8,X

LDHX oprx8,SP

Load Index Register

(H:X) from Memory H:X M:M+ 0x00010––ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP1

9EAE

9EBE

9ECE

9EFE

jj kk

hh ll

ee ff

LDX #opr8i

LDX opr8a

LDX opr16a

LDX oprx16,X

LDX oprx8,X

LDX ,X

LDX oprx16,SP

LDX oprx8,SP

Load X (Index Register

Low) from Memory X  (M) 0––ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9EDE

9EEE

hh ll

ee ff

LSL opr8a

LSLA

LSLX

LSL oprx8,X

LSL ,X

LSL oprx8,SP

Logical Shift Left

(Same as ASL) Þ––ÞÞÞ

DIR

INH

IX1

SP1

9E68

LSR opr8a

LSRA

LSRX

LSR oprx8,X

LSR ,X

LSR oprx8,SP

Logical Shift Right Þ––0ÞÞ

DIR

INH

IX1

SP1

9E64

MOV opr8a,opr8a

MOV opr8a,X+

MOV #opr8i,opr8a

MOV ,X+,opr8a

Move

(M)destination (M)source

H:X  (H:X) + 0x0001 in

IX+/DIR and DIR/IX+ Modes

0––ÞÞ–

DIR/DIR

DIR/IX+

IMM/DIR

IX+/DIR

dd dd

ii dd

MUL Unsigned multiply X:A  (X)  (A) –0–––0INH 42 5

NEG opr8a

NEGA

NEGX

NEG oprx8,X

NEG ,X

NEG oprx8,SP

Negate

(Two’s Complement)

M  – (M) = 0x00 – (M)

A  – (A) = 0x00 – (A)

X  – (X) = 0x00 – (X)

M  – (M) = 0x00 – (M)

Þ––ÞÞÞ

DIR

INH

IX1

SP1

9E60

NOP No Operation Uses 1 Bus Cycle – – – – – – INH 9D 1

Table 44. HCS08 Instruction Set Summary (Sheet 5 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

Cb0

b7 0

b7 C0

FXTH870xD

Sensors

64 Freescale Semiconductor, Inc.

NSA Nibble Swap

Accumulator A  (A[3:0]:A[7:4]) – – – – – – INH 62 1

ORA #opr8i

ORA opr8a

ORA opr16a

ORA oprx16,X

ORA oprx8,X

ORA ,X

ORA oprx16,SP

ORA oprx8,SP

Inclusive OR

Accumulator and Memory A  (A) | (M) 0 – – ÞÞ–

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9EDA

9EEA

hh ll

ee ff

PSHA Push Accumulator onto

Stack Push (A); SP (SP) – 0x0001 – – – – – – INH 87 2

PSHH Push H (Index Register

High) onto Stack Push (H); SP (SP) – 0x0001 – – – – – – INH 8B 2

PSHX Push X (Index Register

Low) onto Stack Push (X); SP (SP) – 0x0001 – – – – – – INH 89 2

PULA Pull Accumulator from

Stack SP (SP + 0x0001); PullA––––––INH 86 3

PULH Pull H (Index Register

High) from Stack SP (SP + 0x0001); PullH––––––INH 8A 3

PULX Pull X (Index Register

Low) from Stack SP (SP + 0x0001); PullX––––––INH 88 3

ROL opr8a

ROLA

ROLX

ROL oprx8,X

ROL ,X

ROL oprx8,SP

Rotate Left through Carry Þ––ÞÞÞ

DIR

INH

IX1

SP1

9E69

ROR opr8a

RORA

RORX

ROR oprx8,X

ROR ,X

ROR oprx8,SP

Rotate Right through

Carry Þ––ÞÞÞ

DIR

INH

IX1

SP1

9E66

RSP Reset Stack Pointer SP  0xFF

(High Byte Not Affected) ––––––INH 9C 1

RTI Return from Interrupt

SP  (SP) + 0x0001; Pull (CCR)

SP  (SP) + 0x0001; Pull (A)

SP  (SP) + 0x0001; Pull (X)

SP  (SP) + 0x0001; Pull (PCH)

SP  (SP) + 0x0001; Pull (PCL)

ÞÞÞÞÞÞINH 80 9

RTS Return from Subroutine SP  SP + 0x0001PullPCH)

SP  SP + 0x0001; Pull (PCL) ––––––INH 81 6

SBC #opr8i

SBC opr8a

SBC opr16a

SBC oprx16,X

SBC oprx8,X

SBC ,X

SBC oprx16,SP

SBC oprx8,SP

Subtract with Carry A  (A) – (M) – (C) Þ––ÞÞÞ

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED2

9EE2

hh ll

ee ff

SEC Set Carry Bit C  1 –––––1INH 99 1

SEI Set Interrupt Mask Bit I  1 ––1–––INH 9B 1

Table 44. HCS08 Instruction Set Summary (Sheet 6 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

Cb0

b7 C

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 65

STA opr8a

STA opr16a

STA oprx16,X

STA oprx8,X

STA ,X

STA oprx16,SP

STA oprx8,SP

Store Accumulator in

Memory M (A) 0––ÞÞ–

DIR

EXT

IX2

IX1

SP2

SP1

9ED7

9EE7

hh ll

ee ff

STHX opr8a

STHX opr16a

STHX oprx8,SP Store H:X (Index Reg.) (M:M + 0x0001)  (H:X) 0 – – ÞÞ–DIR

EXT

SP1

9EFF

hh ll

STOP

Enable Interrupts:

Stop Processing

Refer to MCU Documen-

tation

I bit  0; Stop Processing – – 0 – – – INH 8E 2+

STX opr8a

STX opr16a

STX oprx16,X

STX oprx8,X

STX ,X

STX oprx16,SP

STX oprx8,SP

Store X (Low 8 Bits of

Index Register)

in Memory M (X) 0––ÞÞ–

DIR

EXT

IX2

IX1

SP2

SP1

9EDF

9EEF

hh ll

ee ff

SUB #opr8i

SUB opr8a

SUB opr16a

SUB oprx16,X

SUB oprx8,X

SUB ,X

SUB oprx16,SP

SUB oprx8,SP

Subtract A  (A) – (M) Þ––ÞÞÞ

IMM

DIR

EXT

IX2

IX1

SP2

SP1

9ED0

9EE0

hh ll

ee ff

SWI Software Interrupt

PC  (PC) + 0x0001

Push (PCL); SP  (SP) – 0x0001

Push (PCH); SP  (SP) – 0x0001

Push (X); SP  (SP) – 0x0001

Push (A); SP  (SP) – 0x0001

Push (CCR); SP  (SP) – 0x0001

I  1;

PCH  Interrupt Vector High Byte

PCL  Interrupt Vector Low Byte

––1–––INH 83 11

TAP Transfer Accumulator to

CCR CCR  (A) ÞÞÞÞÞÞINH 84 1

TAX Transfer Accumulator to

X (Index Register Low) X  (A) ––––––INH 97 1

TPA Transfer CCR to Accu-

mulator A  (CCR) ––––––INH 85 1

TST opr8a

TSTA

TSTX

TST oprx8,X

TST ,X

TST oprx8,SP

Test for Negative or Z ero

(M) – 0x00

(A) – 0x00

(X) – 0x00

(M) – 0x00

0––ÞÞ–

DIR

INH

IX1

SP1

9E6D

TSX Transfer SP to Index

Reg. H:X  (SP) + 0x0001 – – – – – – INH 95 2

TXA Transfer X (Index Reg.

Low) to Accumulator A  (X) ––––––INH 9F 1

TXS Transfer Index Reg. to

SP SP  (H:X) – 0x0001 – – – – – – INH 94 2

Table 44. HCS08 Instruction Set Summary (Sheet 7 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

FXTH870xD

Sensors

66 Freescale Semiconductor, Inc.

WAIT Enable Interrupts; Wait

for Interrupt I bit  0; Halt CPU – – 0 – – – INH 8F 2+

1. Bus clock frequency is one-half of the CPU clock frequency.

Table 45. Opcode Map (Sheet 1 of 2)

Bit-Manipulation Branch Read-Modify-Write Control Register/Memory

00 5

BRSET0

3DIR

10 5

BSET0

2DIR

20 3

BRA

2REL

30 5

NEG

2DIR

40 1

NEGA

1INH

50 1

NEGX

1INH

60 5

NEG

2IX1

70 4

NEG

1IX

80 9

RTI

1INH

90 3

BGE

2REL

A0 2

SUB

2IMM

B0 3

SUB

2DIR

C0 4

SUB

3 EXT

D0 4

SUB

3IX2

E0 3

SUB

2IX1

F0 3

SUB

1IX

01 5

BRCLR0

3DIR

11 5

BCLR0

2DIR

21 3

BRN

2REL

31 5

CBEQ

3DIR

41 4

CBEQA

3IMM

51 4

CBEQX

3IMM

61 5

CBEQ

3IX1+

71 5

CBEQ

2IX+

81 6

RTS

1INH

91 3

BLT

2REL

A1 2

CMP

2IMM

B1 3

CMP

2DIR

C1 4

CMP

3 EXT

D1 4

CMP

3IX2

E1 3

CMP

2IX1

F1 3

CMP

1IX

02 5

BRSET1

3DIR

12 5

BSET1

2DIR

22 3

BHI

2REL

32 5

LDHX

EXT

42 5

MUL

1INH

52 6

DIV

1INH

62 1

NSA

1INH

72 1

DAA

1INH

82 5+

BGND

1INH

92 3

BGT

2REL

A2 2

SBC

2IMM

B2 3

SBC

2DIR

C2 4

SBC

3 EXT

D2 4

SBC

3IX2

E2 3

SBC

2IX1

F2 3

SBC

1IX

03 5

BRCLR1

3DIR

13 5

BCLR1

2DIR

23 3

BLS

2REL

33 5

COM

2DIR

43 1

COMA

1INH

53 1

COMX

1INH

63 5

COM

2IX1

73 4

COM

1IX

83 11

SWI

1INH

93 3

BLE

2REL

A3 2

CPX

2IMM

B3 3

CPX

2DIR

C3 4

CPX

3 EXT

D3 4

CPX

3IX2

E3 3

CPX

2IX1

F3 3

CPX

1IX

04 5

BRSET2

3DIR

14 5

BSET2

2DIR

24 3

BCC

2REL

34 5

LSR

2DIR

44 1

LSRA

1INH

54 1

LSRX

1INH

64 5

LSR

2IX1

74 4

LSR

1IX

84 1

TAP

1INH

94 2

TXS

1INH

A4 2

AND

2IMM

B4 3

AND

2DIR

C4 4

AND

3 EXT

D4 4

AND

3IX2

E4 3

AND

2IX1

F4 3

AND

1IX

05 5

BRCLR2

3DIR

15 5

BCLR2

2DIR

25 3

BCS

2REL

35 4

STHX

2DIR

45 3

LDHX

3IMM

55 4

LDHX

2DIR

65 3

CPHX

3IMM

75 5

CPHX

2DIR

85 1

TPA

1INH

95 2

TSX

1INH

A5 2

BIT

2IMM

B5 3

BIT

2DIR

C5 4

BIT

3 EXT

D5 4

BIT

3IX2

E5 3

BIT

2IX1

F5 3

BIT

1IX

06 5

BRSET3

3DIR

16 5

BSET3

2DIR

26 3

BNE

2REL

36 5

ROR

2DIR

46 1

RORA

1INH

56 1

RORX

1INH

66 5

ROR

2IX1

76 4

ROR

1IX

86 3

PULA

1INH

96 5

STHX

EXT

A6 2

LDA

2IMM

B6 3

LDA

2DIR

C6 4

LDA

3 EXT

D6 4

LDA

3IX2

E6 3

LDA

2IX1

F6 3

LDA

1IX

07 5

BRCLR3

3DIR

17 5

BCLR3

2DIR

27 3

BEQ

2REL

37 5

ASR

2DIR

47 1

ASRA

1INH

57 1

ASRX

1INH

67 5

ASR

2IX1

77 4

ASR

1IX

87 2

PSHA

1INH

97 1

TAX

1INH

A7 2

AIS

2IMM

B7 3

STA

2DIR

C7 4

STA

3 EXT

D7 4

STA

3IX2

E7 3

STA

2IX1

F7 2

STA

1IX

08 5

BRSET4

3DIR

18 5

BSET4

2DIR

28 3

BHCC

2REL

38 5

LSL

2DIR

48 1

LSLA

1INH

58 1

LSLX

1INH

68 5

LSL

2IX1

78 4

LSL

1IX

88 3

PULX

1INH

98 1

CLC

1INH

A8 2

EOR

2IMM

B8 3

EOR

2DIR

C8 4

EOR

3 EXT

D8 4

EOR

3IX2

E8 3

EOR

2IX1

F8 3

EOR

1IX

09 5

BRCLR4

3DIR

19 5

BCLR4

2DIR

29 3

BHCS

2REL

39 5

ROL

2DIR

49 1

ROLA

1INH

59 1

ROLX

1INH

69 5

ROL

2IX1

79 4

ROL

1IX

89 2

PSHX

1INH

99 1

SEC

1INH

A9 2

ADC

2IMM

B9 3

ADC

2DIR

C9 4

ADC

3 EXT

D9 4

ADC

3IX2

E9 3

ADC

2IX1

F9 3

ADC

1IX

0A 5

BRSET5

3DIR

1A 5

BSET5

2DIR

2A 3

BPL

2REL

3A 5

DEC

2DIR

4A 1

DECA

1INH

5A 1

DECX

1INH

6A 5

DEC

2IX1

7A 4

DEC

1IX

8A 3

PULH

1INH

9A 1

CLI

1INH

AA 2

ORA

2IMM

BA 3

ORA

2DIR

CA 4

ORA

3 EXT

DA 4

ORA

3IX2

EA 3

ORA

2IX1

FA 3

ORA

1IX

0B 5

BRCLR5

3DIR

1B 5

BCLR5

2DIR

2B 3

BMI

2REL

3B 7

DBNZ

3DIR

4B 4

DBNZA

2INH

5B 4

DBNZX

2INH

6B 7

DBNZ

3IX1

7B 6

DBNZ

2IX

8B 2

PSHH

1INH

9B 1

SEI

1INH

AB 2

ADD

2IMM

BB 3

ADD

2DIR

CB 4

ADD

3 EXT

DB 4

ADD

3IX2

EB 3

ADD

2IX1

FB 3

ADD

1IX

0C 5

BRSET6

3DIR

1C 5

BSET6

2DIR

2C 3

BMC

2REL

3C 5

INC

2DIR

4C 1

INCA

1INH

5C 1

INCX

1INH

6C 5

INC

2IX1

7C 4

INC

1IX

8C 1

CLRH

1INH

9C 1

RSP

1INH

BC 3

JMP

2DIR

CC 4

JMP

3 EXT

DC 4

JMP

3IX2

EC 3

JMP

2IX1

FC 3

JMP

1IX

0D 5

BRCLR6

3DIR

1D 5

BCLR6

2DIR

2D 3

BMS

2REL

3D 4

TST

2DIR

4D 1

TSTA

1INH

5D 1

TSTX

1INH

6D 4

TST

2IX1

7D 3

TST

1IX

9D 1

NOP

1INH

AD 5

BSR

2REL

BD 5

JSR

2DIR

CD 6

JSR

3 EXT

DD 6

JSR

3IX2

ED 5

JSR

2IX1

FD 5

JSR

1IX

0E 5

BRSET7

3DIR

1E 5

BSET7

2DIR

2E 3

BIL

2REL

3E 6

CPHX

EXT

4E 5

MOV

3DD

5E 5

MOV

2DIX+

6E 4

MOV

3IMD

7E 5

MOV

2IX+D

8E 2+

STOP

1INH

Page 2 AE 2

LDX

2IMM

BE 3

LDX

2DIR

CE 4

LDX

3 EXT

DE 4

LDX

3IX2

EE 3

LDX

2IX1

FE 3

LDX

1IX

0F 5

BRCLR7

3DIR

1F 5

BCLR7

2DIR

2F 3

BIH

2REL

3F 5

CLR

2DIR

4F 1

CLRA

1INH

5F 1

CLRX

1INH

6F 5

CLR

2IX1

7F 4

CLR

1IX

8F 2+

WAIT

1INH

9F 1

TXA

1INH

AF 2

AIX

2IMM

BF 3

STX

2DIR

CF 4

STX

3 EXT

DF 4

STX

3IX2

EF 3

STX

2IX1

FF 2

STX

1IX

INH Inherent REL Relative SP1 Stack Pointer, 8-Bit Offset

IMM Immediate IX Indexed, No Offset SP2 Stack Pointer, 16-Bit Offset

DIR Direct IX1 Indexed, 8-Bit Offset IX+ Indexed, No Offset with

EXT Extended IX2 Indexed, 16-Bit Offset Post Increment

DD DIR to DIR IMD IMM to DIR IX1+ Indexed, 1-Byte Offset with

IX+D IX+ to DIR DIX+ DIR to IX+ Post Increment

Opcode in Hexadecimal

Number of Bytes

F0 3

SUB

1IX

HCS08 Cycles

Instruction Mnemonic

Addressing Mode

Table 44. HCS08 Instruction Set Summary (Sheet 8 of 8)

Source

Form Operation Description

Effect

on CCR

Address

Mode

Opcode

Operand

Bus Cycles(1)

VHINZC

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 67

Bit-Manipulation Branch Read-Modify-Write Control Register/Memory

9E60 6

NEG

3SP1

9ED0 5

SUB

4SP2

9EE0 4

SUB

3SP1

9E61 6

CBEQ

4SP1

9ED1 5

CMP

4SP2

9EE1 4

CMP

3SP1

9ED2 5

SBC

4SP2

9EE2 4

SBC

3SP1

9E63 6

COM

3SP1

9ED3 5

CPX

4SP2

9EE3 4

CPX

3SP1

9EF3 6

CPHX

3SP1

9E64 6

LSR

3SP1

9ED4 5

AND

4SP2

9EE4 4

AND

3SP1

9ED5 5

BIT

4SP2

9EE5 4

BIT

3SP1

9E66 6

ROR

3SP1

9ED6 5

LDA

4SP2

9EE6 4

LDA

3SP1

9E67 6

ASR

3SP1

9ED7 5

STA

4SP2

9EE7 4

STA

3SP1

9E68 6

LSL

3SP1

9ED8 5

EOR

4SP2

9EE8 4

EOR

3SP1

9E69 6

ROL

3SP1

9ED9 5

ADC

4SP2

9EE9 4

ADC

3SP1

9E6A 6

DEC

3SP1

9EDA 5

ORA

4SP2

9EEA 4

ORA

3SP1

9E6B 8

DBNZ

4SP1

9EDB 5

ADD

4SP2

9EEB 4

ADD

3SP1

9E6C 6

INC

3SP1

9E6D 5

TST

3SP1

9EAE 5

LDHX

2IX

9EBE 6

LDHX

4IX2

9ECE 5

LDHX

3IX1

9EDE 5

LDX

4SP2

9EEE 4

LDX

3SP1

9EFE 5

LDHX

3SP1

9E6F 6

CLR

3SP1

9EDF 5

STX

4SP2

9EEF 4

STX

3SP1

9EFF 5

STHX

3SP1

INH Inherent REL Relative SP1 Stack Pointer, 8-Bit Offset

IMM Immediate IX Indexed, No Offset SP2 Stack Pointer, 16-Bit Offset

DIR Direct IX1 Indexed, 8-Bit Offset IX+ Indexed, No Offset with

EXT Extended IX2 Indexed, 16-Bit Offset Post Increment

DD DIR to DIR IMD IMM to DIR IX1+ Indexed, 1-Byte Offset with

IX+D IX+ to DIR DIX+ DIR to IX+ Post Increment

Note: All Sheet 2 Opcodes are Preceded by the Page 2 Pr ebyte (9E)

Prebyte (9E) and

Opcode in

Hexadecimal

Number of Bytes

9E60 6

NEG

3SP1

HCS08 Cycles

Instruction Mnemonic

Addressing Mode

Table 45. Opcode Map (Sheet 2 of 2)

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9 Timer Pulse-Width Module

The timer pulse-width module (TPM1) is a two channel timer system that supports traditional input capture, output compare, or

edge-aligned PWM on each channel. All the features and functions of the TPM1 are as described in the MC9S08RC16 product

specification. The user has the option to connect the two timer channels to the PTA2:3 pins, if those pins are not needed for an

LFR channel or other general purpose I/O function. The following clock source and frequency selections are available using the

system option register 2 as shown in Figure 23 and Table 27.

In addition one channel of the TPM1 can be connected to a 500 kHz clock (DX) derived from the crystal oscillator on the RFM.

This selection is made by setting the TPM1 to use an external clock. This clock source allows time calibration of the LFO as

described in the Section 14.

9.1 Features

The TPM1 has the following features:

• May be configured for buffered, center-alig ned pulse-width modulation (CPWM) on all channels

• Clock sources independently selectable

• Selectable clock sources (device dependent): bus clock, fixed system clock

• Clock prescaler taps for divide by 1, 2, 4, 8, 16, 32, 64, or 128

• 16-bit free-running or up/down (CPWM) count operation

• 16-bit modulus register to control counter range

• Timer system enable

• One interrupt per channel plus a terminal count interrupt

• Channel features:

— Each channel may be input capture, output compare, or buffered edge-aligned PWM

— Rising-edge, falling-edge, or any-ed ge input capture trigger

— Set, clear, or toggle output compare action

— Selectable polarity on PWM outputs

9.2 TPM1 Configuration Information

The device provides one two-channel timer/pulse-width modulator (TPM1).

An easy way to measure the low frequency oscillator (LFO) is to connect the LFO dire ctly to TPM1 channel 0. The LFOSEL bit

in the SOPTZ determines whether TPM1CH0 is connected to PTAZ or the LFO.

TPM1 clock source selection for the TPM1 is shown in the table below.

Table 46. TPM1 Clock Source Selection

CLKSB CLKSA Clock Source

0 0 No source; TPM1 disabled

01 BUSCLK

1 0 unused

1 1 Internal DX pin

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9.2.1 Block Diagram

Figure 42 shows the structure of a TPM1.

Figure 42. TPM1 Block Diagram

The central component of the TPM1 is the 16-bit counter that can operate as a free-running counter, a modulo counter , or an up-

/down-counter when the TPM1 is configured for center-aligned PWM. The TPM1 counter (when operating in normal up-counting

mode) provides the timing reference for the input capture, output compare, and edge-aligned PWM functions. The timer counter

modulo registers, TPMMODH:TPMMODL, control the modulo value of the counter. (The values 0x0000 or 0xFFFF effectively

make the counter free running.) Software can read the counter value at any ti me without affecting the counting sequence. Any

write to either byte of the TPMCNT counter resets the counter regardless of the data value written.

All TPM1 channels are programmable independently as input capture, output compare, or buffered edge-aligned PWM channels.

9.3 External Signal Description

When any pin associated with the timer is configured as a timer input, a passive pullup can be enabled. After reset, the TPM1

modules are disabled and all pins default to general-purpose inputs with the passive pullups disabled.

Each TPM1 channel is associated with an I/O pin on the MCU. The function of this pin de pends on the configuration of the

channel. In some cases, no pin function is needed so the pin reverts to being controlled by general-purpose I/O controls. When

a timer has control of a port pin, the port data and data direction registers do not affect the related pin(s). See the Section 2 for

additional information about shared pin functions.

PRESCALE AND SELECT

16-BIT COMPARATOR

MAIN 16-BIT COUNTER

16-BIT COMPARATOR

16-BIT LATCH

PORT

16-BIT COMPARATOR

16-BIT LATCH

CHANNEL 0

CHANNEL 1

INTERNAL BUS

LOGIC

INTERRUPT

PORT

LOGIC

COUNTER RESET

DIVIDE BY

CLOCK SOURCE

OFF, BUS, XCLK, EXT

BUSCLK SELECT

SYNC

INTERRUPT

1, 2, 4, 8, 16, 32, 64, or 128

LOGIC

CLKSA

CLKSB PS2 PS1 PS0

CPWMS

TOIE

TOF

ELS0A

CH0F

ELS0B

ELS1B ELS1A

CH1F

CH0IE

CH1IE

MS1B

MS0B MS0A

MS1A

TPMMODH:TPMMO

TPMC0VH:TPMC0VL

TPMC1VH:TPMC1VL

TPMCH1

TPMCH0

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9.4 Register Definition

The TPM1 includes:

• An 8-bit status and control register (TPMSC)

• A 16-bit counter (TPMCNTH:TPMCNTL)

• A 16-bit modulo register (T P MMODH:TPMM ODL)

Each timer channel has:

• An 8-bit status and control register (TPMCnSC)

• A 16-bit channel value register (TPMCnVH:TPMCnVL)

9.4.1 Timer Status and Control Register (TPM1SC)

TPM1SC contains the overflow status flag and control bits that are used to configure the interrupt enable, TPM1 configuration,

clock source, and prescale divisor. These controls relate to all channels within this timer module.

$0010 76543210

RTOF TOIE CPWMS CLKSB CLKSA PS2 PS1 PS0

Reset 00000000

= Reserved

Figure 43. Timer Status and Control Register (TPM1SC)

Table 47. TPM1SC Regis t er Field Descriptions

Field Description

TOF

Timer Overflow Flag — This flag is set when the TPM1 counter changes to 0x0000 after reaching the modulo value

programmed in the TPM1 counter modulo registers. When the TPM1 is configured for CPWM, TOF is set after the counter has

reached the value in the modulo register , at the transition to the next lower count value. Clear TOF by reading the TPM1 status

and control register when TOF is set and then writing a 0 to TOF. If another TPM1 overflow occurs before the clearing sequence

is complete, the sequence is reset so TOF would remain set after the clear sequence was completed for the earlier TOF. Reset

clears TOF. Writing a 1 to TOF has no effect.

0 TPM1 counter has not reached modulo value or overflow

1 TPM1 counter has overflowed

TOIE

Timer Overflow Interrupt Enable — This read/write bit enables TPM1 overflow interrupts. If TOIE is set, an interrupt is

generated when TOF equals 1. Reset clears TOIE.

0 TOF interrupts inhibited (use software polling)

1 TOF interrupts enabled

CPWMS

Center-Aligned PWM Select — This read/write bit selects CPWM operating mode. Reset clears this bit so the TPM1 operates

in up-counting mode for input capture, output compare, and edge-aligned PWM functions. Setting CPWMS reconfigures the

TPM1 to operate in up-/down-counting mode for CPWM functions. Reset clears CPWMS.

0 All TPM channels operate as input capture, output compare, or edge-aligned PWM mode as selected by the MSnB:MSnA

control bits in each channel’s status and control register

1 All TPM channels operate in center-aligned PWM mode

4:3

CLKS[B:A]

Clock Source Select — As shown in Table 46, this 2-bit field is used to disable the TPM1 system or select one of three clock

sources to drive the counter prescaler. The internal DX source is synchronized to the bus clock by an on-chip synchronization

circuit.

2:0

PS[2:0]

Prescale Divisor Select — This 3-bit field selects one of eight divisors for the TPM1 clock input as shown in Table 48. This

prescaler is located after any clock source synchronization or clock source selection, so it affects whatever clock source is

selected to drive the TPM1 system.

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9.4.2 Timer Counter Registers (TPM1CNTH:TPM1CNTL)

The two read-only TPM1 counter registers contain the high and low bytes of the value in the TPM1 counter . Reading either byte

(TPM1CNTH or TPM1CNTL) latches the contents of both bytes into a buffer where they remain latched until the other byte is

read. This allows coherent 16-bit reads in either order . The coherency mechanism is automatically restarted by an MCU reset, a

write of any value to TPM1CNTH or TPM1CNTL, or any write to the timer status/control register (TPM1SC).

Reset clears the TPM1 counter registers.

When BACKGROUND mode is active, the timer counter and the coherency mechanism are frozen su ch that the buffer latches

remain in the state they were in when the BACKGROUND mode became active even if one or both bytes of the counter are read

while BACKGROUND mode is active.

9.4.3 Timer Counter Modulo Registers (TPM1MODH:TPM1MODL)

The read/write TPM1 modulo registers contain the modulo value for the TPM1 counte r. After the TPM1 counter reaches the

modulo value, the TPM1 counter resumes counting from 0x0000 at the next clock (CPWMS = 0) or starts counting down

(CPWMS = 1), and the overflow flag (TOF) becomes set. Writing to TPM1MODH or TPM1MODL inhibits TOF and overflow

interrupts until the other byte is written. Reset sets the TPM1 counter modulo registers to 0x0000, which results in a free-running

timer counter (modulo disabled).

Table 48. Prescale Divisor Selection

PS2:PS1:PS0 TPM1 Clock Source Divided-By

0:0:0 1

0:0:1 2

0:1:0 4

0:1:1 8

1:0:0 16

1:0:1 32

1:1:0 64

1:1:1 128

$0011 76543210

RBit 15 14 13 12 11 10 9 Bit 8

WAny write to TPMCNTH clears the 16-bit counter.

Reset 00000000

Figure 44. Timer Counter Register High (TPM1CNTH)

$0012 76543210

RBit 7654321Bit 0

WAny write to TPMCNTL clears the 16-bit counter.

Reset 00000000

Figure 45. Timer Counter Register Low (TPM1CNTL)

$0013 7 6 5 43210

RBit 15 14 13 12 11 10 9 Bit 8

Reset 00000000

Figure 46. Timer Counter Modulo Register High (TPM1MODH)

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It is good pr actice to wait fo r an overflow i nterrupt so both b ytes of the modulo register can be written well before a new overflow.

An alternative approach is to reset the TPM1 counter before writing to the TPM1 modulo registers to avoid confusion about when

the first counter overflow will occur.

9.4.4 Timer Channel 0 Status and Control Register (TPM1C0SC)

TPM1C0SC contains the channel interrupt status flag and control bits that are used to configure the interrupt enable, channel

configuration, and pin function.

$001476543210

RBit 7654321Bit 0

Reset 00000000

Figure 47. Timer Counter Modulo Register Low (TPM1MODL)

$0015 76543210

RCH0F CH0IE MS0B MS0A ELS0B ELS0A 00

Reset 00000000

= Reserved

Figure 48. Timer Channel 0 Status and Control Register (TPM1C0SC)

Table 49. TPM1C0SC Register Field Descriptions

Field Description

CH0F

Channel 0 Flag — When channel n is configured for input capture, this flag bit is set when an active edge occurs on the channel

n pin. When channel 0 is an output compare or edge-aligned PWM channel, CH0F is set when the value in the TPM1 counter

registers matches the value in the TPM1 channel 0 value registers. This flag is seldom used with center-aligned PWMs because

it is set every time the counter matches the channel value register, which correspond to both edges of the active duty cycle

period.

A corresponding interrupt is requested when CH0F is set and interrupts are enabled (CH0IE = 1). Clear CH0F by reading

TPM1C0SC while CH0F is set and then writing a 0 to CH0F. If another interrupt request occurs before the clearing sequence

is complete, the sequence is reset so CH0F would remain set after the clear sequence was completed for the earlier CH0F.

This is done so a CH0F interrupt request cannot be lost by clearing a previous CH0F. Reset clears CH0F. Writing a 1 to CH0F

has no effect.

0 No input capture or output compare event occurred on channel 0

1 Input capture or output compare event occurred on channel 0

CH0IE

Channel 0 Interrupt Enable — This read/write bit enables interrupts from channel 0. Reset clears CH0IE.

0 Channel 0 interrupt requests disabled (use software polling)

1 Cha nnel 0 interrupt requests enabled

MS0B Mode Select B for TPM1 Channel 0 — When CPWMS = 0, MS0B = 1 configures TPM1 channel 0 for edge-aligned PWM

mode. For a summary of channel mode and setup controls, refer to Table 50.

MS0A Mode Select A for TPM1 Channel 0 — When CPWMS = 0 and MS0B = 0, MS0A configures TPM1 channel 0 for input capture

mode or output compare mode. Refer to Table 50 for a summary of channel mode and setup controls.

3:2

ELS0[B:A]

Edge/Level Select Bits — Depending on the operating mode for the timer channel as set by CPWMS:MS0B:MSnA and shown

in Table 50, these bits select the polarity of the input edge that triggers an input capture event, select the level that will be driven

in response to an output compare match, or select the polarity of the PWM output.

Setting ELS0B:ELS0A to 0:0 configures the related timer pin as a general-purpose I/O pin unrelated to any timer channel

functions. This function is typically used to temporarily disable an input capture channel or to make the timer pin available as a

general-purpose I/O pin when the associated timer channel is set up as a software timer that does not require the use of a pin.

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If the associated port pin is not stable for at least two bus clock cycles before changing to input capture mode, it is possible to

get an unexpected indication of an edge trigger. T ypically , a program would clear status flags after changing channel configuration

bits and before enabling channel interrupts or using the status flags to avoid an y unexpected behavior.

9.4.5 Timer Channel Value Registers (TPM1C0VH:TPM1C0VL)

These read/write registers contain the captured TPM1 counte r value of the input capt ure function or the output compare value

for the output compare or PWM functions. The channel value registers are cleared by reset.

In input capture mode, reading either byte (TPM1C0VH or TPM1C0VL) latches the contents of both bytes into a buffer where

they remain latched until the other byte is read. This latching mechanism also resets (becomes unlatched) when the TPM1C0SC

In output compare or PWM modes, writing to either byte (TPM1C0VH or TPM1C0VL) latches the value into a buffer . When both

bytes have been written, they are transferred as a coherent 16-bit value into the timer channel value registers. This latching

mechanism may be manually reset by writing to the TPM1C0SC register.

This latching mechanism allows coherent 16-bit writes in either order, wh ich is friendly to various compil er implementations.

Table 50. Mode, Edge, and Level Selection

CPWMS MS0B:MS0A ELS0B:ELS0A Mode Configuration

XXX 00

Pin not used for TPM1 channel; use as an external clock for the TPM1 or revert

to general-purpose I/O

Input capture

Capture on rising edge only

10 Capture on falling edge only

11 Capture on rising or falling edge

Output compare

Software compare only

01 Toggle output on compare

10 Clear output on compare

11 Set output on compare

1X 10 Edge-aligned

PWM High-true pulses (clear output on compare)

X1 Low-true pulses (set output on compare)

1XX 10 Center-aligned

PWM High-true pulses (clear output on compare-up)

X1 Low-true pulses (set output on compare-up)

$001676543210

RBit 15 14 13 12 11 10 9 Bit 8

Reset 00000000

Figure 49. Timer Channel 0 Value Register High (TPM1C0VH)

$001776543210

RBit 7654321Bit 0

Reset 00000000

Figure 50. Timer Channel 0 Value Register Low (TPM1C0VL)

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9.4.6 Timer Channel 1 Status and Control Register (TPM1C1SC)

TPM1C1SC contains the channel interrupt status flag and control bits that are used to configure the interrupt enable, channel

configuration, and pin function.

$0018 76543210

RCH1F CH1IE MS1B MS1A ELS1B ELS1A 00

Reset 00000000

= Reserved

Figure 51. Timer Channel 1 Status and Control Register (TPM1C1SC)

Table 51. TPM1C1SC Register Field Descriptions

Field Description

CH1F

Channel 1 Flag — When channel n is configured for input capture, this flag bit is set when an active edge occurs on the channel

n pin. When channel 1 is an output compare or edge-aligned PWM channel, CH1F is set when the value in the TPM1 counter

registers matches the value in the TPM1 channel 1 value registers. This flag is seldom used with center-aligned PWMs because

it is set every time the counter matches the channel value register, which correspond to both edges of the active duty cycle

period.

A corresponding interrupt is requested when CH1F is set and interrupts are enabled (CH1IE = 1). Clear CH1F by reading

TPM1C1SC while CH1F is set and then writing a 0 to CH1F. If another interrupt request occurs before the clearing sequence

is complete, the sequence is reset so CH1F would remain set after the clear sequence was completed for the earlier CH1F.

This is done so a CH1F interrupt request cannot be lost by clearing a previous CH1F. Reset clears CH1F. Writing a 1 to CH1F

has no effect.

0 No input capture or output compare event occurred on channel 1

1 Input capture or output compare event occurred on channel 1

CH1IE

Channel 1 Interrupt Enable — This read/write bit enables interrupts from channel 1. Reset clears CH1IE.

0 Channel 1 interrupt requests disabled (use software polling)

1 Cha nnel 1 interrupt requests enabled

MS1B Mode Select B for TPM1 Channel 1 — When CPWMS = 0, MS1B = 1 configures TPM1 channel 1 for edge-aligned PWM

mode. For a summary of channel mode and setup controls, refer to Table 50.

MS1A Mode Select A for TPM1 Channel 1 — When CPWMS = 0 and MS1B = 0, MS1A configures TPM1 channel 1 for input capture

mode or output compare mode. Refer to Table 50 for a summary of channel mode and setup controls.

3:2

ELS1[B:A]

Edge/Level Select Bits — Depending on the operating mode for the timer channel as set by CPWMS:MS1B:MS1A and shown

in Table 50, these bits select the polarity of the input edge that triggers an input capture event, select the level that will be driven

in response to an output compare match, or select the polarity of the PWM output.

Setting ELS1B:ELS1A to 0:0 configures the related timer pin as a general-purpose I/O pin unrelated to any timer channel

functions. This function is typically used to temporarily disable an input capture channel or to make the timer pin available as a

general-purpose I/O pin when the associated timer channel is set up as a software timer that does not require the use of a pin.

Table 52. Mode, Edge, and Level Selection

CPWMS MS1B:MS1A ELS1B:ELS1A Mode Configuration

XXX 00

Pin not used for TPM1 channel; use as an external clock for the TPM1 or revert

to general-purpose I/O

Input capture

Capture on rising edge only

10 Capture on falling edge only

11 Capture on rising or falling edge

Output compare

Software compare only

01 Toggle output on compare

10 Clear output on compare

11 Set output on compare

1X 10 Edge-aligned

PWM High-true pulses (clear output on compare)

X1 Low-true pulses (set output on compare)

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If the associated port pin is not stable for at least two bus clock cycles before changing to input capture mode, it is possible to

get an unexpected indication of an edge trigger. T ypically , a program would clear status flags after changing channel configuration

bits and before enabling channel interrupts or using the status flags to avoid an y unexpected behavior.

9.4.7 Timer Channel Value Registers (TPM1C1VH:TPM1C1VL)

These read/write registers contain the captured TPM1 counte r value of the input capt ure function or the output compare value

for the output compare or PWM functions. The channel value registers are cleared by reset.

In input capture mode, reading either byte (TPM1C1VH or TPM1C1VL) latches the contents of both bytes into a buffer where

they remain latched until the other byte is read. This latching mechanism also resets (becomes unlatched) when the TPM1C1SC

In output compare or PWM modes, writing to either byte (TPM1C1VH or TPM1C1VL) latches the value into a buffer . When both

bytes have been written, they are transferred as a coherent 16-bit value into the timer channel value registers. This latching

mechanism may be manually reset by writing to the TPM1C1SC register.

This latching mechanism allows coherent 16-bit writes in either order, wh ich is friendly to various compil er implementations.

9.5 Functional Description

All TPM1 functions are associated with a main 16-bit counter that allows flexible selection of the clock source and prescale divisor.

A 16-bit modulo register also is associated with the main 16-bit counter in the TPM1. Each TPM1 channel is optionally associated

with an MCU pin and a maskable inte rrupt function.

The TPM1 has center-aligned PWM capabilities controlled by the CPWMS control bit in TPM1SC. When CPWM S is set to 1,

timer counter TPM1CNT changes to an up-/down-counter and all channels in the associated TPM1 act as center-aligned PWM

channels. When CPWMS = 0, each channel can independently be conf igured to operate in input capture, output compare, or

buffered edge-aligned PWM mode.

The following sections describe the main 16-bit counter and each of the timer operating modes (input capture, output compare,

edge-aligned PWM, and center-aligned PWM). Because details of pin operatio n and interrupt activity depend on the operating

mode, these topics are covered in the associated mode sections.

9.5.1 Counter

All timer functions are based on the main 16-bit counter (TPM1CNTH:TPM1CNTL). This section discusses selection of the clock

source, up-counting vs. up-/down-counting, end-of-count overflow, and manual counter reset.

After any MCU reset, CLKSB:CLKSA = 0:0 so no clock source is selected and the TPM1 is inactive. Normally, CLKSB:CLKSA

would be set to 0:1 so the bus clock drives the timer counter. The clock source for the TPM1 can be selected to be off, the bus

1XX 10 Center-aligned

PWM High-true pulses (clear output on compare-up)

X1 Low-true pulses (set output on compare-up)

$001976543210

RBit 15 14 13 12 11 10 9 Bit 8

Reset 00000000

Figure 52. Timer Channel 1 Value Register High (TPM1C1VH)

$001A76543210

RBit 7654321Bit 0

Reset 00000000

Figure 53. Timer Channel 1 Value Register Low (TPM1C1VL)

Table 52. Mode, Edge, and Lev el Selection (continued)

CPWMS MS1B:MS1A ELS1B:ELS1A Mode Configuration

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clock (BUSCLK), the fixed system clock (XCLK), or an external input. The maximum frequency allowed for the external clock

option is one-fourth the bus rate. Refer to Section 9.4.1 and Table 49 for more information about clock source selection.

When the microcontroller is in ACTIVE BACKGROUND mode, the TPM1 temporarily suspends all counting until the

microcontroller returns to normal user operating mode. During STOP mode, all TPM1 clocks are stopped; therefore, the TPM1

is effectively disabled until clocks resume. During WAIT mode, the TPM1 continues to operate normally.

The main 16-bit counter has two counting modes. When center-aligned PWM is selected (CPWMS = 1), the counter operates in

up-/down-counting mode. Otherwi se, the coun ter operates as a simple up-counter. As an up-counte r, the main 16-bit counter

counts from 0x0000 through its terminal count and then continues with 0x0000. The terminal count is 0xFFFF or a modulus value

in TPM1MODH:TPM1MODL.

When center-aligned PWM operation is specified, the counter counts upward from 0x0000 through its terminal count and then

counts downward to 0x0000 where it returns to up-counting. Both 0x0000 and the terminal count value (value in

TPM1MODH:TPM1MODL) are normal length counts (one timer clock period long).

An interrupt flag and enable are associated with the main 16-bit counter. The timer overflow flag (TOF) is a software-accessible

indication that the timer counte r has overflowed. The enable signal selects between software polling (TOIE = 0) where no

hardware interrupt is generated, or interrupt-driven operation (TOIE = 1) where a static hardware interrupt is automatically

generated whenever the TOF flag is 1.

The conditions that cause TOF to become set depend on the counting mode (up or up/down). In up-counting mode, the main 16-

bit counter counts from 0x0000 through 0xFFFF and overflows to 0x0000 on the next counting clock. TOF becomes set at the

transition from 0xFFFF to 0x0000. When a modulus limit is set, TOF becomes set at the transition from the value set in the

modulus register to 0x0000. When the main 16-bit counter is operating in up-/down-counting mode, the TOF flag gets set as the

counter changes direction at the transition from the value set in the modulus register and the next lower count value. This

corresponds to the end of a PWM period. (The 0x0000 count value corresponds to the center of a period.)

Because the HC S 08 M CU is an 8-bit archi te cture, a coherency mechanism is built into the timer counter for read operations.

Whenever either byte of the counter is read (TPM1CNTH or TPM1CNTL), both bytes are captured into a buffer so when the other

byte is read, the value will represent the other byte of the count at the time the first byte was read. The counter continues to count

normally, but no new value can be read from either byte until both bytes of the old cou nt have been read.

The main timer counter can be reset manually at any time by writing an y value to either byte of the timer count TPM1CNTH or

TPM1CNTL. Resetting the counter in this manner also resets the coherency mechanism in case only one byte of the counter was

read before resetting the count.

9.5.2 Channel Mode Selection

Provided CPWMS = 0 (center-aligned PWM operation is not specified), the MSnB and MSnA control bits in the channel n status

and control registers determine the basic mode of operation for the corresponding channel. Choices include input capture, output

compare, and buffered edge-aligned PWM.

Input Capture Mode

With the input capture function, the TPM1 can capture the time at which an external event occurs. When an active edge occurs

on the pin of an input capture channel, the TPM1 latches th e contents of the TPM1 counter into the channel value registers

(TPM1CnVH:TPM1CnVL). Rising edges, fallin g edges, or any edge may be chosen as the active edge tha t triggers an input

capture.

When either byte of the 16-bit capture register is read, both bytes are latched into a buffer to support coherent 16-bit accesses

regardless of order. The coherency sequen ce can be manually reset by writing to the channel status/control register

(TPM1CnSC).

An input capture event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.

Output Compare Mode

With the output compare function, the TPM1 can generate timed pulses with programmable position, polarity, duration, and

frequency. When the counter reaches the value in the channel value registers of an output compare channel, the TPM1 can set,

clear, or toggle the channel pin.

In output compare mode, values are transferred to the corresponding timer channel value registers only after both 8-bit bytes of

a 16-bit register have been written. Th is coherency sequence can be manually reset by writing to the channel status/control

An output compare event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.

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Edge-Aligned PWM Mode

This type of PWM output uses the normal up-counting mode of the timer counter (CPWMS = 0) and can be used when other

channels in the same TPM1 are configured for input capture or output compare functions. The period of this PWM signal is

determined by the setting in the modulus register (TPM1MODH:TPM1MODL). The duty cycle is determined by the setting in the

timer channel value register (TPM1CnVH:TPM1CnVL). The polarity of this PWM signal is determined by the setting in the ELSnA

control bit. Duty cycle cases of 0 percent and 100 percent are possible.

As Figure 54 shows, the output compare value in the TPM1 channel registers determines the pulse width (duty cycle) of the PWM

signal. The time between the modulus overflow and the output compare is the pulse width. If ELSnA = 0, the counter overflo w

forces the PWM signal high and the output compare forces the PWM signal low. If ELSnA = 1, the counter overflow forces the

PWM signal low and the output compare forces the PWM signal high.

Figure 54. PWM Period and Pulse Width (ELSnA = 0)

When the channel value register is set to 0x0000, the duty cycle is 0 percent. By setting the timer channel value register

(TPMCnVH:TPMCnVL) to a value greater than the modulus setting, 100% duty cycle can be achieved. This implies that the

modulus setting must be less than 0xFFFF to get 100% duty cycle.

Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to ensure coherent 16-bit

updates and to avoid unexpected PWM pulse widths. Writes to either register, TPM1CnVH or TPM1CnVL, write to buffer

registers. In edge-PWM mode, values are transferred to the corresponding timer channel registers only after both 8-bit bytes of

a 16-bit register have been written and the value in the 1TPMCNTH:TPM1CNTL counter is 0x0000. (The new duty cycle does

not take effect until the next full period.)

9.5.3 Center-Aligned PWM Mode

This type of PWM output uses the up-/down-counting mode of the timer counter (CPWMS = 1). The output compare value in

TPM1CnVH:TPM1CnVL determines the pulse width (duty cycle) of the PWM signal and the period is determined by the value in

TPM1MODH:TPM1MODL. TPM1MODH:TPM1MODL should be kept in the range of 0x0001 to 0x7FFF because values outside

this range can produce ambiguous results. ELS0A will determine the polarity of the CPWM output.

pulse width =2 x (TPM1CnVH:TPM1CnVL)

period = 2 x (TPM1MODH:TPM1MODL);

for TPM1MODH:TPM1MODL = 0x0001–0x7FFF

If the channel value register TPM1CnVH:TPM1CnVL is zero or negative (bit 15 set), the duty cycle will be 0%. If

TPM1CnVH:TPM1CnVL is a positive value (bit 15 clear) and is greater than the (nonzero) modulus setting, the duty cycle will be

100% because the duty cycle compare will never occur. This implies the usable range of periods set by the modulus register is

0x0001 through 0x7FFE (0x7FFF if generation of 100% duty cycle is not necessary). This is not a significant limitation because

the resulting period is much longer than required for normal applicatio ns.

TPM1MODH:TPM1MODL = 0x0000 is a special case that should not be used with center-aligned PWM mode. When

CPWMS = 0, this case corresponds to the counter running free from 0x0000 through 0xFFFF, but when CPWMS = 1 the counter

needs a valid match to the modulus register somewhere other than at 0x0000 in order to change directions from up-counting to

down-counting.

Figure 55 shows the output compare value in the TPM1 channel registers (multiplied by 2), which determines the pulse width

(duty cycle) of the CPWM signal. If ELSnA = 0, the compare match while counting up forces the CPWM output signal low and a

compare match while counting down forces the output high. The counter counts up until it reaches the modulo setting in

TPM1MODH:TPM1MODL, then counts down until it reaches zero. This sets the period equal to two times

TPM1MODH:TPM1MODL.

PERIOD

PULSE

WIDTH

OVERFLOW OVERFLOW OVERFLOW

OUTPUT

COMPARE OUTPUT

COMPARE

OUTPUT

COMPARE

TPMCH

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Figure 55. CPWM Period and Pulse Width (ELSnA = 0)

Center-aligned PWM outputs typically produce less noise than edge -aligned PWMs because fewer I/O pin transitions are lined

up at the same system clock edge. This type of PWM is also re quired for some types of motor drives.

Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to ensure coherent 16-bit

updates and to avoid unexpected PWM pulse widths. Writes to any of the registers, TPM1MODH, TPM1MODL, TPM1CnVH, and

TPM1CnVL, actually write to buffer registers. V alues are transferred to the corresponding timer channel registers only after both

8-bit bytes of a 16-bit register have been written and the timer counter overflows (reverses direction from up-counting to down-

counting at the end of the terminal count in the modulus register). This TPM1CNT overflow requirement only applie s to PWM

channels, not output compares.

Optionally, when TPM1CNTH:TPM1CNTL = T PM1 MODH:TPM1MODL, the TPM1 can generate a TOF interrupt at the end of

this count. The user can choose to reload any number of the PWM buffers, and they will all update simultaneously at the start of

a new period.

Writing to TPM1SC cancels any values written to TPM1MODH and/or TPM1MODL and resets the coherency mechanism for the

modulo registers. Writing to TPM1C0SC cancels any values written to the channel value registers and resets the coherency

mechanism for TPM1C0VH:TPM1C0VL.

9.6 TPM1 Interrupts

The TPM1 generates an optional interrupt for the main counter overflow and an interrup t for each channel. The meaning of

channel interrupts depends on the mode of operation for each channel. If the channel is configured for input capture, the interrupt

flag is set each time the selected input capture edge is recogn ized. If the channel is configured for output compare or PWM

modes, the interrupt flag is set each time the main timer counter matches the value in the 16-bit channel value register. See

Section 5 for absolute interrupt vector addresses, priority, and local interrupt mask control bits.

For each interrupt source in the TPM1, a flag bit is set on recognition of the interrupt condition such as timer overflow, channel

input capture, or output compare events. This flag may be read (polled) by software to verify that the action has occurred, or an

associated enable bit (TOIE or CHnIE) can be set to enable hardware interrupt generation. While the interrupt enable bit is set,

a static interrupt will be generated whenever the associated interrupt flag equals 1. It is the responsibility of user software to

perform a sequence of steps to clear the interrupt flag before returning from the interrup t service routin e.

9.6.1 Clearing Timer Interrupt Flags

TPM1 interrupt flags are cleared by a two-step process that includes a read of the flag bit while it is set (1) followed by a write of

0 to the bit. If a new event is detected between these two steps, the sequence is reset and the interrupt flag remains set after the

second step to avoid the possibility of missing the new event.

9.6.2 Timer Overflow Interrupt Description

The conditions tha t cause TOF to become set depend on the counting mode (up or up/down). In up-counting mode, the 16-bit

timer counter counts from 0x0000 through 0xFFFF and overflows to 0x0000 on the next counting clock. TOF becomes set at the

transition from 0xFFFF to 0x0000. When a modulus limit is set, TOF becomes set at the transition from the value set in the

modulus register to 0x0000. When th e counter is operating in up-/down-counti ng mode, the TOF flag gets set as the counter

changes direction at the transition from the value set in the mo dulus register and the next lower count value. This corresponds

to the end of a PWM period. (The 0x0000 count value corresponds to the center of a period.)

PERIOD 2x

PULSE WIDTH

COUNT =

COUNT = 0 OUTPUT

COMPARE

(COUNT UP)

OUTPUT

COMPARE

(COUNT DOWN) COUNT =

TPMMODH:TPMMODL

TPMMODH:TPMMODL TPMMODH:TPMMODL

TPM1CHn

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9.6.3 Channel Event Interrupt Description

The meaning of channel interrupts depends on the current mode of the channel (input capture, output compare, edge-aligned

PWM, or center-aligned PWM).

When a channel is configured as an input capture channel, the ELSnB:ELSnA control bits select rising edges, falling edges, any

edge, or no edge (off) as the edge that triggers an input capture event. When the selected edge is detected, the interrupt flag is

set. The flag is cleared by the two-step sequ ence described in Section 9.6.1.

When a channel is configured as an output compare channel, the interrupt flag is set each time the main timer counter matches

the 16-bit value in the channel value register. T he flag is cleared by the two-step sequence described in Section 9.6.1.

9.6.4 PWM End-of-Duty-Cycle Events

For channels that are configured for PWM operation, there are two possibilities:

• When the channel is configured for edge-aligned PWM, the channel flag is set when the timer counter matches the channel

value register that marks the end of the active duty cycle period.

• When the channel is configured for center-a ligned PWM, the timer count matches the channel value register twice during

each PWM cycle. In this CPWM case, the channel flag is set at the start and at the end of the active duty cycle, which are

the times when the timer counter matches the channel value regi ster.

The flag is cleared by the two-step sequence described in Section 9.6.1.

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10 Other MCU Resources

It is not intended that physical parameter measurements be made during the time that LFR may be actively receiving/decoding

LF signals; or during the time that the RFM may be actively powered up and/or transmitting RF data. The resulting interactions

will degrade the accuracy of the measurements.

The FXTH870xD measures six physical parameters for use in the tire pressure monitoring application: pressure, temperature,

battery voltage, two external voltages and an optional X- and/or Z-axis acceleration. Each parameter is accessed in a different

manner and all use firmware subroutine calls as described in Section 14. These subroutines initialize some control bits within the

sensor measurement interface, SMI, and then place the MCU into the STOP4 mode until the measurement is completed with an

interrupt back to the MCU.

The accuracy, power consumption and timing specified for any measurement given in the electrical specifications in Section 17

are only guaranteed if the user obtains a reading using the specified firmware subroutine call in Section 14.

The FXTH870xD uses a 6-channel, 10-bit analog-to-digital converter (ADC10) module. The ADC10 module is an analog-to-digital

converter using a successive approximation register (SAR) architecture with sample and hold. Capture of pressure and

acceleration sensor readings is controlled by the sensor measurement interface (SMI) and capture of temperature and voltage

readings are controlled by the MCU.

When making measurements of the various analog voltages the individual blocks. will first be powered up long enough to stabilize

their outputs before a conversion is started. The ADC channels are connected in hardware. Conversions are started and ended

synchronously with the sampling of the voltages.

The accuracy , power consumption and timing specifications given in the electrical specifications in Section 17 are based on using

the assigned firmware subroutines in Section 14 to make these measurements and convert them into an 8-bit, 9-bit or 10-bit

transfer function. These measurement accuracy specifications cannot be guaranteed if the user creates custom software routines

to convert these measurements.

10.1 Pressure Measurement

The pressure measurement consists of an interface to a pressure sensing element. Control bits on the MCU operate the SMI to

power up the P-Cell and capture a voltage which is converted by the ADC10. The resulting pressure transfer equation for the

100-450 kPa range:

Eqn. 1

The transfer equation of th e 100-900 kPa range is:

Eqn. 2

Due to calibration routines and parameters stored in the FXTH870xD, the pressure range is selected at production and canno t

be changed in the field.

NOTE

Lack of change of the pressure measurement over time may indicate the package pressure

port to be blocked or the internal section of the sensor to be contaminated. User application

should maintain either locally or at the system data receiver a record of pressure

measurements along with temperature and/or accelerometer measur ements, and possibly

identify the pressure port as blocked or contaminated if no changes are recorded over time.

Table 53. ADC10 Channel Assignments

ADC10 Channel Input Select Firmware Call(s) Characteristic

AD0

Pressure Sensor TPMS_READ_COMP_PRESSURE PCODE

Optional X-axis Acceleration Sensor TPMS_READ_COMP_ACCEL_X AXCODE

Optional Z-axis Acceleration Sensor TPMS_READ_COMP_ACCEL_Z AZCODE

AD1 Temperature Sensor TPMS_READ_COMP_TEMP_8 TCODE

AD2 Bandgap Reference TPMS_READ_COMP_VOLTAGE VCODE

AD3 GPIO PTA0 TPMS_READ_V0 G0CODE

AD4 GPIO PTA1 TPMS_READ_V1 G1CODE

AD5 VREG Monitor TPMS_WIRE_CHECK

PP450 PCODE

100 P450

–+=

PP900 PCODE

100 P900

–+=

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10.2 Temperature Measurements

The temperature is measured from a VB sensor built into channel 1 of the ADC10 in the same manner as is done in the

FXTH870xD devices with the resulting transfer equation:

Eqn. 3

10.3 Voltage Measurements

Voltage measurements can be made on the internal bandgap to estimate the supply voltage on VDD.

10.3.1 Internal Bandgap

An internal bandgap voltage reference is provided to take measurements of the supply voltage. The resulting transfer equation:

Eqn. 4

10.3.2 External Voltages

Measurements of an external voltage on either the PTA0 or PTA1 pins can be made and referenced to the internal bandgap

voltage. The resulting transfer equation:

Eqn. 5

where x = 0, 1 refers to PTA0 or PTA1.

10.4 Optional Acceleration Measurements

The acceleration measurement consists of an interface to an optional acceleration sensing element. Control bits on the MCU

operate the SMI to power up the g-Cell and capture a voltage which is converted by the ADC10. The data from the ADC10 is

then pre-processed by a dynamic range firmware routine that will return the two values necessary to calculate the acceleration,

Ay, (y = X-axis or Z-axis, depending on selection) in conjunction with values taken from the table in Section 17.10.1.

The first value from the firmware routine is the offset step identifier, STEP, with integer values 0 to 15 (i .e. the 16 offset steps).

The other value is the ADC10 data, AyCODE, with integer values 0 to 511. AyCODE values 1 through 510 are usable; values 0 and

511 indicate fault conditions. The X-axis acceleration is scaled for ~20g range within each of the 16 offset steps, ~10g per step.

The Z-axis acceleration is scaled for ~80g range within each of the 16 offset steps, ~80g or ~60g. The steps are at ~40g or ~30g

increments, allowing for adequate overlaps. Section 17.10.1 provides a table of acceleration values resulting from

characterizations.

Acceleration sensitivity , Ay-STEP, varies between each offset step, and should be calculated by dividing the range of g’s for each

offset step by the usable AyCODE range (i.e. 510):

Eqn. 6

Once the sensitivity Ay-STEP has been calculated, the acceleration Ay can be calculated by the re-using the Ay-STEP @ AyCODE

1 value of the offset step and the returned AyCODE value with the following transfer functio n:

Eqn. 7

The pressure, and optional X or Z-axis accelerometer also share the same signal path in the Tr ansducer interface and all the

sensors share the same ADC. Therefore only one of the sensors can be accessed at a given moment.

10.5 Optional Battery Condition Check

The condition of the battery can be periodically checked to determine the battery’s internal impedance, RBATT, which is a function

of both temperature and the remaining battery capacity . This can be performed by user supplied software routine and an external

load resistor, RLOAD, connected from the PTA0 pin to VSS as shown in Figure 56 (any of the PTA[3:0] can be used for this

purpose).

NOTE

The included accelerometers are designed with a self-test feature. Consult sales/application

support for information regarding the recommended use of the accelerometer self-test

features.

TTT

CODE 55–=

VINT VINT VCODE 1.22+=

VPTAx VEXT GxCODE

=

Ay-STEP Ay-STEP @ AyCODE510 Ay-STEP @ AyCODE1–510=

AyAy-STEP AyCODE Ay-STEP @ A yCODE1Ay-STEP

–+=

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Figure 56. Battery Check Circuit

The battery voltage can first be checked using the method given in Section 10.3 with the selected PTA0 pin set as an output and

driven low and then high to determine VDD where only IDD flows or when IDD plus ILOAD flows. The resulting battery impedance

can then be calculated as:

Eqn. 8

If it is assumed that IDD0 and IDD1 are not appreciably different at the small change in VDD, then the resulting battery impedance

can be approximated as:

Eqn. 9

where: VDD0 is the voltage determined with the external load resistor connected to VSS

VDD1 is the voltage determined with the external load resistor connected to VDD

RLOAD is the resistance of the external load resistance in ohms

RBATT is the implied battery impedance in ohms

It is recommended that this calculation be performed with a reasonable current load on the battery of approximately 3 mA (RLOAD

approximately 1000 ohms).

PTA0

VSS

VDD

FXTH870xxx

RLOAD +

VBATT

IDD

Port Pin Driven Low Port Pin Driven High

RBATT PTA0

VSS

VDD

FXTH870xxx

RLOAD +

VBATT

IDD + ILOAD RBATT

ILOAD

VDD0 VBATT IDD0 RBATT

–= VDD1 VBATT IDD1 ILOAD

+RBATT

–=

VDD1 VBATT IDD1

VDD1

RLOAD

---------------------







RBATT

–=

RBATT

VDD1 VDD0

–

IDD0 IDD1

–

VDD1

RLOAD

---------------------

---------------------------------------------------------------

RBATT

VDD1 VDD0

–

VDD1

RLOAD

---------------------

--------------------------------------- RLOAD VDD1 VDD0

–

VDD1

-------------------------------------------------------------------------

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10.6 Measurement Firmware

The firmware for making measurements is comprised of two function calls as described in Section 14. Each measurement is a

combination of a “read” that returns the raw ADC output data and a “comp” routine which compensates that raw reading based

on information contained in the Universal Uncompensated Measurement Array (UUMA) assigned in RAM memory.

The read routines fill specific locations in the UUMA with raw data; but the compensation routines depend what is already present

in the UUMA as shown in the data flow in Figure 57.

The user therefore has the option to decide how often each measurement (and its component terms) are made. The resulting

power consumption is then the sum of using these components are defined in the electrical specifications in Section 17.

A typical flow for a compensated pressure measurement would be:

1. Call the TPMS_READ_PRESSURE routine which yields a raw pressure value and fills the UUMA with this data.

2. Call the TPMS_READ_TEMPERATURE routine which yields a raw temperature value and fills the UUMA with this

data.

3. Call the TPMS_READ_VOLTAGE routine which yields a raw voltage value and fills the UUMA with this data.

4. Call the TPMS_COMP_PRESSURE routine which then takes the raw pressure, temperature and voltage values from

the UUMA and compensates to provide a true pressure readi ng to the accuracy as specified in Section 17.

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Figure 57. Data Flow For Measurements

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10.7 Thermal Shutdown

When the package temperature becomes too low or too high the MCU can be placed into a STOP mode to suspend operation

and prevent transmission of RF signals which may be corrupted at the temperature extremes. Return to normal operation after

the temperature falls back within the recovery temperature range. The presence of either the low or high temperature shutdown

will disable the PWU from causing either a periodic wake up or a periodic reset. The MCU, temperature sensor and ADC10 are

all functional over the full temperature range from TL to TH.

10.7.1 Low Temperature Shutdown

Low temperature shutdown is achieved using temperature readings taken by the ADC10 as described in Section 10.2 and

enabling the thermal restart circuit by setting the TRE bit and selecting the low temperature threshold by clearing the TRH bit.

When the software programmed low temperature is reached the MCU will turn off all operating functions and enter the STOP1

mode.

10.7.2 High Temperature Shutdown

The high temperature shutdown level is determined from a measurement of the temperature sensor by the ADC10 as described

in Section 10.2 and enabling the thermal restart circuit by setting the TRE bit and selecting the high temperature threshold by

setting the TRH bit. When the software programmed high temperature is reached the MCU will turn off all operating functions and

enter the STOP1 mode.

10.7.3 Temperature Shutdown Recovery

The MCU can be restarted by the Temperature Restart (TR) module when the temperature returns within the normal temperature

range, TRESET. When this occurs the MCU will be reset and begin execution from the reset vector located at $DFFE/$DFFF. The

TR module can be enabled using the TRE bit in the SIMOPT1 register. The TR module can be powered on and off by setting or

clearing the TRE bit located at bit 3 in the SIMOPT1 register at address $1802. The TRE bit is cleared by an MCU reset.

When the TRE bit is set the TR module can then be set to detect a recovery from either a high temperature or a low temperature

using the TRH in the SIMOPT1 register. Th e TRH bit is cleared by an MCU reset.

The TR module does not activate an MCU restart and reset unless it has first moved outside the re-arming temperature range,

TREARM, as shown in Figure 58. The status of the TR can be checked by reading the TRO bit locate d at bi t 0 in the SIMTST

1 = TR module is outside the TREARM temperature range and will restart the MCU if the TRE bit is set and

temperature falls back within the TRESET temperature range.

0 = TR module is within the TRESET temperature range and the MCU cannot be armed to restart when

temperature falls back to the TRESET range. The TRE bit cannot be set.

Figure 58. Temperature R es tart Response

TRO = 1

TRO = 0

TRESET

TREARM

TRO

TEMPERATURE

SHUTDOWNSHUTDOWN ACTIVE

TREARML TREARMH

TRESETL TRESETH

TRH = 1TRH = 0

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This sequence is further explained by the user software flowchart in Figure 59.

Figure 59. Flowchart for Using TR Module

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11 Periodic Wakeup Timer

The periodic wakeup timer (PWU) generates a periodic interrupt to wakeup the MCU from any of the STOP modes. It also has

an optional periodic reset to restart the MCU. It is driven by the LFO oscillator in the RTI module which generates a clock at a

nominal one millisecond interval. The LFO and the wakeup timer are always active and cannot be powered off by any software

control. The control bits are set so that there is either a periodic wakeup, a periodic reset, or both a wakeup interrupt and a

periodic reset. No combination of control bits will disable both the wakeup interrupt and the periodic reset. In addition, there is no

hardware control that can mask a wakeup interrupt on ce it is generated by the PWU.

11.1 Block Diagram

The block diagram of the wakeup timer is shown in Figure 60. This consists of a programmable prescaler with 64 steps that can

be used to adjust for variations in the value of the LFO period. Finally there are two cascaded programmable 6-bit dividers to set

wakeup and/or reset time intervals.

Figure 60. Wakeup Timer Block Diagram

The wakeup divider (PWUDIV) register selects a division of the incoming 1 ms clock to generate a wakeup clock, WCLK. The

WCLK frequency can be calibrated against the more precise external oscillator using the TPMS_LFOCOL firmware subroutine

as described in Section 14. This subroutine turns on the RFM crystal oscillator and feeds a 500 kHz clock to the TPM1 for one

cycle of the LFO. The measured time is used to calculate the correct value for the WDIV[5:0] bits for a WCLK period of 1 second.

The TPMS_LFOCOL subroutine cannot be used while the RFM is transmitting or the TPM1 is being used for another task.

The wakeup time register (PWUSC0) selects the number of WCLK pulses that are needed to generate a wakeup interrupt to the

MCU. The periodic reset register (PWUSC1) selects the number of wakeup pulses that are needed to generate a periodic reset

of the MCU. Both the wakeup time counter and the periodic reset timer are incrementing counters that generate their interrupt or

reset when the desired count is reached and are then reset to zero. Readin g the status of either of these counters will return a

zero content if done immediately after the interrupt or reset is generated.

If both the reset and the interrupt occur on the same clock cycle the reset will have precedence and the interrupt will not be

generated.

In order to prevent wakeup or reset from an extreme temperature event both the wakeup interrupt or periodic reset are disabled

if the thermal restart is activated and the TRO bit indicates that the device is still outside of the TRESET range. The wakeup and

periodic reset counters will still run. The state of these counters can be read using the PSEL bit in the PWUS register.

The wakeup interrupt (WUKI) cannot be masked by clearing the I-bit.

CONTROL

LOGIC

LFO 6-BIT

WAKEUP

WUF

PROGRAMMBLE

PRESCALER

WDIV[5:0] WUT[5:0]

WUKI

PRST[5:0]

DIVIDER

6-BIT

PERIODIC

RESET

WCLK RCLK

DIVIDER

PRF

PRST

WUFAK

TRO

PRFAK

TRE

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11.2 Wakeup Divider Register - PWUDIV

The PWUDIV register contains six bits to select the division of the incoming 1 ms clock period as described in Figure 61.

11.3 PWU Control/Status Register 0 - PWUCS0

The PWUCS0 register contains six bits to select the division of the incoming WCLK clock period and provide inte rrupt flag and

acknowledge bits as described in Figure 62. The period of the resulting interrupt also generates the clock, RCLK, for the periodic

reset timing.

$0038 Bit 7 654321Bit 0

R0 0 WDIV[5:0]

RESET: ————————

POR: 00011111

= Reserved

Figure 61. PWU Divider Register (PWUDIV)

Table 54. PWUDIV Register Field Descriptions

Field Description

7:6

Unused Unused

5:0

WDIV[5:0]

Wakeup Divider Value — The WDIV[5:0] bits select an incoming prescaler for the incoming 1 ms clock period from 504 to 1512.

This results in a clocking of the 6-bit wakeup divider at rates from a nominal 0.504 to 1.512 sec per wakeup clock, WCLK. The

user can use this prescaler to fine tune the wakeup time based on the variation in the LFO frequency. The conversion from the

decimal value of the WDIV bits to the nominal WCLK period is given as:

A power on reset presets these bits to a value of $1F (decimal 31) which yields a nominal 1 second output period for WCLK.

Other resets have no effect on these bits.

$0039 Bit 7 6 5 4 3 2 1 Bit 0

RWUF 0WUT[5:0]

WWUFAK

RESET: 0—111111

Figure 62. PWU Control/Status Register 0 (PWUCS0)

Table 55. PWUSC0 Register Field Descriptions

Field Description

WUF

Wakeup Interrupt Flag — The WUF bit indicates when a wakeup interrupt has been generated by the PWU. This bit is cleared

by writing a one to the WUFAK bit. Writing a zero to this bit has no effect. Reset clears this bit.

0 Wakeup interrupt not generated or was previously acknowledged.

1 Wakeup interrupt generated.

WUFAK

Acknowledge WUF Interrupt Flag — The WUFAK bit clears the WUF bit if written with a one. Writing a zero to the WUFAK bit

has no effect on the WUF bit. Reading the WUFAK bit returns a zero. Reset has no effect on this bit.

0 No effect.

1 Clear WUF bit.

tWCLK 504 16 WDIV+

fLFO

-------------------------------------------------

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11.4 PWU Control/Status Register 1 - PWUCS1

The PWUSC1 register contains six bits to select the division of the incoming RCLK clock perio d and provide interrupt flag and

acknowledge bits as described in Figure 63.

5:0

WUT[5:0]

WUF Time Interval — These control bits select the number of WCLK clocks that are needed before the next wakeup interrupt

is generated. The count gives a range of wakeup times from 1 to 63 WCLK clocks.

Depending on the value of the bits for the WDIV[5:0] this time interval can nominally be from 1 to 63 seconds in 1 second steps.

Whenever the WUT[5:0] bits are changed the timeout period is restarted. Writing the same data to the WUT[5:0] bits has no

effect.

Writing zeros to all of the WUT[5:0] bits forces the wakeup divider to a value of $3F and disables the wakeup interrupt. However,

writing all zeros to the WUT[5:0] bits is inhibited if all of the PRST[5:0] bits are already cleared to zero. This prevents disabling

both the periodic wakeup and the periodic reset at the same time. See Table 56.

The WUT[5:0] bits are preset to a value of $3F (decimal 63) by any resets.

Table 56. Limi tations on Clear ing WUT/PRST

Control Bits State of Control Bits Control Bits to be

Cleared Resulting Action Resulting Wakeup

Interrupt Resulting Periodic

Reset

WUT[5:0] non-zero PRST[5:0] Allowed Enabled(1)

1. Using previous values.

Disabled

all zero Inhibited Disabled(2)

2. Wakeup divider preset to $3F.

Enabled(1)

PRST[5:0] non-zero WUT[5:0] Allowed Disabled Enabled(1)

all zero Inhibited Enabled(1) Disabled

$003A Bit 7 6 5 4 3 2 1 Bit 0

RPRF 0PRST[5:0]

WPRFAK

RESET: 00111111

= Reserved

Figure 63. PWU Control/Status Register 1 (PWUCS1)

Table 57. PWUSC1 Register Field Descriptions

Field Description

PRF

Periodic Reset Flag — The PRF bit indicates when a periodic reset has been generated by the PWU. MCU writes to this bit

have no effect. This bit is cleared by writing a one to the PRF AK bit. This bit is cleared by a power on reset, but is unaffected by

other resets.

0 Periodic reset not generated or previously acknowledged.

1 Periodic reset generated.

PRFAK

Acknowledge PRF Interrupt Flag — The PRFAK bit clears the PRF bit if written with a one. Writing a zero to the PRFAK bit

has no effect on the PRF bit. Reading the PRFAK bit returns a zero. Reset has no effect on this bit.

0 No effect.

1 Clear PRF bit.

5:0

PRST[5:0]

Periodic Reset Time Interval — These control bits select the number of wakeup interrupts that are needed before the next

periodic reset is generated. The decimal count gives a range of periodic reset times from 1 to 63 wakeup interrupts. Depending

on the value of the bits for the WDIV[5:0] and WUT[5:0] this time interval can nominally be from 1 second to 66 minutes with

steps from 1 to 63 seconds. Whenever the PRST[5:0] bits are changed the timeout period is restarted. Writing the same data to

the PRST[5:0] bits has no effect.

Writing zeros to all of the PRST[5:0] bits forces the periodic reset to be disabled if at least one of the WUT[5:0] bits is set to a

one. This assures that there will be at least a wakeup interrupt. However, writing all zeros to the PRST[5:0] bits is inhibited if all

of the WUT[5:0] bits are already cleared to zero. This prevents disabling both the periodic wakeup and the periodic reset at the

same time. See Table 56. The PRST[5:0] bits are preset to a value of 63 by any resets.

Table 55. PWUSC0 Register Field Descriptions (continu e d)

Field Description

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11.5 PWU Wakeup Status Register - PWUS

The PWUS register shows the current status of the two PWU counters as described in Figure 63. The counter conten ts are

captured when the register is read.

11.6 Functional Modes

PWU module will work in each of the MCU operating modes as follows:

11.6.1 RUN Mode

If the module generates a wakeup interrupt the PC (Program Counter) will be redirected to the wakeup timer interrupt vector . The

WUF flag will be set to indicate wakeup timer interrupt; write 1 to WUFACK to clear this flag.

If the module genera tes a reset the PC will be redirected to the reset vector. The PRF flag will be set to indicate periodic reset;

write 1 to PRFACK to clear this flag.

All registers will continue to hold th eir programmed values after interrupt or reset is taken.

11.6.2 STOP4 Mode

If the module generates a wakeup interrupt the bus and core clocks will be restarted and the PC will be redirected to the wakeup

timer interrupt vector. The WUF flag will be set to indicate wakeup timer interrupt, write 1 to WUFACK to clear this flag.

If the module generates a periodic reset the bus and core clocks will be restarted and the PC will be redirected to the reset vector.

The PRF flag will be set to ind icate periodic reset; write 1 to PRFACK to clear this flag.

All registers will continue to hold th eir programmed values after interrupt or reset is taken.

11.6.3 STOP1 Mode

If the module generates a wakeup interrupt the module will cause the MCU to exit the power saving mode as a POR. MCU will

have the wakeup interrupt pending and once CLI op code is executed PC will be redirected to wakeup interrupt ve ctor address.

The WUF flag will be set to indicate wakeup timer interrupt, write 1 to WUFACK to clear this flag.

If the module generates a periodic reset the module will cause the MCU to exit the power saving mode as a POR. The PRF flag

will be set to indicate periodic reset; write 1 to PRFACK to clear this flag. The SRS register will have just the POR bit set.

In this STOP mode exit all registers will continue to hold their programmed values.

11.6.4 Active BDM/Foreground Commands

The PWU is frozen in ACTIVE BACKGROUND mode or executing foreground commands, so PWU counters will also be stopped.

Normal PWU operation will resume as MCU exits BDM or foreground command is finished.

$001F Bit 7 6 5 4 3 2 1 Bit 0

RPSEL 0CSTAT

RESET: 0-------

= Reserved

Figure 64. PWU Wakeup Sta tus Regi ster (PWU S)

Table 58. PWUS Register Field Descriptions

Field Description

PSEL

Page Selection — The PSEL read/write bit selects whether the other bits are read from the WUT or PRST counters. This bit is

cleared by a power on reset that is not created by an exit from the STOP mode, but is unaffected by other resets.

0 CSTAT = WUT counter status

1 CSTAT = PRST counter status

unused Unused — An unused bit that always reads as a logical zero.

5:0

CSTAT

Counter Status — These read-only bits show the status of the counter selected by the PSEL bit. The effects of any reset on

these bits depends on how the reset affects the selected counter. Reading these counters immediately after a WUF or PRF

generated flag will return zero contents.

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12 LF Receiver

The low-frequency receiver (LFR) is a very low-power, low-frequency, receiver system for short-range communication in TPMS.

The module allows an external coil to be connected to two dedicated differential input pins. In TPMS systems a single coil may

be oriented for optimal coupling between the receiver in the tire or wheel and a transmitter coil on the vehicle body or chassis.

This LFR system minimizes power consumption by allowing flexibility in choosing the ratio of on to off times and by turning off

power to blocks of circuitry until they are needed during signal reception and protocol recognition. In addition, this LFR system

can autonomously listen for valid LF signals, check for protocol and ID information so the main MCU can remain in a very low

power standby mode until valid message data has been received.

The LFR can be configured for various message protocols and telegrams to allow it to be used in a broad range of applications.

The message preamble must be a series of Manchester coded bits at the nominal 3.906-kbps data rate. A synchronization pattern

is used to mark the boundary between the preamble and the beginning of Manchester encoded information in the message body .

The synchronization pattern is a non-Manchester specific TPMS pattern. Messages can optionally include none, an 8-bit or a 16-

bit ID value. Messages may contain any number of data bytes with the end-of-message indicated by detecting an illegal

Manchester bit at a data byte boundary.

It is not intended that LFR may be actively receiving/decoding LF signals while physical parameter measurements are being

made; or during the time that the RFM may be actively powered up and/or transmitting RF da ta. The resulting interacti ons will

degrade the accuracy of the LF detection.

Figure 65. Block Diagram

For definitions of the acronyms and de tailed descri ptions of the bits and/or byte registers, please refer to Section 12.17.

Rectifier3

Data

Slicer

1kHz_clock

Carrier

Detector

MFO

32kHz

Clamp

LFA

LFB

1 kHz_clock Typ

129 kHz

Ty p

Clamp Rectifier0 Rectifier1 Rectifier2

Amp1

Sensitivity

Buff1 Amp3Amp2 Buff3

Buff2

Vref_sensitivity

Carrier

Detector

Logic Block 1:

- On/Off cycling

- Carrier Detection

Logic Block 2:

- Data decoding

Data

Slicer

Average

Filter

Summator

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92 Freescale Semiconductor, Inc.

12.1 Features

Major features of the LFR module include:

• Differential input LF detector (two dedicated pins):

— Selectable sensitivity (two levels: Low Sens (LS) and High Sens (HS)).

— Thresholds trimmed at the factory with trim setting saved in nonvolatile memory.

— LFR has a reference oscillator (LFRO) trimmed at the factory with trim setting saved in nonvolatile memory.

— Selectable signal sampling time interval and on-time.

— Sample interval and on times controlled by LFR state machine or directly by the MCU.

• Configurable receive mode:

— Simple LF carrier detection/Telegram decode. (CARMOD)

• Configurable message protocol (telegram structure):

— Various SYNC decoding (SYNC[1:0])

6-bit time SYNC requirements

7.5-bit time SYNC requirements

9-bit time SYNC requirements

— Optional ID (ID[1:0])

8-bit or 16-bit ID

On or off

— 0-n bytes of message data. End-of-data marked by loss of Manchester at a byte boundary.

• Optional continuous monitoring and decode of the LF detector.

• Selectable MCU interrupt when a received data byte is ready in an LFR buffer, when a Manchester error is detected in the

frame, when an ID is received or when a valid carrier has been detected.

12.2 Modes of Operation

The LFR is a peripheral module on an MCU. After being configured by application software, the LFR can operate autonomously

to detect and verify incoming LF messages. When a valid message or carrier pulse is received and verified the LFR can wake

the MCU from standby modes to read received data or act upon a carrier detection.

The primary modes of operation for the LFR are:

• Disabled. Everything off and drawing minimal leakage current. LFR register contents will be retained.

• Carrier detect/listen. Minimum circuitry enabled to detect any incoming LF signal, check it for the appropriate signal level,

frequency and duration.

• TPMS protocol verification.

• Data reception.

12.3 Power Management

In addition to using low power circuit design techniques, the LFR module provides system-level features to minimize system

energy requirements. In an MCU that includes the LFR module, all MCU circuitry except a very low current 1-kHz oscillator (LFO)

and minimum regulator circuitry can be disable d. After a reset, the MCU would initia lize the LFR module and then enter a very

low power standby mode (depending upon the MCU, this could be lower than 1 uA for the MCU portion). The LF R module

includes everything it needs to periodically listen for LF messages, perform Manchester decoding, verify the message telegram,

and assemble incoming data into 8-bit bytes. The LFR does not wake the MCU unless a valid message is being received and a

data byte is ready to be read.

The LFR cycles between an off state, where everything is disabled, and an on state, where it listens for a carrier signal. The on

time is controlled by LFONTM[3:0] control bits in the LFCTL2 register. The time between the start of each sample on time is

controlled by LFSTM[3:0] control bits in the LFCTL2 register . Even lower duty cycles can be achieved by using the MCU to wake

once per second and maintain a software counter to delay for an arbitrarily long time before enabling the LFR to perform a series

of carrier detect cycles.

Within the LFR, circuits remain disabled until they are needed. When the LFR is listening for a carrier signal, only a 1-kHz clock

source, a portion of the input amplifier and a periodic auto-zero are running. After a carrier signal is detected, with high enough

amplitude, frequency and duration the LFRO oscillator is enabled so the LFR can begin to decode the incoming information.

The LFR module has a power up settling time of 2-LFO period before any active operations. In the ON/OFF cycle, those 2 ms

are hidden in the sampling time during the off time.

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Freescale Semiconductor, Inc. 93

12.4 Input Amplifier

The LFR module receives LF modulated signals through a dedicated differential pair of inputs which is connected to an external

coil. The enable control (LFEN) allows the user to enable the LF input depending on the application requirements. The SENS[1:0]

bits in the LFCTL1 register allows the user to select one of two input sensitivity thresholds which determines the signal level

required before the input carrier will be detected. The sensitivity settin g is used during carrier detection but does not affect

reception after the carrier has been detected. When the CARMOD bit is cleared, after a carrier with sufficient amplitude,

frequency and duration has been detected the output stage of the amplifier is turned on to allow data reception.

12.5 LFR Data Mode States

The modes of operation the LFR state machine will sequence as shown in Figure 66.

12.6 Carrier Detect

Carrier detection includes a check for a certain number of ed ges on a sign al that is greater than the input sensitivity threshold.

During the check for carrier edges, only the 1kHz low frequency oscillator (LFO) clock source is running so power consumption

remains very low.

During carrier detection the incoming signal is amplified and passed through a sensitivity threshold comparator. The SENS[1:0]

bits in the LFCTL1 register selects two levels of sensitivity and determines the signal amplitude that is needed to allow edges to

be seen at the output of the sensitivity threshold comparator. When a carrier is above this threshold, a block is powered on and

validates the carrier . This frequency and duration check function can be disabled by clearing the VALEN bit. If VALEN is set, the

block checks for the carrier duration and the carrier frequency. The time needed to validate a carrier is programmed by th e

LFCDTM register. The carrier frequency should be 125 kHz. If the signal ab ove the threshold is not within the frequency range

or not present during enough time, then the carrier will not be validated and the validation block will turn off.

If no carrier signal is validated within the on time of the LFR, the state machine returns to the off state and the alternating cycle

of on time and off time continues. Carrier edge counts start at zero when a new on time begi ns.

In the data mode (CARMOD=0), if the required number of carrier edges are detected before the end of the ON time, the LFR will

remain ON to complete the reception of a message telegram.

In the carrier detect mode (CARMOD=1) there is no need to enable other LFR circuitry to evaluate any other message

components after the required number of carrier edges are detected. One or several consecutive carriers can be validated by

this process before the LFCDF flag is set. The LFCC control bits are used to program the number of consecutive ON times where

a complete carrier validation is needed before interrupting the MCU. In this case, the LFCDF flag is set and, provided the LFCDIE

interrupt enable is also set, an interrupt is issued to wake the MCU. In carrier detect mode, the LFCDIE control bit should always

be set because the intended purpose of the carrier detect mode is to wake the MCU when a carrier is detected. When LFCDF is

set, the LFR waits until it is cleared before it continues the alternating cycle of on time and off time, starting with an off time.

In data mode, when a carrier is detected the averaging filter is powered on and the LFR continues to the next state to look for the

rest of a message telegram; and the LFR modu le will search for valid SYNC word (with length programmed throug h the SYNC

bits in the LFCTL3 register depending on preamble type). If the external LF field is not a TPMS frame, a timeout will turn off the

LFR module. Thi s ti me out can be program through TIMOUT bit the LFCTL4 register.

FXTH870xD

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94 Freescale Semiconductor, Inc.

Figure 66. FXTH870xD LFR State Machine Diagram

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FXTH870xD

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Freescale Semiconductor, Inc. 95

12.7 Auto-Zero Sequence

An auto-zero sequence is performed periodically on the input amplifie r to cancel offset errors. During reception of the SYNC

pattern and body of the message, auto-zero operations are synchronized to data edges of the incoming signal to avoid interfering

with normal reception. During the auto-zero sequence, the input amplifier is temporarily disconnected from the external coil and

connected to ground. The auto-zero sequence takes roughly 64 sec. It is performed at each LFO period in carrier mode and on

one over four decoded data edges in data mode.

When the DECEN bit is cleared, the auto-zero sequence is performed at each LFO period. During the 64 sec of the auto-zero

sequence, the receiver is holding the state “0” or “1”' previously decoded. Since the LFR receiver is not active during this time,

the possible data-rate that the analog can detect is at least limited by this duration.

12.8 Data Recovery

Rectified signals from the amplifier output are conn ected to the input of an averaging filter and data slicer. The slicer thus

compares the rectified signal with its own average value to decode the data . When a carri er is presen t, the slic er outpu t volt age

rises and when the carrier stops the slicer output voltage falls. The output of this comparator provides a binary digital signal that

indicates whether the carrier is present or not. This digital signal is connected to the data clock recovery circuit, the SYNC detect

circuit, and the Manchester decoder circuit.

The Manchester decoder uses the digital output of the data slicer to detect the logic level of each incoming data bit and to

synchronize the decoder state machine. The LFPOL polarity bit in the LFCTRLA register selects the expected encoding of the

Manchester data bit.

If a strong signal (above roughly 100 mV p-p differential) is entered into the LFR, the input impedance will switch instantaneously

to a lower programmed value (the LOWQ[1:0] bits in the LFCTRLC) and be maintained during the current data packet if the

DEQEN bit is set. At the next ON time, the default high input impedance will be set again. The strong signal detection and the

automatic impedance change can be disabled by clearing the DEQEN bit.

12.9 Data Clock Recovery and Synchronization

Data clock recovery and synchronization takes place during the SYNC portion of an incoming message. The preamble must be

modulated Manchester data. The type of required SYNC pattern determines the allowed preamble type depending on the

SYNC[1:0] control bits.

The design data rate is 3.906 kbps which gives a bit time equivalent to about 32 cycles of the LF carrier frequency. In a

Manchester encoded bit time, the carrier should be present for either the first half or the second half of the bit time depending on

whether the bit is a logic zero or a logic one.

The LFRO clock source is 32 times the target data rate. The LFRO is used for decoding data and also sequencing auto-zero

operations.

12.10 Manchester Decode

When the LFPOL bit is clear, a logic one bi t is defined as no LF carrier present for the first half of the bit time; and a logic zero

bit is defined as LF carrier present for the first half of the bit time as shown in Figure 67. Another way to say this from the point

of view of the data slicer output is that a logic zero bit has a falling edge at the middle of the bit time and a logic one bit has a

rising edge at the middle of the bit time. The data slicer threshold is dynamically adjusted to the midpoint between the carrier-

present and no-carrier levels at the summing node for the rectified output of the LF input amplifier.

FXTH870xD

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96 Freescale Semiconductor, Inc.

Figure 67. Manche ster Encoded Datagram for LFPO L = 0

When the LFPOL bit is set, a logic one bit is defined as LF carrier present for the first half of the bit time; and a logic zero bit is

defined as no LF carrier present for the first half of the bit time as shown in Figure 68.

Figure 68. Manche ster Encoded Datagram for LFPO L = 1

12.11 Duty-Cycle For Data Mode

The definition of the duty-cycle for the Manchester encoded data depends on the relative rise and fall times of the incoming LF

carrier as shown in Figure 69.

Figure 69. Definition of Duty -Cycle of 40%

Regarding the SYNC pattern which is non-Manchester coded, the duty cycle is applied on all falling edges with the same

proportion as a 1T Manche ster symbol, as shown in Figure 70.

0.5T

LF Input

Logic “1” Logic “0”

Data Bit

Data Slicer Threshold

(shaded area

is LF

carrier)

(data slicer

output) T = 1 Bit Time at the data rate (ex. 256 us at data rate of 3.906 kbps)

0.5T

LF Input

Logic “0” Logic “1”

Data Bit

Data Slicer Threshold

(shaded area

is LF

carrier)

(data slicer

output) T = 1 Bit Time at the data rate (ex. 256 s at data rate of 3.906 kbps)

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Figure 70. Impact of Duty-Cycle on SYNC Pattern

12.12 Input Signal Envelope

The combinati on of the external LF antenna and any external components as shown in Figure 71 should not significantly filter

the envelope of the LF carrier as shown in Figure 72. Exce ssive filtering will cause the received message error rate (MER) to

increase.

Figure 71. Antenna Q-factor Equivalent Model for the LF Envelope

Figure 72. LF Envelope Filt ering

LFA

LFB

SUZUKAAnt enna m odel

•Antenna Q- fac tor act s as a 1st order

low pass filter on the L F envelop

• Filter time constant : t= R.C

Recommended< 15.3 sec

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12.13 Telegram Verification

The LFR has control bits to allow flexibility in the telegram format and protocol to allow the LFR to adapt to a variety of systems.

The LFR can operate in a normal data receive mode where it receives complete telegrams, or in a carrier detect mode where it

only checks for a carrier. In the carrier detect mode, as soon as a carrier is detected, the LFCDF flag is set. If LFCDIE is also set,

an interrupt request is sent to wake the MCU

The format of the complete Manchester encoded datagram is comprised of a Manchester data preamble (series of Manchester

1’s or 0’s), a synchron ization period, an optional ID, and zero to n data bytes.

The synchroniza tion period can be used for synchronizing the beginning of the data packet. The SYNC pattern that follows the

preamble can be either a 6-, 7.5- or 9 bit-time no n-Manchester pattern as shown in Figure 73.

Figure 73. SYNC Patterns

These patterns would normally not appear anywhere in the Manchester encoded portion of a message so there is no possibility

that the LFR could accidentally synchronize to a message that was alrea dy in progre ss when the LFR started listening for a

message. These patterns are also complex enough so that it is very unlikely that noise or interference could be mistaken for these

SYNC patterns. In the data mode an d after the detection of a vali d carri er, the LFR will deco de th e da ta stream waiting for the

SYNC word. Should this carrier not be an accepted TPMS type, no SYNC will be received and the LFR module will stay in data

receive mode forever. A timeout counter is thus started after a ca rrier detection an d will stop the receiver if reaching the

programmed value selected by the TIMOUT[1:0] bits in the LFCTL4 register. This timeout counter is clocked by the internal LFRO

clock.

The LFR can be configured to have an optional 0, 8-bit or 16-bit ID after the SYNC pattern. If the ID value matches the received

ID, the message is accepted. The ID value can be used to identif y a specific rece iver, a message type, or some other identifier

as defined by application software.

Any number of data bytes can be included after the ID. The LFR begins to assemble data bytes from the incoming signal as soon

as the ID check is complete. If the first bit-time after the last bit of the ID does not conform to Manchester coding requirements,

the LFR considers the message complete and terminates the LFR operation without setting the data ready flag (LFDRF). If data

follows the ID, it is serially received and when 8 bits have been received the LFR copies this byte into the LFDATA register and

sets the LFDRF flag. If the LFDRIE interrupt enable is also set (and it should be ), an interrupt request is sent to wake the MCU

so it can read the data and process it according to the instructions in the application program. Additional bytes are received until

a bit time that is not Manchester encoded is found. If a non-Manchester bit time is found, the LFERF bit will be set and indicates

a Manchester coding error. If this happens on the first bit of the next byte of the message the LFEOMF bit will also be set.

The preamble is a period of Manchester bits before the SYNC pattern as shown in Figure 74. The SYNC pattern will only be

matched for the bit times specified by the SYNC[1:0] control bits. Depending on the expected SYNC pattern the allowed

preambles is as described for the SYNC[1:0] bits in the LFCTL3 register.

2T 2T

1.5T T

2T 2T

1.5T

3T T

2T 2T

6-bit

(6T)

Pattern

7.5-bit

(7.5T)

Pattern

9-bit

(9T)

Pattern

SYNC[1:0] = 01

SYNC[1:0] = 10

SYNC[1:0] = 11

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Figure 74. Telegram For mat (Carrier Preamble)

12.14 Error Detection and Handling

When the DECEN bit is set, LFR messages are monitored for data rate or SYNC errors, incorrect message ID, and Manchester

coding errors. When an error is detected the LFR goes back to sniff mode until the end of ON time completion, if ONMODE is

set; or turns off until the start of the next scheduled sampling interval, if ONMODE is cleared. Because the MCU uses more power

than the LFR module, it is desirable to keep the MCU in low power standby modes as much as possible. Therefore the handling

of these errors will be performed by the LFR and not require additional software processing by the MCU.

When the DECEN bit is clear , there is no monitoring on data. The MCU needs to poll the state of the LFDO bit and create its own

decoding scheme within software on the detected signal. To be able to start the polling only when data are received, the carrier

detection flag is enabled in data mode when DECEN = 0. During data reception, the auto-zero sequence is performed at each

LFO period. The MCU needs also to determine the end of the telegram and turn off the LFR (LFEN = 0) during two LFO cycles

before any other operations.

12.15 Continuous ON Mode

In the Continuously ON mode, the LFR module will remain on continuously while the LFEN bit is set. The Continuously ON mode

is controlled by setting the LFSTM[3:0] bits.

In the Continuously ON mode, if a signal is successfully processed by the digital, the LFR module will stop and restart

automatically. The gap is 2-3 LFO periods. Also if TOGMOD bit is set, the LFR module will stop after the ON time cycle and re-

start automatically, after having changed the CARMOD bit.

12.16 In itialization Information

When power is applied to the MCU, the LFR must be initialized and configured before it can begin to receive LF messages.

Several systems in the LFR require factory trimming to ensure operation within specified limits. After these trim values are written,

they remain constant until the next MCU reset.

The application program must set up control bits and registers to configure the LFR to dete rmine the structure of the message

telegram, the input sensi tivity, and other LFR options. It is good practice to clear the flags in the LFS register before enabling

interrupt sources in order to avoid any immediate interrupt requests.

PREAMBLE SYNC HIGH ID DATA DATA

6, 7.5 or 9T 0, 8T or 16T 8T

tLFPRE IDSEL[1:0] Repeat for 0-n bytes

LOW ID

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12.17 LFR Register Definition

The LFR module uses eight addresses in the MCU memory map for data, control, and status registers.This section consists of

register descriptions. Each control register (LFCTLx) should be modify when the LF i s of f (LFEN = 0). Modificati on of th e control

registers “on-the-fly” might lead to unknown state. Each turn off of the LFR (LFEN = 0) should be followed by at least two LFO

cycles before trying to restart the LFR (LFEN = 1).

12.17.1 LF Control Register 1 (LFCTL1)

LFCTL1 contains the main LF enable control, detection protocol format controls, and input sensitivity controls. The LFCTL 1

$0020 Bit 7 6 5 4 3 2 1 Bit 0

RLFEN 0CARMOD LPAGE IDSEL[1:0] SENS[1:0]

WSRES

Reset: 00000000

Figure 75. LFR Control Register 1 (LF C TL1 )

Table 59. LFCTL1 Register Field Descriptions

Field Description

LFEN

LF Enable — This read-write control bit is used to enable or disable the LF receiver . Once this bit is set the LFR will go through

a power-up sequence that starts on the next rising edge of the LFO clock. The first complete cycle of the LFO is used to power

up the LFR circuits. Following this startup time the auto-zero sequence is performed for 64sec and then the LFR is ready to

receive signals.

0 LF receiver in standby.

1 LF receiver active.

Note: Enabling the LF receiver function disables the GPIO Port B functions - see Section 6.5.

SRES

Soft Reset — This read/write bit controls the soft reset of the LFR. The bit is self reset and always reads as a logical zero.

0 Reset completed

1 Start a soft reset.

CARMOD

Carrier Mode — This read/write control bit selects the basic operating mode for the LFR.

0 Data receive mode.

1 Carrier detect mode - wake the MCU when a carrier signal is detected if LFCDIE is set.

LPAGE

LFR Page Select — This read/write bit is used is used to select the register page access. The LPAGE bit has no effect on the

LFCTL1 and LFCTL2 registers. This bit is cleared by LFR reset.

0 Access page 0.

1 Access page 1.

3:2

IDSEL[1:0]

Wakeup ID Selection — Selects the existence and length of the wakeup ID. Reset clears these bits.

00 No ID expected

01 8-bit ID based on the contents of the LFIDL register

10 16-bit ID based on the contents of the LFIDH and LFIDL registers

11 8-bit ID matches the contents of either the LFIDH or LFIDL registers

1:0

SENS[1:0]

Sensitivity Control — These two read/write control bits select the sensitivity thresholds for the LFR input. These thresholds

apply to the detection portion of a message. If the input level is below the SNODET_x level, no signal will be detected. If the level

is above SDET_x, the signal will be detected. Sensitivity settings are only used in the carrier detect path and do not affect reception

of the message body.

00 Performance not specified.

01 Low sensitivity (SDET_L; SNODET_L)

10 High sensitivity (SDET_H; SNODET_H)

11 Performance not specified.

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12.17.2 LF Control Register 2 (LFCTL2)

LFCTL2 contains the selection bits for the length of the LF sampling ON time and the time interval between samples as shown

in Figure 76.

$0021 Bit 7 6 5 4 3 2 1 Bit 0

RLFSTM[3:0] LFONTM[3:0]

Reset: 01100000

Figure 76. LFR Control Register 2 (LF C TL2 )

Table 60. LFCTL2 Register Field Descriptions

Field Description

7:4

LFSTM

[3:0]

LF Sampling Time Interval Select— These read/write control bits select the length of time between when the LFR input detector

is turned on as set by the LFONTM bits in LFCTL2 register. The initial sampling interval starts with the LFO clock following a write

to these bits. A reset of the LFR results in the value being set to binary 0110.

0000 Continuous ON mode (see Section 12.15)

0001 Sampled decoding mode every 16 LFO clock periods (16 milliseconds nominal)

0010 Sampled decoding mode every 32 LFO clock periods (32 milliseconds nominal)

0011 Sampled decoding mode every 64 LFO clock periods (64 milliseconds nominal)

0100 Sampled decoding mode every 128 LFO clock periods (128 milliseconds nominal)

0101 Sampled decoding mode every 256 LFO clock periods (256 millisecond nominal)

0110 Sampled decoding mode every 512 LFO clock periods (512 milliseconds nominal)

0111 Sampled decoding mode every 1024 LFO clock periods (1024 milliseconds nominal)

1000 Sampled decoding mode every 2048 LFO clock periods (2 048 milliseconds nominal)

1001 Sampled decoding mode every 4096 LFO clock periods (4 096 milliseconds nominal)

1010-1xxxContinuous ON mode (see Section 12.15)

3:0

LFONTM

[3:0]

LF Sampling ON Time Select — These read/write control bits select the length of time that the LFR input

detector is turned on at the beginning of each sampling interval set by the LFSTM bits. This ON time is the net sampling time

with any initialization time (maximum of 2 ms) included in the OFF time prior to the sample ON time (see Figure 77). If a signal

is successfully detected, the length of time the detector remains ON depends on the operating mode. In carrier detect mode

(CARMOD=1) the detector will be turned off early if the evaluation of the carrier signal is completed before the end of the

scheduled ON time. In data receive mode (CARMOD=0) the detector will remain ON until the end of the message, an error is

detected or timeout occurrence. Reset forces the LFONTM bits to 0:0:0.

0000 1 LFO clock cycle (1 millisecond nominal)

0001 2 LFO clock cycle (2 milliseconds nominal)

0010 4 LFO clock cycle (4 milliseconds nominal)

0011 8 LFO clock cycle (8 milliseconds nominal)

0100 16 LFO clock cycle (16 milliseconds nominal)

0101 32 LFO clock cycle (32 milliseconds nominal)

0110 64 LFO clock cycle (64 milliseconds nominal)

0111 128 LFO clock cycle (128 milliseconds nominal)

1000 256 LFO clock cycle (256 milliseconds nominal)

1001 512 LFO clock cycle (512 milliseconds nominal)

1010 1024 LFO clock cycles (1024 milliseconds nominal)

1011 1024 LFO clock cycles (1024 milliseconds nominal)

11xx 1024 LFO clock cycles (1024 milliseconds nominal)

Note: The LFONTM selected time must be less than the LFSTM selected time, otherwise the Continuously ON mode is present.

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Figure 77. LF Detector Sampling Timing

12.17.3 LF Control Register 3 (LFCTL3)

LFCTL3 contains the control bits for the LF sampling interval and the minimum required carrier detection time when using the

carrier detect mode.

$0022 Bit 7 6 5 4 3 2 1 Bit 0

RLFDO TOGMOD SYNC[1:0] LFCDTM[3:0]

Reset: —0010000

= Reserved

Figure 78. LFR Control Register 3 (LF C TL3 )

Table 61. LFCTL3 Register Field Descriptions

Field Description

LFDO

LF Detector Output — This read-only bit follows the bit slicer output signal that goes high during the presence of a carrier. It

may change at any time. This bit is read only and unaffected by any reset.

0 LF detector output low (no signal above threshold)

1 LF detector output high (received signal above threshold)

TOGMOD

LFR Mode Toggle — This read/write bit enables the toggling of the CARMOD bit at each new LFON sequence. Reset clears

this bit.

0 CARMOD bit does not change and determines detector mode.

1 CARMOD bit will be toggled every LFON detection sequence, starting by CARMOD selection.

Therefore the reception chain will alternately look for a carrier frame or for a data frame.

5:4

SYNC[1:0]

LF SYNC Selection — Selects the type of SYNC pattern as described in Figure 73. Reset presets these bits to the 01 (6T SYNC)

option. Compatible with preamble consisting of minimum 2 ms Manchester data to allow for proper averaging filter operation.

00 For factory test purposes, not intended for use in any application.

01 6T SYNC pattern

10 7.5T SYNC pattern

11 9T SYNC pattern

LFR Detector Active

LFONTM

LFSTM

Power Up

Settling Time Power Up

Settling Time

LFONTM

time segments not to scale

tDEC

LF searching for

SYNC pattern

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The auto-zero sequence needs to be performed every 1 ms. Therefore LFR detection times of 1024, 2048, 4096 and 8192 sec

the auto-zero sequence will be done at each 1 ms interval. This auto-zero sequence lasts for 64 sec. If the carrier is detected

again at the end of the auto-zero sequence it is assumed that the carrier was there for the complete 64 sec period of the auto-

zero.

3:0

LFCDTM

[3:0]

LF Carrier Detect Time — These read/write control bits select the length of time which the LFR input detector must detect a

carrier before validating it. In carrier mode (CARMOD=1), if the carrier is active for at least the time selected by the LFCDTM[3:0]

bits and the LFCC counter value is reached, the LFCDF flag in the LFS register will be set; and if the LFCDIE control bit is also

set, the MCU will be interrupted (wakeup).

In the data receive mode (CARMOD=0) the LFCDTM[3:0] bits select the length of time which the LFR input detector must detect

a carrier before the effective receive chain is powered on. Once the carrier has been validated t he LFCDTM[3:0] bits ignored

during the decode of the rest of the data.

Reset of the LFR results in LFCDTM[3:0] being reset to 0:0:0:0. The resulting carrier detect times are defined by the following

number of carrier periods needed to validate the carrier, with the corresponding time for a carrier at 125 kHz in parenthesis:

0000 Carrier detect = 8 (64 sec)Data mode detect = 8 (64 sec)

0001 Carrier detect = 16 (128 sec)Data mode detect = 8 (64 sec)

0010 Carrier detect = 32 (256 sec)Data mode detect = 8 (64 sec)

0011 Carrier detect = 64 (512 sec)Data mode detect = 8 (64 sec)

0100 Carrier detect = 128 (1024 sec)Data mode detect = 8 (64 sec)

0101 Carrier detect = 256 (2048 sec)Data mode detect = 8 (64 sec)

0110 Carrier detect = 512 (4096 sec)Data mode detect = 8 (64 sec)

0111 Carrier detect = 1024 (8192 sec)Data mode detect = 8 (64 sec)

1000 Carrier detect = 8 (64 sec)Data mode detect = 8 (64 sec)

1001 Carrier detect = 16 (128 sec)Data mode detect = 16 (128 sec)

1010 Carrier detect = 32 (256 sec)Data mode detect = 32 (256 sec)

1011 Carrier detect = 64 (512 sec)Data mode detect = 64 (512 sec)

1100 Carrier detect = 128 (1024 sec)Data mode detect = 128 (1024 sec) (see note)

1101 Carrier detect = 256 (2048 sec)Data mode detect = 256 (2048 sec) (see note)

1110 Carrier detect = 512 (4096 sec)Data mode detect = 512 (4096 sec) (see note)

1111 Carrier detect = 1024 (8192 sec)Data mode detect = 1024 (8192 sec) (see note)

Table 61. LFCTL 3 Register Field Des criptions (continued)

Field Description

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12.17.4 LFR Control Register 4 (LFCTL4)

LFCTL4 contains local interrupt enable control bits. The provided I-interrupts are not globally masked by the I bit in the CPU’s

CCR, setting one or more of these interrupt enable control bits will cause a CPU interrupt to be requested whenever the flag bit

associated with the corresponding LFR interrupt source becomes set. It is good practice to clear any flag bits in the LFS register

before setting interrupt enable bits in this register in order to avoid an immediate interrupt request.

$0023 Bit 7 654321Bit 0

RLFDRIE LFERIE LFCDIE LFIDIE DECEN VALEN TIMOUT[1:0]

Reset: 00001100

Figure 79. LFR Control Register 4 (LF C TL4 )

Table 62. LFCTL4 Register Field Descriptions

Field Description

LFDRIE

LFR Data Register Full Interrupt Enable — This read/write bit enables interrupts to be requested when the LFR data register

is full. Reset clears LFDRIE.

0 LFDRF interrupts disabled. Use software polling.

1 LFR Data Register Full interrupts are enabled. If LFDRIE is set,

then an interrupt is requested when LFDRF = 1.

LFERIE

LFR Error Interrupt Enable — This read/write bit enables interrupts to be requested when the LFR detects an error in reception

of a non-Manchester encoded bit time following the SYN C time. Reset clears LFERIE.

0 LFERF interrupts disabled. Use software polling.

1 LFERF interrupts are enabled. If LFERIE is set, then an interrupt is requested when LFERF = 1.

LFCDIE

LFR Carrier Detect Interrupt Enable — This read/write bit enables the LFCDF interrupt when the LFR detects the number of

samples with an LF signal defined by the LFCDTM bits in the LFCTL3 register . The LFCDIE is ignored when the LFR is operating

in the data mode (CARMOD = 0), except when DECEN is cleared. Reset clears LFCDIE.

0 LFCDF interrupts disabled.

1 LFR LFCDF interrupts are enabled. If LFCDIE is set, then an interrupt is requested when LFCDF = 1.

LFIDIE

LFR ID Detect Interrupt Enable — This read/write bit enables interrupts to be requested when the LFR detects a match to the

ID code selected in the LFIDH:L registers. Reset clears LFIDIE.

0 LFIDF interrupts disabled.

1 LFIDF interrupts are enabled. If LFIDIE is set, then an interrupt is requested when LFIDF = 1.

DECEN

LF Digital Decode Enable — This read/write bit enables the data processing by the digital decoder. When

disabled, the frame format (Manchester , data-rate, SYNC, data) is not checked. There is no more error flag assertion (data, error,

ID). The MCU should then poll the LFDO bit to extract from the analog detector the bit stream. Reset sets the DECEN bit.

0 Digital decoder is disabled.

1 Digital decoder is enabled.

VALEN

LF Validation Enable — This read/write bit enables the carrier validation process. Reset sets this bit.

0 Carrier Validation disabled.

1 Carrier Validation enabled.

1:0

TIMOUT

[1:0]

SYNC Time Out Select — These two read/write bits select the period of time that the LFR will search for a SYNC pattern in the

data mode. If the SYNC pattern is not detected the LFR will be turned off af ter this delay time. These time intervals are clocked

by the internal LFRO clock. Reset clears TIMOUT bit.

00 SYNC word is continuously searched — no timeout.

01 SYNC search time set to nominal 8 milliseconds.

10 SYNC search time set to nominal 24 milliseconds.

11 SYNC search time set to nominal 48 milliseconds.

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12.17.5 LFR Status Register (LFS, LPAGE = 0)

LFS contains the data ready status flags. It is only accessible when the LPAGE bit is clear.

$0024 Bit 7 654321Bit 0

RLFDRF LFERF LFCDF LFIDF LFOVF LFEOMF LPSM 0

WLFIAK

Reset: 00000010

= Reserved

Figure 80. LFR Status Register (LFS, LPAGE =0)

Table 63. LFS Register Field Descriptions

Field Description

LFDRF

LF Data Ready Flag — This read-only status flag is set when a complete byte of data has been received by the LFR. An interrupt

is sent to the MCU if the LFDRIE bit is set. Clear LFDRF by writing a one to the LFIAK bit or reading the LFDA T A register . LFDRF

is also cleared by reset.

0 No new data in LFDATA register.

1 A new byte of data has been received and can be r ead from the LFDATA register.

LFERF

LF Receive Error Flag — In data receive mode, this read-only status flag is set when a non-standard bit time is detected in the

Manchester data mode. Any received data bits before the error occurs are placed in the data buffer. In carrier detect mode, this

read-only status flag is not used and remains clear. An interrupt is sent to the MCU if the LFERIE bit is set. Clear LFERF by

writing a one to the LFIAK bit. LFERF is also cleared by reset.

0 Normal operation.

1 Error detected in the Manchester data mode.

LFCDF

LF Carrier Pulse Detect Flag — In carrier detect mode, this read-only status flag is set when the number of consecutive carrier

validations set by the LFCC bits in is reached. Note that the LFCC function is not working if TOGMOD = 1. Clear LFCDF by writing

a one to the LFIAK bit. LFCDF is also cleared by reset.

0 Normal operation.

1 Carrier detection has occurred.

LFIDF

LF ID Detect Flag — In data receive mode, this read-only status flag is set when the received ID matches the stored value. This

interrupt can be generated even if no data bits follow the ID. An interrupt is sent to the MCU if the LFIDIE bit is set. Clear LFIDF

by writing a one to the LFIAK bit. LFIDF is also cleared by reset.

0 Normal operation.

1 wakeup ID has been detected.

LFOVF

LF Receive Data Overflow Flag — In data receive mode, this read-only status flag is set when a complete byte of data has

been received and written into the LFDATA register, but the previously received byte was not read from LFDATA register yet.

This indicates that the MCU has lost the previously received data byte. In carrier detect mode, this read-only status flag is not

used and remains cleared. No separate interrupt is generated by this specific flag bit because the LFDRF flag would serve that

purpose. Clear LFOVF by writing a one to the LFIAK bit. LFOVF is also cleared by reset.

0 Normal operation.

1 Previous data over-written before MCU read it.

LFEOMF

LF Receive Data EOM Flag — In data receive mode, this read-only status flag is set when a complete byte of data has b een

received and written into the LFDA T A register and an end-of-message Manchester encoding error occurs. In carrier detect mode,

this read-only status flag is not used and remains clear . No interrupt is generated by this flag bit because the LFERF flag would

serve that purpose. Clear LFEOMF by writing a one to the LFIAK bit. LFEOMF is also cleared by reset.

0 No EOM detected.

1 EOM detected.

LPSM

Low Power Sniff Mode — This bit used to activate the low power consumption during SNIFF mode. It saves approximately 1

A with a trade-off of an additional 200 s in transition from carrier to data mode. LPSM is set by reset.

0 Low time transition from carrier to data mode

1 Low consumption during sniff mode

LFIAK

LF Interrupt Acknowledge — Writing a one to the LFIAK bit clears the LFDRF, LFERF, LFCDF, LFIDF, LFOVF and LFEOMF

flag bits. When a one is written to the LFIAK, it is automatically cleared at the next positive edge of the MCU bus clock. Then,

reading the LFIAK bit is allowed but will always return zero. Writing a zero the LFIAK bit has no effect. Reset has no effect on

this bit.

0 No effect.

1 Clears the LFDRF, LFERF, LFCDF, LFIDF, LFOVF and LFEOMF flag bits.

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12.17.6 LFR Data Register (LFDATA, LPAGE = 0)

The LFDATA is a read-only register that contains the most recent received data value. It is only accessible when the LPAGE bit

is clear. As data is serially received by the LFR, it is assembled into 8-bit values. When a new complete 8-bit value is received,

it is moved into the LFDATA register , over-writing any previous value, and the LFDRF data ready flag is set to indicate a value is

available for the MCU to read. If a previous value was ready but was not read out of the LFDA TA register before a new data byte

is ready, the LFOVF overflow flag is also set to indicate this overflow condition. Writes to LFDATA have no meaning or effect.

12.17.7 LFR ID Registers (LFIDH:LFIDL, LPAGE = 0)

These two 8-bit read/write registers hold one of two ID values for LF messages. They are only accessible when the LPAGE bit

is clear. The type of ID checking can be selected or disabled by us ing the IDSEL[1:0] bits in the LFCTL1 register. When ID

checking is enabled, the ID value received through the LF R must match the contents of the LFIDH and/or LFIDL registers

depending on the IDSEL bits or the message will be ignored and the MCU will remain in standby mode to minimize power

consumption. All these bits are cleared by a reset.

$0025 Bit 7 654321Bit 0

RRXDATA[7:0]

Reset: 00000000

= Reserved

Figure 81. LFR Data Register (LFDATA) when LPAGE = 0

Table 64. LFDATA Register Field Descriptions

Field Description

7:0

RXDATA

[7:0]

Receive Data [7:0] — This is the received data from the L FR when in the data mode. All bits are read-only and any writes to

these bits will be ignored. Reading this register will clear the LFDRF.

$0026 Bit 7 6 5 4 3 2 1 Bit 0

RID[0:7]

Reset: 00000000

Figure 82. LFR ID Low Byte (LFIDL)

$0027 Bit 7 6 5 4 3 2 1 Bit 0

RID[15:8]

Reset: 00000000

Figure 83. LFR ID High Byte (LFIDH)

Table 65. LFR ID Register Field Description

Field Description

ID[15:0] ID bits 15 through 0 — These read/write bits contain bits 15 through 0 of the 16-bit ID value.

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12.17.7.1 LF Control E - LFCTRLE

12.17.8 LFR Control Register D (LFCTRLD, LPAGE =1)

The LFCTRLD register contains two control bits for the LF detector and decoder . It is only accessible when the LPAGE bit is set.

$0021 Bit 7 6 5 4 3 2 1 Bit 0

RAZSC2 AZSC1 AZSC0

Reset: 00000000

= Reserved

Figure 84. LF Control E (LFCTRLE)

Table 66. LFCTRL E Register Field Description

Field Description

7-3

Reserved Reserved bits — Not for user access.

2-0

AZSC

LOGAMP AZ Sequencer Control — Control bits for AZ and trim within the LOGAMP.

X00 Nominal AZ sequence - recommended setting

X01 Short amp output release, max delay with Rects

X10 Short amp output release, max delay with Amp input

X11 All short, max delay with end of AZ

0XX Nominal sensitivity trim - recommended setting

1XX Sensitivities shifted by - 4 trim steps

$0022 Bit 7 6 5 4 3 2 1 Bit 0

RAVFOF[1:0] DEQS AZDC[1:0] ONMODE CHK125[1:0]

Reset: 00000000

Figure 85. LFR Control Register D (LFCTRLD, LPAGE =1)

Table 67. LFCTRLD Register Field Descriptions

Field Description

7-6

AVFOF

[1:0]

SUM AZ release delay — Control the delay between falling edge of SUM d_az_en input and falling edge of internal AZ control

line.

00 No delay

01 No delay

10 One-half of 125 kHz clock period delay - recommended setting

11 One and one-half of 125 kHz clock periods delay

DEQS

DeQing status register — This read-only status bit allows the reading of the effective activation of the DeQing System.

0 DeQing system not activated

1 DeQing system activated

4-3

AZDC

[1:0]

AZ Digital Control of AZ triggering — In data receive mode, this bits control the triggering of AZ sequence with respect to both

LFCPTAZ value (ref. LFCTRLB register) and the state of the demodulation input data state.

00 AZ starts after LFCPTAZ numbers of input data edges.

01 Z starts randomly adding -1, 0 or 1 to LFCPTAZ value between each AZ.

10 AZ starts after LFCPTAZ numbers of input data edges and when the input data (d_data) state is 0.

11 AZ starts after LFCPTAZ numbers of input data edges and when the input data (d_data) state is 1 -

recommended setting.

ONMODE

ON Behavior Mode — This read/write bit selects how an error will affect the ON time. This bit is cleared by reset.

0 Any error will stop the ON time.

1 If remaining ON time, the LFR w ill go back to sniff mode at any error - recommended setting.

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NOTE

Setting CHK125[1:0] to either 0x01 or 0x10 increases the immunity to noise and therefore

carries the side effect of narrowing the 125 kHz carrier bandwidth tolerance.

12.17.9 LFR Control Register C (LFCTRLC, LPAGE =1)

The LFCTRLC register contains control bits for the LF detector and decoder. It is only accessible whe n the LPAGE bit is set.

1-0

CHK125

[1:0]

Accurate 125 kHz Check — The bit controls the CARVAL frequency check method.

00 CARVAL validates on n (2*32 s packets), n depending on LFCDTM value - recommended setting for Low

Sensitivity mode.

01 CARVAL validates on n (1*32 s packet + 4*8 s packets), n depending on LFCDTM value - optional recommended

setting for High Sensitivity mode.

10 CARVAL validates n (8*8 s packet), n depending on LFCDTM value - optional recommended

setting for High Sensitivity mode.

11 Same as 00.

$0023 Bit 7 6 5 4 3 2 1 Bit 0

RAMPGAIN[1:0] FINSEL[1:0] AZEN LOWQ[1:0] DEQEN

Reset: 1100100 1

Figure 86. LFR Control Register C (LFCTRLC, LPAGE =1)

Table 68. LFCTRL C Register Field Descriptions

Field Description

7-6

AMPGAIN

[1:0]

3rd Amplifier gain — These bits controls the 3rd amplifier gain.

00 Gain of 2 - recommended setting

01 Gain of 3

10 Gain of 4

11 Gain of 6

5-4

FINSEL

[1:0]

Final stage select — These bits select the final stage of the LOGAMP.

00 Continuous time biasing - Fixed Gain 6

01 Continuous time biasing - Programmable Gain - recommended setting

10 4th rectifier disabled

11 4th rectifier disabled

AZEN

Data AZ enable — This bit allows the AZ sequence during data frame.

0 AZ during data disabled

1 AZ during data enabled - recommended setting

2-1

LOWQ

[1:0]

DeQing Resistor — These bits select the resistor added in parallel to the input network.

00 4 k

01 2 k

10 1 k

11 500 

DEQEN

DeQing System enable — The bit controls the DeQing system.

0 DeQing disabled.

1 DeQing enabled.

Table 67. LFCTRLD Register Field Descriptions (continued)

Field Description

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12.17.10 LFR Control Register B (LFCTRLB, LPAGE = 1)

The LFCTRLB register contains control bits for the LF detector and decoder. It is only accessible when the LPAGE bit is set.

$0024 Bit 7 6 5 4 3 2 1 Bit 0

RHYST[1:0] LFFAF LFCAF LFPOL LCPTAZ[2:0]

Reset: 11000100

Figure 87. LFR Control Register B (LFCTRLB, LPAGE =1)

Table 69. LFCTRL B Register Field Descriptions

Field Description

7-6

HYST

[1:0]

Control slicer hysteresis

00 20 mV hysteresis

01 40 mV hysteresis

10 50 mV hysteresis

11 30 mV hysteresis - recommended setting

5-4

LFFAF;

LFCAF

Average filter bi-phase filtering control — Activates bi-phase filtering and control offset value

00 Standard low pass filtering activated - recommended setting

01 Standard low pass filtering activated

10 Bi-phase filtering activated - Low offset from input signal low level

11 Bi-phase filtering activated - High offset from input signal low level

LFPOL

LF Manchester Polarity Select — This read/write bit selects the polarity of the transition in the middle of the bit time. The LFPOL

is not used in Carrier mode. Reset clears LFPOL bit.

0 Zero is falling edge in middle of a bit time, one is a rising edge in the middle of bit time.

1 Zero is rising edge in middle of a bit time, one is a falling edge in the middle of bit time.

2-0

LFCPTAZ

[2:0]

LF auto-zero counter — Applications to set these bits to 0x06 for proper LF operation. These bits tune the minimum number of

data edges between two auto-zero requests during a data frame.

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12.17.11 LFR Control Register A (LFCTRLA, LPAGE = 1)

The LFCTRLA register contains control bits for the LF detector and factory test selects. It is only accessible when the LPAGE bit

is set.

$0025 Bit 7 6 5 4 3 2 1 Bit 0

RLFCC[3:0]

Reset: 00000000

= Reserved

Figure 88. LFR Control Register A (LFCTRLA, LPAGE =1)

Table 70. LFCTRL A Register Field Descriptions

Field Description

7-4

Reserved Reserved bits — Not for user access.

3-0

LFCC

[3:0]

LF Successive Carrier Validations Counter — The value of the LFCC[3:0] bits define how many times the car rier detect

sample ON time detected an LF carrier signal before the LFCDF flag bit set. The flag will be risen when the number of ON

samples with a detected carrier greater than the LFCDTM[3:0] reaches the value of the LFCC[3:0] bits plus one. The internal

count of detected carrier pulses will increment the count as long as they are consecutive samples. When a sample is encountered

without any detected carrier the count will be reset.

The LFCC register is considered reset in data mode. The first carrier validation will lead to start up of the receiver chain.

This feature allows the user to define a number of consecutive carrier detections are required before the flag is risen; and is useful

in detecting long duration carrier pulses.

This counter is disabled if TOGMOD = 1.

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13 RF Module

It is not intended that the RFM may be actively powered up and/or transmitting RF data while physical parameter measurements

are being made; or during the time that the LFR may be actively receiving/decoding LF signals. The resulting interactions will

degrade the performance of the RF output spectrum.

The FXTH870xD consists of an RF module (RFM) with external crystal-driven oscillator, VCO, fractal-n PLL and RF output

amplifier (PA) for an antenna. It also contains a small state machine controller , random time generator and hardware data buffer

for automated output or direct control from the MCU. The overall block diagram is shown in Figure 89.

Figure 89. RF Transmitte r Block Diagram

13.1 RF Data Modes

There are two modes of operation in using the RF output in either the data buffer mode or MCU direct mode.

13.1.1 RF Data Buffer Mode

In the RF data buffer mode the transmissions are sent by dedicated logic hardware while the MCU can be put into a low power

mode until the transmission is completed. This RF state machine is clocked by the MFO which is enabled when the SEND bit is

set and when any of the LFR, SMI or MCU are operating.

The RF data buffer consists of a dedicated RFM state machine and a 256-bit data buffer. Th e RF data buffer is loaded with

whatever data pattern the user software creates. The number of data bits to be sent is selected by the FRM[7:0] control bits. The

control logic is triggered by the SEND control bit when it is time to transmit the data which is sent to the RF stage after being

encoded as either Manchester, Bi-Phase or NRZ data according to the method selected by the CODE[1:0] bits as described in

Section 13.17.

Before the data can be transmitted the RFM control logic enables the external crystal oscillator and phase-locked-loop to initialize

before the RF output stage can begin transmission.

CRYSTAL

CONTROL

REGISTERS

AMP

VCO

PHASE

DETECTOR

LOW-PASS

FILTER

FRACTIONAL-N

DIVIDER

OSCILLATOR

AND LOGIC

256-BIT

DATA BUFFER

MODULATION

CONTROL

STATE

MACHINE

MCU

AVDD

AVSS

VREG

RINT LFSR

RANDOM

GEN

MFO

500 kHz

VOLT

REG

AVDD

LVD

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The external crystal connected to the X0 and XI pins provides the carrier frequency as well as the data rate clock needed for the

data rates associated with the OOK or FSK modulation. Therefore the tolerance on the data rate will depend on the

characteristics of the external crystal.

Once the data buffer is emptied the data transfer stops; the RF output stage is turned off; and the SEND control bit is cleared and

an interrupt of the MCU may be generated to wake it from the STOP1 mode. The user can test that the transmission has

completed by reading back the state of the SEND control bit or the RFIF status bit.

There is also the option to send the same data frame from 1 to 16 times with interlaced time intervals when the RF transmitter

PA output stage is off. If multiple frames of data are to be transmitted within a datagram the spacing before the first frame and

between subsequent frames can be controlled by the RFM state machine in several ways:

1. Use of a programmable timer (random, base time, time adder).

2. No time delays.

In addition, the RFM crystal oscillator, VCO and PLL can be turned off during any interframe timing by use of the IFPD bit.

When using the data buffer mode the user’s software should not change any bits in the RFM registers after the SEND has been

set and the transmission is still in progress. Changing RFM register contents during a transmission can lead to data faults or

errors.

13.1.2 MCU Direct Mode

When the CODE[1:0] bits are both set the encoding is controlled directly by the MCU where the data to the RF output depends

on the state of the DA TA bit and the selected modulation scheme. In this mode the user software must control the RF output stage

to power up (using the SEND control bit), WAIT for the RF output stage to stabilize (monitor the RCTS status bit) and clock the

DATA to the RF output stage. In this mode the data rate and its stability will depend on the internal HFO oscillator.

Any transfers of data from the MCU will use the DATA bit which will be reflected as modulated data on the RF pin once the RF

output stage is set up to transmit. The maximum data rate in this mode will depend on the complexity of the user software and

the MCU clock rate.

The POL bit in this case simply inverts the state of the DATA bit before it drives the RF output stage.

The accuracy of the data rate in the MCU direct mode is directly dependant on the HFO accuracy.

13.2 RF Output Buffer Data Frame

When using the RF data buffer mode each frame of data is sent as 2 to 256 bits per frame with a possible two trailing bits for an

end-of-message, EOM, as shown in Figure 90. The actual data being transmitted in a given data frame and any combinations of

data frames into a single datagram is dependent on the user software.

The number of frames sent in a given datagram can be from 1 to 16 based on the FNUM[3:0] bits in the RFCR3. The 256-bit

buffer is divided into two pages of 128 bits as selected by the RPAGE bit in the RFCR2.

The data buffer is unloaded to the RF output starting with the least significant bit (RFD0) in the least signi ficant byte (RFB0) up

through the most significant bit (RFD127) in the most significant byte (RFB15). This is often referred to as “little-endian” data

ordering.

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Figure 90. Data Frame Formats

13.2.1 Data Buffer Length

The number of bits sent in a given transmission frame is selected by the FRM[7:0] control bits encoded as a direct binary number

plus one. This gives a range of 2 through 256 bits. Data written to data buffer bits above the highest bit number will be ignored.

Transmission always begins with the data written in the RFB0 location. When the requested number of bits have been transmitted

an interrupt to the MCU can be generated if the RFIE bit is set.

13.2.2 End of Message (EOM)

If the EOM control bit is set, then at the end of the data frame there will be carrier for a period of two bit times at level high for the

OOK modulation modes or fDATA1 for the FSK modulation modes. Following the EOM period there will be no carrier for either the

OOK or FSK modes. If the EOM control bit is clear, no EOM period will be added to the transmission.

EOM

256

Maximum

258-Bit Format

80-Bit Format

53-Bit Format

2-Bit Format Data in each byte defined by user software

Optional EOM

RFB0 RFB1 RFB2 RFB3 RFB4 RFB5 RFBA RFBB RFBC RFBD RFBE RFBF

RFB0 RFB1 RFB2 RFB3 RFB4 RFB5 RFB6 RFB7 RFB8 RFB9

RFB0 RFB1 RFB2 RFB3 RFB4 RFB5

RFB6

EOM

Bits [2:0]

with all byte lengths

Minimum

RFB0

Bits [1:0]

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13.3 Transmission Randomization

When there are two or more different transmitters, the clock rates of each may drif t into synchronism with each other; and there

is the possibility of RF data collisions and the loss of data from both transmitters. In order to reduce possible RF data collisions

each transmission will contain from 1 to 16 frames of data. Each frame may be spaced at after the initially timed transmission

start time and between any two data frames as shown in Figure 91.

Figure 91. Datagram Overview

The generation of the initial and interframe time intervals can be done with a combination of a programmable counter , a pseudo-

random interval generator and a frame counter as shown in Figure 92. The initial time interval can be done by adjusting the start

time using the MCU or using this interval timing gene rator.

Figure 92. Initial and Interframe Timing

SPACE

Time Not To Scale

SPACE

Interframe Intervals

1 to 16 Data Frames

With Identical Data

Start of Time

Interval for

Datagram

DATA FRAME DATA FRAME DATA FRAME

Space Intervals have No Carrier Frequency Output, equivalent to Data = 0

tDATA

Initial Interval

and may have the RFM crystal oscillator, VCO and PLL turned off by the IFPD bit.

Time Not To Scale

Interframe Interval 1

Start of Time

Interval for

Datagram

tBASE

Initial Interval

40 x tRAND tBASE tRAND tFN tBASE tRAND tFN

Interframe Interval 2

tBASE, tRAND and tFN may be all zero in the initial interval.

tBASE, tRAND and tFN may be all zero in an interframe interval.

All interframe intervals may have different tBASE, tRAND and tFN times.

Note: If tBASE and tFN are both set to non-zero, and tRAND is set to 0, the system

will decrement both tBASE and tFN simult aneously rather than serially, such that the

effective Interframe Interval will be equal to the larger of tBASE or tFN settings.

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13.3.1 Initial Time Interval

When generating an initial time interval the MCU loads the RFM interval generator variables and then goes into the STOP1 mode.

When the initial time interval ends the data in the RFM data buffer is automatically sent and the MCU will wake at the end of the

transmission. The initial time interval is made up of two components:

Eqn. 10

where: tINIT = Total time interval before first frame is transmitted in ms

tBASE = Base time in ms; 5 ms not recommended

tRAND = Pseudo-random time in ms based on a Galois 7-bit LFSR

The components of this time are described in the following sections.

13.3.2 Interframe Time Intervals

When generating an interframe time interval the MCU loads the RFM interval generator variables and then goes to the STOP1

mode. When the interframe time interval ends the data in the RFM data buffer is automatically sent and the MCU will wake at the

end of the transmission. The interframe time interval is made up of three components:

Eqn. 11

where: tIFRM = Total time interval between each transmitted frame in ms

tBASE = Base time in ms; 5 ms not recommended

tFN = Time adder in ms for frame number

tRAND = Pseudo-random time in ms based on a Galois 7-bit LFSR

The components of this time are described in the following sections.

13.3.3 Base Time Interval

The base time interval, tBASE, is used in the initial time interval and in datagram transmissions with two or more frames. The

programmable frame space interval is based on a simple 8-bit, count-down timer as described by the RFBT[7:0] control bits in

the RFCR4 register. This time interval is forced to zero when the RFBT [7:0] are all clear.

The range of the base time must be set to 0 or between 5 and 255 ms using a clock generated from the MFO divided by 125.

13.3.4 Pseudo-Random Time Interval

The pseudo-random time interval, tRAND, is used both in the initial and the interframe time intervals if the LF SR[6;0] bits are set

to something other than all zeros. When the ISPC bit is set the pseudo-random initial time interval before the first data frame will

be 40 times the value of tRAND.

When the LFSR[6:0] bits are used the tRAND time will vary based on a pseudo-random generated binary number using a Galois

linear feedback shift register (LFSR) implemented using the primitive polynomial for a 7-stage register as shown in Figure 93.

This LFSR creates a sequence of 127 binary numbers including $01 through $3F which are each repeated only once in each

sequence of 127 clocks of the shift register . The LFSR is initialized to $40 during power up of the device. When a random interval

is to be determined the contents of the LFSR are sampled as the “random number” for calculating the required interval time.

Following the use of the random interval the LFSR is clocked once to advance it to the next pseudo-random number.

The range of the pseudo-random time is 1 to 127 ms using a clock generated from the MFO divided by 125. The current value

of the LFSR can be changed and/or read by the LFSR[6:0] bits in the RFCR5 register.

tINIT tBASE 40 tRAND

+=

tIFRM tBASE tRAND tFN

++=

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Figure 93. LFSR Implementation

A value of all zeros in the LFSR will remain unchanged with every clock input and cannot be used as a starting “seed.”

The resulting range of times for the initial and interframe pseudo-random time will be as given in Table 71 for both the design

center and the variation resulting from th e tolerance of the MFO clock.

13.3.5 Frame Number Time

The frame number time, tFN, is only used between frames and is based on a selectable time from 0 to 63 ms and the number of

the frame that was just transmitted as given in Table 72. If the frame number time is not use d, the value of the selected time

should be set to zero. The maximum number of frames is defined by the FNUM[3:0] control bits.

The range of the frame number time is a multiple of 0 to 63 ms using a clock generated from the MFO divided by 125. The value

of this time multiple can be changed by the RFFT[5:0] bits in the RFCR6 register.

Table 71. Rando mization Interval Times

Time

Interval Randomization

Number Ideal Time Interval (ms) Time Interval Including MFO Tolerance (ms)

Minimum Maximum

Initial 1 40 37.2 42.8

127 5080 4347.2 5434.6

Interframe 1 1 0.93 1.07

127 127 118.1 135.9

Table 72. Frame Number Interval Times

Value of

FNUM[3:0] Number of

Frames Frame Interval Where

Time Added Nominal Frame Number Time Interval Added (ms)

Minimum Maximum

0 1 None n/a n/a

121 - 21 63

2 3 2 - 3 2 126

3 4 3 - 4 3 189

4 5 4 - 5 4 252

5 6 5 - 6 5 315

6 7 6 - 7 6 378

7 8 7 - 8 7 441

8 9 8 - 9 8 504

S0S1S2S3S4S5S6

CLK

RFMRST

7-BIT Random Number

Galois Primitive Polynomial = X7 + X3 + 1

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13.4 RFM in STOP1 Mode

The entire RF transmitter digital section can remain powered up, if enabled by the RFEN bit (see Section 5.3), when the MCU

goes into the STOP1 mode.

13.5 Data Encoding

The CODE[1:0] control bits select either Manchester, Bi-Phase, NRZ or MCU direct data encoding of each data bit being

transferred from the RF data buffer to the RF output stage. Further , the polarity of the selected encoding method can be inverted

using the POL control bit.

13.5.1 Manchester Encoding

When the CODE[1:0] bits are both clear the data is Manchester encoded format, with data transmitted as a transition in voltage

occurring in the middle of the bit time. The polarity of this transition is selected by the POL bit. When the POL bit is cleared, then

a logical LOW is defined as an increase in signal in the middle of a bit time and a logical HIGH is defined as a decrease in signal

in the middle of a bit time as shown in Figure 94. When the POL bit is set, then a logical LOW is defined as an decrease in signal

in the middle of a bit time and a logical HIGH is defined as a increase in signal in the middle of a bit time as shown in Figure 95.

Since there is always a transition in the middle of the bit time there must also be a transition at the start of a bit time if consecutive

“1” or “0” data are present.

13.5.2 Bi-Phase Encoding

When the CODE[1:0] bits are 0:1 then the data is Bi-Phase encoded format, with data transmitted as the presence or absence

of a transition in signal in the middle of the bit time. The polarity of this transition is selected by the POL bit. Unlike Manchester

coding there is always a signal transition at the boundaries of each bit time. When the POL bit is cleared, then a logical HIGH is

defined as no change in signal in the middle of a bit time and a logical LOW is defined as a change in the signal in the middle of

a bit time as shown in Figure 96. When th e POL bit is set, then a logical HIGH is defined as a change in signal in the middle of

a bit time and a logical LOW is defined as no change in the signal in the middle of a bit time as shown in Figure 97. Since there

is always a transition at the ends of the bit time consecutive bits of the same state may have two signal states (high or low) during

the middle of the bit time.

13.5.3 NRZ Encoding

When the CODE[1:0] bits are 1:0 then the data is NRZ encoded format, with data transmitted as either a high or low for the

complete bit time. The polarity of this state is selected by the POL bit. The Manchester and Bi-Phase encod ing can actually be

created using NRZ encoding running at twice the desired data rate.

9 10 9 - 10 9 567

10 11 10 - 11 10 630

11 12 11 - 12 11 693

12 13 12 - 13 12 756

13 14 13 - 14 13 819

14 15 14 - 15 14 882

15 16 15 - 16 15 945

Table 72. Frame Number Interval Times (continued)

Value of

FNUM[3:0] Number of

Frames Frame Interval Where

Time Added Nominal Frame Number Time Interval Added (ms)

Minimum Maximum

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Figure 94. Manchester Data Bit Encoding (POL = 0)

Figure 95. Manchester Data Bit Encoding (POL = 1)

LOW

BIT HIGH

BIT

FSK = fRF+ f

FSK = fRF - f

Bit Time

Consecutive “0”

Data Bits

Consecutive “1”

Data Bits

“001101”

Da ta Bits

OOK = fRF

OOK = OFF

Bit Time

LOW

BIT HIGH

BIT

FSK = fRF+ f

FSK = fRF - f

Bit Time

Consecutive “0”

Data Bits

Consecutive “1”

Data Bits

“001101”

Da ta Bits

OOK = fRF

OOK = OFF

Bit Time

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Figure 96. Bi-Phase Data Bit Encoding (POL = 0)

Figure 97. Bi-Phase Data Bit Encoding (POL = 1)

13.6 RF Output Stage

The RF output stage consists of a PLL, control logic and an output RF amplifier. Data is sent to the RF output stage from either

the RF data buffer or the DATA bit in the RFCR3 depending on the selected mode of operation as described in Section 13.1.

The RF output stage is enabled by the state of the SEND control bit. The PLL in the RF output stage will signal back via the RCTS

status bit when the PLL is locked and ready to transmit.

13.6.1 Modulation Method

The modulation control bit, MOD, described in Section 13.18, sets the modulation of the RF signal will be either amplitude shift

keying (OOK) or frequency shift keying (FSK) with several options for the frequency shift.

When operating in the FSK mode the internal, fractional-n PLL divider will be used to create the two carrier frequencies for data

zero and data one. This method is more effective and robust than “pulling” the external crystal in order to shift the carrier

frequency.

LOW

BIT HIGH

BIT

Bit Time

Consecutive “0”

Data Bits

Consecutive “1”

Data Bits

LOW

BIT

“001101”

Da ta Bits

HIGH

BIT

FSK = fRF+ f

FSK = fRF - fOOK = fRF

OOK = OFF

Bit Time Bit Time Bit Time

OOK = fRF

LOW

BIT HIGH

BIT

Bit Time

Consecutive “0”

Data Bits

Consecutive “1”

Data Bits

LOW

BIT

“001101”

Da ta Bits

HIGH

BIT

FSK = fRF+ f

FSK = fRF - fOOK = OFF

Bit Time Bit Time Bit Time

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13.6.2 Carrier Frequency

The carrier frequen cy is established mainly by the external crystal used, but a centering of the fractional-n PLL provides more

precise control. If the CF control bit is clear the PLL will be configured for a carrier center frequency of the 315 MHz. If the CF

control bit is set the PLL will be configured for a carrier center frequency of the 434 MHz.

13.6.3 RF Power Output

The maximum power output from the RF pin can be adjusted to one of 21 levels using the PWR[4:0] bits.

13.6.4 Transmission Error

Any transmission will be aborted if one of the following occurs:

1. The RCTS signal does not become active within the t LOCK time.

2. The PLL falls out of lock after once being set and the SEND bit is still active.

3. The XCO monitor output falls.

If either of these cases occurs the RF output will be turned off; the SEND control bit will be cleared; and the transmission error

status flag, RFEF, will be set. The RFEF bit triggers an interrupt of the MCU if the RFIEN is set. The RFEF bit is cleared by writing

a logical one to the RFIAK bit.

13.6.5 Supply Voltage Check During RF Transmission

A separate low voltage detector can be enabled during the RF transmission and a status bit checked for low voltage drops due

to a weak battery during the higher transmission currents. This RF LVD can be enabled by setting the RFLVDEN bit and the

resulting status is reported on the RFVF bit. The RFVF bit can be cleared by writing a logical one to the RFIAK bit if the supply

voltage has risen above the detect threshold. Further , if the voltage falls far enough for the VCO and PLL to fall out-of-lock, then

the RF output will be turned off and the transmission will be terminated.

13.6.6 RF Reset (RFMRST)

The RF state machine, crystal oscillator, PLL and VCO can be reset to the initial off state by the RFMRST signal generated by

one of the following methods:

1. Internal RFM power-on reset (RFPOR).

2. Writing a one to the RFMRST bit in the RFCR7.

Any of these reset methods will not alter any data stored in the data buffer.

13.7 RF Interrupt

The RFM will interrupt the MCU when the SEND bit is cleared at the end of a data buffer transmission. This interrupt occurs at

the end of a programmed set of frames. If the number of frame count FNUM[3:0] is set to zero, then only one frame is sent and

the interrupt occurs at the end of that first frame transmitted. If the number of the frame cou n t is greater than zero, then the

interrupt will be generated depending on the state of the IFID bit.

The interrupt will also create a flag bit, RFIF, which can be cleared by writing a logical one to the RFIAK bit. The interrupt can be

enabled/disabled by the RFIEN bit.

13.8 Datagram Transmission Times

In order to comply with FCC requirements in the US market the periodically transmitted datagram must be less than 1 second in

length and be separated by an off time that is at least 10 seconds or at least 30 times longer than the transmission time, whichever

is longer. The user software must adhere to this ruling for products intended for the US market.

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13.9 RFM Registers

The RFM contains twelve registers to control its functions and 32 registers to provide access to the output data buffer.

13.9.1 RFM Control Register 0 - RFCR0

The RFCR0 register contains eight control bits for setting the output data rate of the RFM as described in Figure 98.

The BPS[7:0] bits are set to $34 by an RFMRST signal which results in a default data rate of approximately 9600 bps.

13.10 RFM Control Register 1 - RFCR1

The RFCR1 register contains eight control bits for the RFM as described in Figure 99.

$0030 Bit 7 654321Bit 0

RBPS[7:0]

RFMRST: 00110100

Figure 98. RFM Control Register 0 (RFCR0)

Table 73. RFCR0 Field Descriptions

Field Description

7–0

BPS[7:0]

Data Rate - The BPS[7:0] control bits select the data rate for the transmitted datagrams as described by the following equation:

where:fDATA= Data rate in bits/second

fXTAL= External crystal frequency in Hz = 26 MHz

BPS= Value of data rate code (BPS[7:0])

Examples of the value for common data rates are given in Table 74. The BPS[7:0] control bits are set to $34 by the RFMRST

signal which results in a default data rate of 9600 bits/sec.

Table 74. Data Rate Option Examples

Data Rate BPS[7:0]

Decimal Value Data Rate BPS[7:0]

Decimal Value

Target Nominal fXTAL = 26 MHz Target Nominal fXTAL = 26 MHz

2000 bps 2000.0 249 4800 bps 4807.7 103

2400 bps 2403.8 207 5000 bps 5000.0 99

4000 bps 4000.0 124 9600 bps 9615.4 51

4500 bps 4504.5 110 19200 bps 19230.8 25

$0031 Bit 7 6 5 4 3 2 1 Bit 0

RFRM[7:0]

RFMRST: 00000000

Figure 99. RFM Control Register 1 (RFCR1)

fDATA

fXTAL

52 BPS 1+

------------------------------------- 5x105

BPS 1+

-------------------------

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13.11 RFM Control Register 2 - RFCR2

The RFCR2 register contains eight control bits for the RFM as described in Figure 100.

Table 75. RFCR1 Field Descriptions

Field Description

7-0

FRM[7:0]

Frame Bit Length - The FRM[7:0] control bits select the number of bits in each datagram. The number of bits is determined by

the binary value of the FRM[7:0] bits plus one. This makes the range of bits from 2 to 256. A value of $00 for the FRM[7:0] control

bits will result in no frames being sent. The FRM[7:0] control bits are cleared by RFMRST signal.

$0032 Bit 7 654321Bit 0

RSEND RPAGE EOM PWR[4:0]

RFMRST: 00000000

Figure 100. RFM Control Regi ster 2 (RFCR2)

Table 76. RFCR2 Field Descriptions

Field Description

SEND

Transmission Start Control- The SEND control bit starts the transmission of data held in the RFM data buf fer according to the

bit length specified by the FRM[7:0] bits. The SEND control bit is automatically cleared when the data buffer transmission has

ended or by the RFMRST signal. A transmission can be prematurely interrupted by writing a logical zero to the SEND bit.

0 Data transmission ended or transmission not in progress.

1 Start data transmission or transmission in progress.

RPAGE

Buffer Page Select — The RP AGE bit will select the lower or upper 16 bytes of the RFM data buffer when writing/reading to the

RFD0-RD15 registers. This bit also selects between the lower and upper banks of RFM registers at addresses $0038 through

$003B. This bit is cleared by a reset of the MCU.

0 Select the lower 16 bytes of the RFM data buffer.

1 Select the upper 16 bytes of the RFM data buffer.

EOM

End Of Message - The EOM control bit selects whether there will be two data bit times of data 1 carrier state at the end of each

datagram. The EOM control bit is cleared by a RFMRST.

0 EOM bit times not added.

1 EOM bit times added.

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4:0

PWR[4:0]

RF Amplifier Power Level - The PWR[4:0] control bits select the optimum power output of the RF power amplifier . These power

output levels assume optimal matching network to the RF pin. The PWR[4:0] control bits are cleared a RFM reset. The PWR

control bits are initially set to 0x00. This setting targets -10 dBm typical power output. The PWR control bits scale the typical

output power level from -1.5 to 8 dBm in steps of 0.5 dB and fixes the low power level mode to -10 dBm, The power control range

is defined as follows:

00000 set output power level to -10 dBm (Default Value)

00001 set output power level to -1.5 dBm

00010 set output power level to -1.0 dBm

00011 set output power level to -0.5 dBm

00100 set output power level to 0.0 dBm

00101 set output power level to 0.5 dBm

00110 set output power level to 1.0 dBm

00111 set output power level to 1.5 dBm

01000 set output power level to 2.0 dBm

01001 set output power level to 2.5 dBm

01010 set output power level to 3.0 dBm

01011 set output power level to 3.5 dBm

01100 set output power level to 4.0 dBm

01101 set output power level to 4.5 dBm

01110 set output power level to 5.0 dBm

01111 set output power level to 5.5 dBm

10000 set output power level to 6.0 dBm

10001 set output power level to 6.5 dBm

10010 set output power level to 7.0 dBm

10011 set output power level to 7.5 dBm

10100 set output power level to 8.0 dBm

Codes greater than 10100 are reserved for test purposes and should not be used.

Table 76. RFCR2 Fi eld Descriptions (continued)

Field Description

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13.11.1 Power Working Domains

The working areas of the RF transmitter are divided into several domains as defined in Figure 101.

PTYP

TA = 25 °C to 60 °C and VDD = 2.5 V to 3.6 V

PTYP is where the power step is adjusted to guarantee 5 dBm. The power consumption in this domain is specified at 5 dBm output

power step at nominal conditions of TA = 25 °C and VDD = 3 VDC.

PMIN

PMIN is where the power step is adjusted to guarantee a minimum of 3 dBm as shown in Figure 101. The power consumption in

this domain is given as the maximum consumption at whatever temperature of supply voltage condition. The PMIN domain is

subdivided into two areas according to the lowest supply voltage encountered (1.8 or 2.5 VDC).

PMIN_COLD TA = -40 °C to 0 °C and VDD = 1.8V to 3.6V

PMIN_HOT TA = 0 °C to 25 °C and VDD = 2.5 V to 3.6 V

TA = 60 °C to 125 °C and VDD = 2.5 V to 3.6 V

Figure 101. RF Power Domains

PMIN_COLD PMIN_HOT PMIN_HOT

PTYP

VDD = 2.5 V

VDD = 3.6 V

VDD = 3.0 V

VDD = 1.8 V

TA = -40 °C TA = 0 °C TA = 25 °C TA = 60 °C TA = 125°C

Typical Consu mption

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13.12 RFM Control Register 3 - RFCR3

The RFCR3 register contains five control bits for the RFM as described in Figure 102 which sets the number of frames in each

RF datagram.

$0033 Bit 7 654321Bit 0

RDATA IFPD ISPC IFID FNUM[3:0

RFMRST 00000000

Figure 102. RFM Control Regi ster 3 (RFCR3)

Table 77. RFCR3 Field Descriptions

Field Description

DATA

Data S tate - The DA TA bit determines the output state of the RF power amplifier when the RFM is in the MCU direct control mode

(CODE[1:0]=11)

0 RF output state low.

1 RF output state high.

IFPD

Interframe Power Down — The IFPD control bit selects whether the XCO and associated analog blocks are powered down

during interframe timing caused by the RFM. The IFPD control bit is cleared by the RFMRST signal.

0 The XCO remains powered up as long as the SEND bit is set.

1 The XCO is powered down during RFM controlled interframe timing events.

The restart of these functions will start 1 ms before the end of the timing interval if another

frame is to be transmitted.

ISPC

Initial Random Space— When the ISPC bit is set the initial time delay before the first frame will be enabled. This bit is cleared

by an RFM reset.

0 No initial time interval.

1 Initial time interval enabled.

IFID

Interframe Interrupt Delay — The IFID control bit selects whether the RFIF bit is set and the MCU is interrupted at the end of

each frame sent or at the end of the last frame in a multiple frame message. The IFID control bit is cleared by the RFMRST signal.

0 The RFIF bit is set and the MCU interrupted if the RFIEN bit is set, after the last frame transmitted.

1 The RFIF bit is set and the MCU interrupted if the RFIEN bit is set, only after the last frame

plus an additional interframe message is transmitted.

3-0

FNUM

[3:0]

FNUM[3:0] — The FNUM[3:0] bits set the number of frames transmitted in each RF datagram. The frames will be randomly

spaced apart as described it Section 13.3.These bits are cleared by an RFM reset. The number of frame transmitted is the binary

number plus one.

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13.13 RFM Control Register 4 - RFCR4

The RFCR4 register contains eight control bits to set the initial and interframe timing base timing variable as described in

Figure 103. A RFMRST signal clears the RFBT[7:0] bits.

13.14 RFM Control Register 5 - RFCR5

The RFCR5 register contains eight control bits to set the initial and interframe random timing variable as described in Figure 104.

A RFMRST signal clears the LFSR[6:0] bits causing the random time variable to be ignored.

$0034 Bit 7 654321Bit 0

RRFBT[7:0]

RFMRST: 10000000

Figure 103. RFCR4 Register - Base Time Variable

Table 78. RFCR4 Field Descriptions

Field Description

7:0

RFBT

[7:0]

Base Timer - The RFBT[7:0] control bits select the interframe timing between multiple frames of transmission. The base time

value is equal to a nominal one millisecond for each count of the RFBT[7:0] bits. The RFBT[7:0] control bits are cleared by the

RFMRST signal and must be set to either 0 or between 5 and 255.

$0035 Bit 7 654321Bit 0

RBOOST LFSR[6:0]

RFMRST: 00000000

Figure 104. RFCR5 Register - Pseudo-Random Time Var iab le

Table 79. RFCR5 Field Descriptions

Field Description

BOOST

BOOST - This bit controls the VCO power consumption in order to decrease the phase noise required by the Japanese

regulation. The BOOST control bit is cleared by the RFMRST signal.

0 The VCO runs at its lower power consumption level (higher phase noise).

1 The VCO runs at its higher power consumption level (lower phase noise).

6:0

LFSR[6:0]

Pseudo-Random Timer- The LFSR[6:0] bits select the current seed value of the LFSR when enabling pseudo-random timing

intervals when any of the LFSR[6:0] bits are set. The value written to this register is loaded into the actual LFSR when the SEND

bit is set. The time value is equal to a nominal one millisecond for each count of the resulting LFSR[6:0] bits.

A value of $00 placed in the LFSR causes the LFSR to stay at the $00 state on each clocking of the LFSR. To cause the LFSR

to cycle through its pseudo-random number sequence requires that any value other than $00 be written to the LFSR[6:0] bits.

Note: If RFBT[7:0] and RFFT[5:0] are both set to non-zero, and LFSR[6:0] is set to 0x00, the system will decrement both RFBT

and RFFT simultaneously rather than serially, such that the effective Interframe Interval will be equal to the larger of RFBT or

RFFT settings.

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13.15 RFM Control Register 6 - RFCR6

The RFCR6 register contains eight control bits to set the initial and interframe frame number timing variable as described in

Figure 105. A RFMRST signal clears the RFFT[5:0] bits.

13.16 RFM Control Register 7 - RFCR7

The RFCR7 register contains four control bits and four status bits for the RFM as described in Figure 106.

$0036 Bit 7 654321Bit 0

RVCO_GAIN[1:0] RFFT[5:0}

RFMRST: 10000000

Figure 105. RFCR6 Register - Frame Number Time - RFTS[1:0] = 1:0

Table 80. RFCR6 Field Descriptions

Field Description

7:6

VCO_GAIN

[1:0]

VCO Gain Selection - These bits control the VCO gain. The VCO_GAIN[1] bit is set and the VCO_GAIN[0] bit is cleared by the

RFMRST signal. Not normally need to be adjusted by the end user.

5:0

RFFT[5:0]

Frame Number Timer - The RFFT[5:0] control bits select the interframe timing between multiple frames of transmission. The

time value is equal to a nominal one millisecond for each count of the RFFT[5:0] bits multiplied by the frame number of the last

transmitted frame. The RFFT[5:0] control bits are cleared by the RFMRST signal.

$0037 Bit 7 6 5 4 3 2 1 Bit 0

RRFIF RFEF RFVF 0RFIEN RFLVDEN RCTS 0

WRFIAK RFMRST

RFMRST: 00000000

= Reserved

Figure 106. RFM Transmit Control Regis t ers (RFCR7)

Table 81. RFCR7 Field Descriptions

Field Description

RFIF

RF Interrupt Flag— The read-only RFIF status bit indicates if the RF transmission has ended properly when using the data buffer

mode and the SEND bit has been cleared. Writes to this bit will be ignored. The RFIF status bit is cleared by writing a logical one

to the RFIAK bit or the RFMRST bit. RFMRST signal clears this bit.

0 RF transmission in progress or not in the data buffer mode.

1 RF transmission completed in the data buffer mode.

RFEF

RF Transmission Error Flag— The read-only RFEF status bit indicates if there was an error in the current or prior RF

transmission as described in Section 13.6.4. Writes to this bit will be ignored. The RFEF status bit is cleared by writing a logical

one to the RFIAK bit or the RFMRST bit. RFMRST signal clears this bit.

0 No RF transmission error occurred.

1 RF transmission error occurred.

RFVF

RF LVD Tr igger Flag— When the RF LVD is enabled and the supply voltage falls below the threshold, the read-only RFVF flag

will be set if the RFLVDEN bit is set. Writes to this bit will be ignored. The RFVF status bit is cleared by writing a logical one to

the RFIAK bit or the RFMRST bit. RFMRST signal clears this bit

0 Voltage is and has been above RF LVD rising threshold or the RF LVD is disabled.

1 Voltage has dropped below the RF LVD falling threshold since last reset of this bit.

RFIAK

Acknowledge RF Interrupt Flags— Writing a one to the RFIAK bit clears the RFIF, RFEF and RFVF flag bits. Writing a zero to

the RFIAK bit has no effect on the RFIF, RFEF and RFVF flag bits. The RFMRST signal has no effect on this bit.

0 No effect.

1 Clear the RFIF, RFEF, and RFVF bits.

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13.17 PLL Control Registers A- PLLCR[1:0], RPAGE = 0

The PLLCR[1:0] registers contain 16 control bits for the RFM as described in Figure 107. These bits are only accessible when

the RPAGE bit is cleared.

RFIEN

RF Interrupt Enable— The RFIEN bit enables the RFIF, the RFEF and the RFVF bits to generate an interrupt to the MCU. The

RFMRST signal clears this bit.

0 RF interrupts disabled.

1 RF inter rupts enabled.

RFLVDEN

RF LVD Enable — When the RFLVDEN bit is set, the RF LVD circuit will be enabled, and the RF LVD events are routed to the

RF LVD Trigger Flag. This bit is cleared by the RFMRST signal.

0 RF LVD disabled.

1 RF LVD enabled.

RCTS

RF Clear T o Send St atus— When the RCTS bit is set the RF XCO, VCO and PLL have started and locked and the RFM is ready

to send data. This bit is cleared by the RFMRST signal.

0 RFM not ready to send.

1 RFM ready to send.

RFMRST

RFM Reset — Writing a one to the RFMRST bit will completely reset the RFM and its registers. This bit is not affected by a reset

of the MCU. This bit will always read as a zero.

0 No effect.

1 Reset RFM.

$0038 Bit 7 654321Bit 0

RAFREQ[12:5]

RFMRST: 00000000

$0039

RAFREQ[4:0] POL CODE

RFMRST: 00000000

Figure 107. PLL Con t rol Registers A (PLLCR[1:0], RPAGE = 0)

Table 82. PLL CR[1:0] Field Description s

Field Description

PLLCR0

7:0

AFREQ

12:5

PLLCR1

7:3

AFREQ

4:0

PLL Divider Rati o A- The AFREQ[12:0] control bits select the PLL divider ratio for a data zero in the FSK mode of modulation

as described by the following equation:

where:

fDATA0 = RF Carrier frequency for a data zero in MHz

fXTAL = External crystal frequency in MHz, 26 MHz

CF = State of the CF carrier select bit

AFREQ = Decimal value of the AFREQ[12:0] binary weighted bits

The AFREQ[12:0] control bits are cleared by the RFMRST signal. 1 LSB of AFREQ[12:0] = 3.17 kHz.

POL

Data Polarity - The POL control bit selects the polarity of the data encoding selected by the CODE[1:0] bits. The POL control bit

is cleared by the RFMRST signal.

0 NRZ and MCU direct DATA bit data non-inverted and Manchester encoding polarity

as in Figure 95 and Bi-Phase encoding polarity as in Figure 97.

1 NRZ and MCU direct DATA bit data inverted and Manchester encoding polarity

as in Figure 94 and Bi-Phase encoding polarity as in Figure 96.

Table 81. RFCR7 Fi eld Descriptions (continued)

Field Description

fDATA0 fXTAL 12 4 CF+

AFREQ

8192

---------------------





=

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13.18 PLL Control Registers B- PLLCR[3:2], RPAGE = 0

The PLLCR[3:2] registers contain 16 control bits for the RFM as described in Figure 108. These bits are only accessible when

the RPAGE bit is cleared.

1:0

CODE

[1:0]

Data Encoding and Source- The CODE[1:0] control bits select the type of data encoding and source of data for the RF output.

The CODE[1:0] control bits are cleared by the RFMRST signal.

00 Manchester encoded data from the RFM data buffer.

01 Bi-Phase encoded data from the RFM data buffer.

10 NRZ direct data from the RFM data buffer (can be mixed NRZ and Manchester at 2X the data rate).

11 MCU direct mode with RF output driven by the state of the DATA bit.

$003A Bit 7 654321Bit 0

RBFREQ[12:5]

RFMRST: 00000000

$003B

RBFREQ[4:0] CF MOD CKREF

RFMRST: 00000000

Figure 108. PLL Con t rol Registers B (PLLCR[3:2], RPAGE = 0)

Table 83. PLL CR[3:2] Field Description s

Field Description

PLLCR2

7:0

BFREQ

12:5

PLLCR3

7:3

BFREQ

4:0

PLL Divider Ra tio B- The BFREQ[12:0] control bits select the PLL divider ratio for a data one in either the OOK or FSK modes

of modulation as described by the following equation:

where:fCARRIER = RF Carrier frequency in MHz

fXTAL = External crystal frequency in MHz

CF = State of the CF carrier select bit

BFREQ = Decimal value of the BFREQ[12:0] binary weighted bits

The BFREQ[12:0] control bits are cleared by the RFMRST signal. 1 LSB of BFREQ[12:0] = 3.17 kHz.

Carrier Frequency - The CF control bit selects the optimal VCO setup and correct divider for the 500 kHz reference clock to the

MCU on DX based on the external crystals required for the desired carrier frequency. The CF control bit is cleared by the

RFMRST signal.

0 Configured for 315 MHz, 12.1154 PLL divider using a 26.000 MHz external crystal.

1 Configured for 434 MHz, 16.6923 PLL divider using a 26.000 MHz external crystal.

MOD

RF Modulation Method - The MOD control bit selects the method of modulating the RF. The MOD control bit is cleared by the

RFMRST signal.

0 Configured for OOK.

1 Configured for FSK.

CKREF

Generated Clock Reference - Generates the DX signal to the TPM1 module for determining the other

clock frequencies:

X signal not generated.

X 500 kHz signal connected to the TPM1 module.

Table 82. PLLCR[1:0] Field Description s (continued)

Field Description

fDATA1 fXTAL 12 4 CF+

BFREQ

8192

--------------------





=

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13.19 EPR Register - EPR (RPAGE = 1)

The EPR register contains eight control bits for the RFM as described in Figure 109. The function of the upper 4 bits depends on

the state of the VCD_EN bit.

$0038 Bit 7 654321Bit 0

RPLL_LPF_[2:0] PA_SLOPE VCD_EN

RFMRST: 00110010

= Reserved

Figure 109. RFM EPR Registers (EPR, RPAGE = 1, VCD_EN = 0)

$0038 Bit 7 654321Bit 0

RVCD[3:0] PA_SLOPE VCD_EN

RFMRST: ———— 0010

= Reserved

Figure 110. RFM EPR Registers (EPR, RPAGE = 1, VCD_EN = 1)

Table 84. EPR Field Descriptions

Field Description

Reserved Reserved bit — Not for user access if the VCD_EN bit is clear.

6-4

PLL_LPF_[2:0] Low Pass Filter Selection - These read/write bits select the PLL low pass filter. A reset sets these bits to $03. These bit s

are only accessible if the VCD_EN bit is clear.

7-4

VCD[3:0]

VCO Calibration Count Difference - These read-only bits show the count difference from “ideal” when the VCO calibration

machine is finished (see Section 13.21). These bits are only accessible when the VCD_EN bit is set. Writing to these bits

when the VCD_EN bit is set has no effect. The reset state is undefined.

3-2

Reserved Reserved bits — Not for user access.

PA_SLOPE PA Output Slope Selection — This read/write bit controls the output slope of the RFM PA output. This bit is set by the

RFMRST signal.

VCD_EN

VCD Enable bit — This bit allows access to the VCD[3:0] bits. This bit is cleared by the RFMRST signal.

0 PLL_LPF_[2:0] bits accessed.

1 VCD[3:0] bits accessed.

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13.20 RF DATA Registers - RFD[31:0]

The RFD registers contain 256 read/write bits for the RFM to use when outputting data as described in Section 13.2. The 256-

bit buffer is divided into two pages of 128 bits as selected by the RPAGE bit in the RFCR2. These as describ ed in Figure 111.

These bits are unaffected by any reset.

The data buffer is unloaded to the RF output starting with the least significant bit (RFD0) in the least signi ficant byte (RFB0) up

through the most significant bit (RFD255) in the most significant byte (RFB31). This is often referred to as “little-endian” data

ordering. The output of this data by the RFM in all 256 bits locations is not dependent on the state of the RPAGE bit.

Bit 7654321Bit 0

$003C RFD[7:0] for RPAGE=0, RFD[135:128] for RPAGE=1

$003D RFD[15:8] for RPAGE=0, RFD[143:136] for RPAGE=1

$003E RFD[23:16] for RPAGE=0, RFD[151:144] for RPAGE=1

$003F RFD[31:24] for RPAGE=0, RFD[159:152] for RPAGE=1

$0040 RFD[39:32] for RPAGE=0, RFD[167:160] for RPAGE=1

$0041 RFD[47:40] for RPAGE=0, RFD[175:168] for RPAGE=1

$0042 RFD[55:48] for RPAGE=0, RFD[183:176] for RPAGE=1

$0043 RFD[63:56] for RPAGE=0, RFD[191:184] for RPAGE=1

$0044 RFD[71:64] for RPAGE=0, RFD[199:192] for RPAGE=1

$0045 RFD[79:72] for RPAGE=0, RFD[207:200] for RPAGE=1

$0046 RFD[87:80] for RPAGE=0, RFD[215:208] for RPAGE=1

$0047 RFD[95:88] for RPAGE=0, RFD[223:216] for RPAGE=1

$0048 RFD[103:96] for RPAGE=0, RFD[231:224] for RPAGE=1

$0049 RFD[111:104] for RPAGE=0, RFD[239:232] for RPAGE=1

$004A RFD[119:112] for RPAGE=0, RFD[247:240] for RPAGE=1

$004B RFD[127:120] for RPAGE=0, RFD[255:248] for RPAGE=1

Figure 111. RF Data Registers (RFD[31:0])

Table 85. RFD[31:0] Fi eld Descriptions

Field Description

RFD

15:0

RPAGE=0

RFD

[127:0]

RF Data Registers Lower 128 bits - These are read/write bits that hold the lower 128 bits of possible data to be sent by the

RFM. Access to the lower 128 bits occurs when the RPAGE bit is clear. These bits are unaffected by any reset.

RFD

31:16

RPAGE=1

RFD

[255:128]

RF Data Registers Upper 128 bits - These are read/write bits that hold the upper 128 bits of possible data to be sent by the

RFM. Access to the lower 128 bits occurs when the RPAGE bit is clear. These bits are unaffected by any reset.

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13.21 VCO Calibration Machine

The RFM incorporates a VCO calibration machine which works in conjunction with the VCO. The calibration machine selects the

optimal VCO sub-band with respect to a predefined reference voltage applied to the VCO.

• Calibration supports maxband VCO sub-bands. maxband corresponds to the band where the VCO frequency is maximum.

• A successive approximati on algorithm is used to calculate the optimum sub-band.

•F

c, the Center Frequency (AFREQ+BFREQ)/2 is used as the reference frequency for the VCO calibration in FSK mode

(MOD=1).

• BFREQ is used as the reference frequency for the VCO calibration in OOK mode (MOD=0).

• Calibration occurs every time the VCO is enabled.

• The calibration takes approximately 5s.

The state machine of the calibration is shown in Figure 112.

Figure 112. VCO Calibration State Machine

Count the number of cycles of the VCO

Compare

VCOcount<Targetedcount

VCOband=maxband/2

VCOcount and Targetedcount

Bestband=maxband/2

VCOband=VCOband-Difference

Difference=maxband/4

Difference=Difference/2

VCOband=VCOband+Difference

VCOband=VCOband-Difference

Bestband=VCOband

Difference=1?

YES Bestband is first best band found

or the closest band found

- maxband is the number

of sub-band of the VCO

- Bestband is the band which

is going to be chosen

- Difference is an internal variable.

VCOcount=Targetedcount

VCOcount>Targetedcount

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14 Firmware

This section describes the software subroutines contained in the firmwa re section of the FLASH memory that the user ca n call

for various tasks and to reduce the software development time for the main internal operations.

14.1 Software Jump Table

All subroutines are accessed through a jump table located at the bottom of the firmware FLASH memory as described in Table 86.

This allows upgrades in firmware without changing the software code of the user. All subrou tines should be accessed with the

JSR instruction.

14.2 Function Document ation

The following subsections describe the details of the firmware routines. Further details can be found in the latest version of the

FXTH870xD Embedded Firmware User Guide.

14.2.1 General Rules

1. No output parameter can use the extreme codes (all zero’s or all one’s).

2. The all zero’s output code will always indicate a fault and the status byte will indicate the source of the error.

3. While firmware is processing, CPU resources are unavailabl e for application.

4. Each measured parameter will return a limit code ($00, $FF or $1FF) if an error occurs in its acquisition, except for the

external ADC voltage measurements on the PTA[1:0] pins.

5. External ADC voltage measurements on the PTA[1:0] pins will return a full range code that is ratiometric to the supply

voltage.

14.2.1.1 FXTH870x02 Single Z-axis Firmware Routines

The details on the use and execution of each firmware routine is documented in the CodeW arrior project file that is supplied by

Freescale. Any future updates to these firmware routines will be contained in that file. A summary of the firmware routines

available is given in Table 86.

The firmware table is comprised of 3-byte entries where the first byte is the operational code for the JMP instruction, and the

following two bytes are the absolute address pointing to the location of the firmware fu nction.

Table 86. FXTH870x02 Single Z- axis Firmware Summary and Jump Table

Address Routine Description

E000 TPMS_RESET Master reset of complete device

E003 TPMS_READ_VOLTAGE 10-bit uncompensated bandgap voltage reading

E006 TPMS_COMP_VOLTAGE 8-bit compensation of 10-bit voltage reading

E009 TPMS_READ_TEMPERATURE 10-bit uncompensated temperature reading

E00C TPMS_COMP_TEMPERATURE 8-bit compensation of 10-bit temperature reading

E00F TPMS_READ_PRESSURE 10-bit uncompensated pressure reading

E012 TPMS_COMP_PRESSURE 9-bit compensation of 10-bit pressure reading

E015 TPMS_READ_ACCELERATION 10-bit uncompensa ted acceleration reading

E018 TPMS_COMP_ACCELERATION 9-bit compensation of 10-bit acceleration reading

E01B TPMS_READ_V0 10-bit uncompensated voltage reading on PTA0 pin

E01E TPMS_READ_V1 10-bit uncompensated voltage reading on PTA1 pin

E021 TPMS_LFOCAL LFO clock calibration

E024 TPMS_MFOCAL MFO clock calibration

E027 TPMS_WAVG Weighted average (2, 4, 8, 16 or 32)

E02A TPMS_RF_RESET Master reset of RFM

E02D TPMS_RF_READ_DATA Read RFM data buffer

E030 TPMS_RF_READ_DATA_REVERSE Read RFM data buffer in reverse bit order

E033 TPMS_RF_WRITE_DATA Write RFM data buffer

E036 TPMS_RF_WRITE_DATA_REVERSE Write RFM data buffer in reverse bit order

E039 TPMS_RF_CONFIG_DATA Configure RFM

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14.2.1.2 FXTH870x11 Dual XZ-axis Firmware Routines

The details on the use and execution of each firmware routine is documented in the CodeWarrior project file that is supplied by

Freescale. Any future updates to these firmware routines will be contained in that file. A summary of the firmware routines

available is given in Table 87.

The firmware table is comprised of 3-byte entries where the first byte is the operational code for the JMP instruction, and the

following two bytes are the absolute address pointing to the location of the firmware fu nction.

E03C Reserved Reserved

E03F TPMS_RF_SET_TX Initiate RF transmission

E042 TPMS_RF_DYNAMIC_POWER Adjusts PA for uniform power output

E045 TPMS_MSG_INIT Initialization of the emulated serial communication

E048 TPMS_MSG_READ Reading data from emulated serial interface

E04B TPMS_MSG_WRITE Writing data on emulated serial interface

E04E TPMS_CHECKSUM_XOR Calculates a checksum for given buffer in XOR

E051 TPMS_CRC8 Calculates CRC8 on portion of memory

E054 TPMS_CRC16 Calculates CRC16 on portion of memory

E057 TPMS_SQUARE_ROOT Calculates square root

E05A TPMS_READ_ID Reads device ID stored in FLASH

E05D TPMS_LF_ENABLE Enable/Disable LF for Carrier or Data

E060 TPMS_LF_READ_DATA Reading LF data

E063 TPMS_WIRE_AND_ADC_CHECK Performs checks of internal bond wires

E066 TPMS_FLASH_WRITE Write to FLASH

E069 TPMS_FLASH_CHECK Performs checksum on Freescale firmware FLASH

E06C TPMS_FLASH_ERASE Erases one page (512 bytes) of FLASH at a time

E06F TPMS_READ_DYNAMIC_ACCEL Offsets Z-axis acceleration with one of 15 steps

E072 TPMS_RF_ENABLE Enable RFM

E075 TPMS_FLASH_PROTECTION Lock out FLASH

E078 Reserved Reserved

E07B TPMS_MULT_SIGN_INT16 Multiple two signed 16-bit numbers together

E07E TPMS_VREG_CHECK Verify that external capacitor connected to VREG pin

E081 TPMS_PRECHARGE_VREG Precharge external capacitor on VREG pin

E084 Reserved Reserved

E087 TPMS_READ_ACCEL_CONT_START Enable the TPMS_READ_ACCEL_CONT function.

E08A TPMS_READ_ACCEL_CONT Take continuous acceleration readings and store to assigned location.

E08D TPMS_READ_ACCEL_CONT_STOP Disable the TPMS_READ_ACCEL_CONT function.

Table 87. FXTH870x11 Dual XZ-axis Firmware Summary and Jump Table

Address Routine Description

E000 TPMS_RESET Master reset of complete device

E003 TPMS_READ_VOLTAGE 10-bit uncompensated bandgap voltage reading

E006 TPMS_COMP_VOLTAGE 8-bit compensation of 10-bit voltage reading

E009 TPMS_READ_TEMPERATURE 10-bit uncompensated temperature reading

E00C TPMS_COMP_TEMPERATURE 8-bit compensation of 10-bit temperature reading

E00F TPMS_READ_PRESSURE 10-bit uncompensated pressure reading

E012 TPMS_COMP_PRESSURE 9-bit compensation of 10-bit pressure reading

E015 TPMS_READ_ACCELERATION_X 10-bit uncompensated X-axis accel r eading

Table 86. FXTH870x02 Single Z-axis Firmware Summary and Jump Table (con tinued)

Address Routine Description

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E018 TPMS_READ_DYNAMIC_ACCEL_X 10-bit uncompensated X-axis accel reading

with dynamic offset adjustment.

E01B TPMS_COMP_ACCELERATION_X 9-bit compensation of 10-bit X-axis accel reading

E01E TPMS_READ_ACCELERATION_Z 10-bit uncompensated Z-axis accel reading

E021 TPMS_READ_DYNAMIC_ACCEL_Z 10-bit uncompensated Z-axis accel reading with dynamic offset

adjustment.

E024 TPMS_COMP_ACCELERATION_Z 9-bit compensation of 10-bit Z-axis accel reading

E027 TPMS_READ_ACCELERATION_XZ 10-bit uncompensated X-axis and Z-axis accel readings

E02A TPMS_READ_DYNAMIC_ACCEL_XZ 10-bit uncompensa ted X-axis and Z-axis accel readings with dynamic

offset adjustment.

E02D TPMS_COMP_ACCELERAT ION_XZ 9-bit compen sati on of 10-bit X-axis and Z-axis accel readings

E030 TPMS_READ_V0 10-bit uncompensated voltage reading on PTA0 pin

E033 TPMS_READ_V1 10-bit uncompensated voltage reading on PTA1 pin

E036 T PMS_LFOCAL LF O clock calibration

E039 TPMS_MFOCAL MFO clock calibration

E03C TPMS_RF_ENABLE Enable and set up RFM

E03F TPMS_RF_RESET Master reset of RFM

E042 TPMS_RF_READ_DATA Read RFM data buffer

E045 TPMS_RF_READ_DATA_REVERSE Read RFM data buffer in reverse bit order

E048 TPMS_RF_WRITE_DATA Write RFM data buffer

E04B TPMS_RF_WRITE_DATA_REVERSE Write RFM data buffer in reverse bit order

E04E TPMS_RF_CONFIG_DATA Configure RFM

E051 Reserved Reserved

E054 TPMS_RF_SET_TX Initiate RF transmission

E057 TPMS_RF_DYNAMIC_POWER Adjusts PA for uniform power output

E05A TPMS_MSG_INIT Initialization of the emulated serial communication

E05D TPMS_MSG_READ Reading data from emulated serial interface

E060 TPMS_MSG_WRITE Writing data on emulated serial interface

E063 TPMS_CHECKSUM_XOR Calculates a checksum for given buffer in XOR

E066 TPMS_CRC8 Calculates CRC8 on portion of memory

E069 TPMS_CRC16 Calculates CRC16 on portion of memory

E06C TPMS_SQUARE_ROOT Calculates square root

E06F TPMS_READ_ID Reads device ID stored in FLASH

E072 TPMS_LF_ENABLE Enable/Disable LF for Carrier or Data

E075 TPMS_LF_READ_DATA Reading LF data

E078 TPMS_WIRE_AND_ADC_CHECK Performs checks of internal bond wires

E07B TPMS_FLASH_WRITE Write to FLASH

E07E TPMS_FLASH_CHECK Performs checksum on Freescale firmware FLASH

E081 TPMS_FLASH_ERASE Erases one page (512 bytes) of FLASH at a time

E084 TPMS_FLASH_PROTECTION Lock out FLASH

E087 Reserved Reserved

E08A TPMS_MULT_SIGN_INT16 Multiple two signed 16-bit numbers together

E08D TPMS_WAVG Weighted average

E090 Reserved Reserved

Table 87. FXTH870x11 Dual XZ-axis Firmware Summary and Jump Table (continued)

Address Routine Description

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14.2.2 Device Identification

The bytes assigned to identify the device and its options are descri bed below. These data can be read by use of the

TPMS_READ_ID routine.

ID12:0 — Device ID within each lot, maximum 8,192 per lot

ID13:26 — Assembly lot ID, 100 through 16383

ID27 — Always 0 for FXTH87 family

ID28:31 — Always 0x08 to identify Freescale as supplier

Table 88. Device ID Coding Summary

Address Register

NameBit 7654 321Bit 0

00 CODE0 Reserved - Firmware Revision/Software Information

01 CODE1 ES2 ES1 ES0 PRESS-H ACC1 ACC0 SPCLA PRESS-L

02 CODE2 ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0

03 CODE3 ID15 ID14 ID13 ID12 ID11 ID10 ID9 ID8

04 CODE4 ID23 ID22 ID21 ID20 ID19 ID18 ID17 ID16

05 CODE5 ID31 ID30 ID29 ID28 ID27 ID26 ID25 ID24

Table 89. Device ID Coding Descriptions

Field Description

CODE0

7:0

Reserved Reserved for Freescale firmware description.

CODE1

7:5

Revision number for the multiple-chip-module silicon.

000 - MCU version 0

111 - MCU version 7

CODE1

PRESS-H

Calibrated range for pressure. The range is a combination of this bit and the PRESS-L bit, below.

bit 0 = 0, bit 4 = 0 indicates a 100-450 kPa range

bit 0 = 0, bit 4 = 1 indicates a 100-900 kPa range

CODE1

3:2

ACC

Type of accelerometer.

00 - None

01 - One accelerometer with X-axis orientation

10 - One accelerometer with Z-axis orientation

11 - Two accelerometers with X- and Z-axis orientations

CODE1

Special calibration for accelerometer.

0 = standard -240 to +270 g Z-axis

1 = extended -270 to +400 g Z -axis

CODE1

PRESS-L

Calibrated range for pressure. The range is a combination of this bit and the PRESS-H bit, above.

bit 0 = 0, bit 4 = 0 indicates a 100-450 kPa range

bit 0 = 0, bit 4 = 1 indicates a 100-900 kPa range

CODE2:4

7:0

CODE5

3:0

ID27:0

28-bit serial number for each device. All numbers to be unique with numbering sequence being a sequential counter for each

product type.

CODE5

7:4

ID31:28

4-bit number assigned to vendor type.

If these bits are unspecified as part of the complete FLASH programming by the customer, then these 4 bits are programmed

to binary 1 0 0 0.

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14.2.3 Definition of Signal Ranges

Each measured parameter (pressure, voltage, temperature, acceleration) results from an ADC10 conversion of an analog signal.

This ADC10 result may then be passed by the firmware to the application software as either the raw ADC10 result or further

compensated and scaled for an output between one and the maximum digital value minus one. The minimum digital value of zero

and the maximum digital value are reserved as error codes.

The signal ranges and their significant data points are shown in Figure 113. In this definition the signal source would normally

output a signal between SINLO and SINHI. Due to process, temperature and voltage variations this signal may increase its range

to SINMIN to SINMAX. In all cases the signal will be between the supply rails, so that the ADC10 will convert it to a range of digital

numbers between 0 and 1023. These digital numbers will have corresponding DINMIN, DINLO, DINHI, DINMAX values. The ADC10

digital value is taken by the firmware and compensated and scaled to give the required output code range.

Figure 113. Measurement Signal Range Definitions

Digital input values below DINMIN and above DINMAX are immediately flagged as being out of range and generate error bits and

the output is forced to the 0 value.

Digital values below DINLO (but above DINMIN) or above DINHI (but not DINMAX) will most likely cause an output that would be less

than 1 or greater than 510, respectively. These cases are considered underflow or overflow, respectively. Underflow results will

be forced to a value of 1. Overflow results will be forced to a value of 510.

SENSOR

ANALOG ADC10 RAW

DIGITAL CALCULATED

DIGITAL

(9-BIT EXAMPLE)

(10-BIT CONVERSION)

VOLTAGE

SIGNAL

SOURCE ADC10 FIRMWARE

ROUTINE

511

510

256

1023

512

VDD/2

VDD

SINMAX

SINHI

SINMIN

SINLO

DINMAX

DINHI

DINLO

DINMIN

NORMAL CASE

UNDERFLOW

LOWER ERROR CASE

FORCE

OUTPUT

TO ZERO

CASE

OVERFLOW

CASE

FORCE

OUTPUT

TO 511

UPPER ERROR CASE

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Digital values between DINLO and DINHI will normally produce an output between 1 to 5 10 (for a 9-bit result). In some isolated

cases due to compensation calculations and ro unding the result may be less than 1 or greater than 510, in which case the

underflow and overflow rule mentioned above is used.

14.3 Memory Resource Usage

The firmware uses the top 8192 bytes of the FLASH memory map.

The firmware uses no specific bytes of the RAM but will cause additional stacking of temporary values.

The firmware uses two bytes ($008E and $008F) of the Parameter Registers for global flags for all routines.

Software Stack

The RESET firmware function sets the SP register to the last address in the RAM. The user can change the default stack location

to meet its own application needs.

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15 Development Support

15.1 Introduction

This chapter describes the single-wire BACKGROUND DEBUG mode (BDM), which uses the on-chip BACKGROUND DEBUG

controller (BDC) module.

15.1.1 Features

Features of the BDC module include:

• Single pin for mode selection and background communication s

• BDC registers are not located in the memory map

• SYNC command to determine target communications rate

• Non-intrusive commands for memory access

• ACTIVE BACKGROUND mode commands for CPU register access

• GO and TRACE1 commands

• BACKGROUND command can wake CPU from STOP or WAIT modes

• One hardware address breakpoint built into BD C

• Oscillator runs in STOP mode, if BDC enabled

• COP watchdog disabled while in ACTIVE BACKGROUND mode

15.2 Background Debug Controller (BDC)

All MCUs in the HCS08 Family contain a single-wire BACKGROUND DEBUG interface that su pports in-circuit programming of

on-chip nonvolatile memory and sophisticated non-intrusive debug capabilities. Unlike debug interfaces on earlier 8-bit MCUs,

this system does not interfere with normal application resou r ces. It does not use any user memory or locations in the memory

map and does not share any on-chip perip herals.

BDC commands are divided into two groups:

• ACTIVE BACKGROUND mode commands require that the target MCU is in ACTIVE BACKGROUND mode (the user

program is not running). ACTIVE BACKGROUND mode commands allow the CPU registers to be read or written, and allow

the user to trace one user instruction at a time, or GO to the user program from ACTIVE BACKGROUND mode.

• Non-intrusive commands can be exec uted at any time even while the user’s program is running. Non-intrusive commands

allow a user to read or write MCU memory locations or access status and control registers within the BACKGROUND

DEBUG controller.

Typically, a relatively simple interface pod is used to translate commands from a host computer into commands for the custom

serial interface to the single-wire BACKGROUND DEBUG system. Depending on the development tool vendor, this interface pod

may use a standard RS-232 serial port, a parallel printer port, or some other type of communications such as a universal serial

bus (USB) to communicate between the host PC and the pod. The pod typically connects to the target system with ground, the

BKGD/PTA4 pin, RESET, and sometimes VDD. An open-drain connection to reset allows the host to force a target system reset,

which is useful to regain control of a lost target system or to control startup of a target system before the on-chip nonvolatile

memory has been programmed. Sometimes VDD can be used to allow the pod to use power from the target system to avoid the

need for a separate power supply. However, if the pod is powered separately, it can be connected to a running target system

without forcing a target system reset or otherwise disturbing the running applicatio n program.

Figure 114. BDM Tool Conne c tor

6NO CONNECT 5

NO CONNECT 3

1RESET

BKGD GND

VDD

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15.2.1 BKGD/PTA4 Pin Description

BKGD/PTA4 is the single-wire BACKGROUND DEBUG interface pin. The primary function of this pin is for bidirectional serial

communication of ACTIVE BACKGROUND mode commands and data. During reset, this pin is used to select between starting

in ACTIVE BACKGROUND mode or starting the user’s application program. This pin is also used to request a timed sync

response pulse to allow a host development tool to determine the correct clock freque ncy for BACKGROUND DEBUG serial

communications.

BDC serial communications use a custom serial protocol first introduced on the M68HC12 Family of microcontrollers. This

protocol assumes the host knows the communication clock rate that is determined by the target BDC clock rate. All

communication is initiated and controlled by th e host that drives a high-to - low edge to signal the beginning of each bit time.

Commands and data are sent most significant bit first (MSB first). For a detailed description of the communications protocol, refer

to Section 15.2.2.

If a host is attempting to communicate with a target MCU that has an unknown BDC clock rate, a SYNC command may be sent

to the target MCU to request a timed sync response signal from which the host can determine the correct communication speed.

BKGD/PTA4 is a pseudo-open-drain pin and there is an on-chip pullup so no external pullup resistor is required. Unlike typical

open-drain pins, the external RC time constant on this pin, which is influenced by external capacitance, plays almost no role in

signal rise time. The custom protocol provides for brief, actively driven speedup pulses to force rapid rise times on this pin without

risking harmful drive level conflicts. Refer to Section 15.2.2, for more detail.

When no debugger pod is connected to the 6-pin BDM interface connector, the internal pullup on BKGD/PTA4 chooses normal

operating mode. When a debug pod is connected to BKGD/PTA4 it is possible to force the MCU into ACTIVE BACKGROUND

mode after reset. The specific conditions for forcing ACTIVE BACKGROUND depend upon the HCS08 derivative (refer to the

introduction to this Development Support section). It is not necessary to reset the target MCU to communicate with it through the

BACKGROUND DEBUG interface.

15.2.2 Communication Details

The BDC serial interface requires the external controller to generate a falling edge on the BKGD/PTA4 pin to indicate the start of

each bit time. The external controller provides this falling edge whether data is transmi tted or received.

BKGD/PTA4 is a pseudo-open-drain pin that can be driven either by an external controller or by the MCU. Data is transferred

MSB first at 16 BDC clock cycles per bit (nominal speed). The interface times out if 512 BDC clock cycles occur between falling

edges from the host. Any BDC command that was in progress when this timeout occurs is aborted without affecting the memory

or operating mode of the target MCU system.

The custom serial protocol requires the debug pod to know the target BDC communication clock speed.

The clock switch (CLKSW) control bit in the BDC status and control register allows the user to select the BDC clock source. The

BDC clock source can either be the bus or the alternate BDC clock source.

The BKGD/PTA4 pin can receive a high or low level or transmit a high or low level. The following diagrams show timing for each

of these cases. Interface timing is synchronous to clocks in the target BDC, but asynchronous to the external host. The internal

BDC clock signal is shown for reference in counting cycles.

Figure 115 shows an external host transmitting a logic 1 or 0 to the BKGD/PTA4 pin of a target HCS08 MCU. The host is

asynchronous to the target so there is a 0-to-1 cycle delay from the host-generated falling edge to where the target perceives the

beginning of the bit time. Ten target BDC clock cycles later, the target senses the bit level on the BKGD/PTA4 pin. T ypically, the

host actively drives the pseudo-open-drain BKGD/PTA4 pin during host-to-target transmissions to speed up rising edges.

Because the target does not drive the BKGD/PT A4 pin during the host-to-target transmission period, there is no need to treat the

line as an open-drain signal during this period.

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Figure 115. BDC Host-to-Target Serial Bit Timing

Figure 116 shows the host receiving a logic 1 from the target HCS08 MCU. Because the host is asynchronous to the target MCU,

there is a 0-to-1 cycle delay from the host-generated falling edge on BKGD/PTA4 to the perceived start of the bit time in the target

MCU. The host holds the BKGD/PTA4 pin low long enough for the target to recognize it (at least two target BDC cycles). The

host must release the low drive before the target MCU drives a brief active-high speedup pulse seven cycles after the perceived

start of the bit time. The host should sample the bit level about 10 cycles after it started the bit time.

Figure 116. BDC Target-to-Host Serial Bit Timing (Logic 1)

Figure 117 shows the host receiving a logic 0 from the target HCS08 MCU. Because the host is asynchronous to the target MCU,

there is a 0-to-1 cycle delay from the host-generated falling edge on BKGD/PTA4 to the start of the bit time as perceived by the

target MCU. The host initiates the bit time but the target HCS08 finishes it. Because the target wants the host to receive a logic

0, it drives the BKGD/PTA4 pin low for 13 BDC clock cycles, then briefly drives it high to speed up the rising edge. The host

samples the bit level about 10 cycles after starting the bit time.

EARLIEST START

TARGET SENSES BIT LEVEL

10 CYCLES

SYNCHRONIZATION

UNCERTAINTY

BDC CLOCK

(TARGET MCU)

HOST

TRANSMIT 1

HOST

TRANSMIT 0

PERCEIVED START

OF BIT TIME

OF NEXT BIT

HOST SAMPLES BKGD/PTA4 PIN

10 CYCLES

BDC CLOCK

(TARGET MCU)

HOST DRIVE

TO BKGD/PTA4 PIN

TARGET MCU

SPEEDUP PULSE

PERCEIVED START

OF BIT TIME

HIGH-IMPEDANCE

HIGH-IMPEDANCE HIGH-IMPEDANCE

BKGD/PTA4 PIN R-C RISE

10 CYCLES

EARLIEST START

OF NEXT BIT

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Figure 117. BDM Target-to- Host Serial Bit Timing (Logic 0)

15.2.3 BDC Commands

BDC commands are sent serially from a host computer to the BKGD/PTA4 pin of the target HCS08 MCU. All commands and data

are sent MSB-first using a custom BDC communications protocol. ACTIVE BACKGROUND mode commands require that the

target MCU is currently in the ACTIVE BACKGROUND mode while non-intrusive commands may be issued at any time whether

the target MCU is in ACTIVE BACKGROUND mode or running a user application progra m. Table 90 shows all HCS08 BDC

commands, a shorthand description of their codi ng structure, and the meaning of each command.

Coding Structure Nomenclature

This nomenclature is used in Table 90 to describe the coding stru cture of the BDC commands. Commands beg in with an 8-bit

hexadecimal command code in the host-to-target direction (most signif icant bit first)

/ = separates parts of the command

d = delay 16 target BDC clock cycles

AAAA = a 16-bit address in the host-to-target direction

RD = 8 bits of read data in the target-to-host direction

WD = 8 bits of write data in the host-to-target direction

RD16 = 16 bits of read data in the target-to-host direction

WD16 = 16 bits of write data in the host-to-target direction

SS = the contents of BDCSCR in the target-to-host direction (STATUS)

CC = 8 bits of write data for BDCSCR in the host-to-target direction (CONTROL)

RBKP = 16 bits of read data in the target-to-host direction (from BDCBKPT breakpoint register)

WBKP = 16 bits of write data in the host-to-target direction (for BDCBKPT breakpoint register)

10 CYCLES

BDC CLOCK

(TARGET MCU)

HOST DRIVE

TO BKGD/PTA4 PIN

TARGET MCU

DRIVE AND

PERCEIVED START

OF BIT TIME

HIGH-IMPEDANCE

BKGD/PTA4 PIN

10 CYCLES

SPEED-UP PULSE

SPEEDUP

PULSE

EARLIEST START

OF NEXT BIT

HOST SAMPLES BKGD/PTA4 PIN

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The SYNC command is unlike other BDC commands because the host does not necessarily know the correct communications

speed to use for BDC communications until after it has anal yzed the response to the SYNC command.

To issue a SYNC command, the host:

• Drives the BKGD/PTA4 pin low for at least 128 cycles of the slowest possible BDC clock (The slowest clock is normally the

reference oscillator/64 or the self-clocked rate/64.)

Table 90. BDC Command Summary

Command

Mnemonic Active BDM/

Non-intrusive Coding

Structure Description

SYNC Non-intrusive n/a(1)

1. The SYNC command is a special operation that does not have a command code.

Request a timed reference pulse to determine target

BDC communication speed

ACK_ENABLE Non-intrusive D5/d Enable acknowledge protocol. Refer to Freescale

document order no. HCS08RMv1/D.

ACK_DISABLE Non-intrusive D6/d Disable acknowledge protocol. Refer to Freescale

document order no. HCS08RMv1/D.

BACKGROUND Non-intrusive 90/d Enter ACTIVE BACKGROUND mode if enabled (ignore

if ENBDM bit equals 0)

READ_STATUS Non-intrusive E4/SS Read BDC status from BDCSCR

WRITE_CONTROL Non-intrusive C4/CC Write BDC controls in BDCSCR

READ_BYTE Non-intrusive E0/AAAA/d/RD Read a byte from target memory

READ_BYTE_WS Non-intrusive E1/AAAA/d/SS/RD Read a byte and report status

READ_LAST Non-intrusive E8/SS/RD Re-read byte from address just read and report status

WRITE_BYTE Non-intrusive C0/AAAA/WD/d Write a byte to target memory

WRITE_BYTE_WS Non-intrusive C1/AAAA/WD/d/SS Write a byte and report status

READ_BKPT Non-intrusive E2/RBKP Read BDCBKPT breakpoint register

WRITE_BKPT Non-intrusive C2/WBKP Write BDCBKPT breakpoint register

GO Active BDM 08/d Go to execute the user application program starting at

the address currently in the PC

TRACE1 Active BDM 10/d Trace 1 user instruction at the address in the PC, then

return to ACTIVE BACKGROUND mode

TAGGO Active BDM 18/d Same as GO but enable external tagging (HCS08

devices have no external tagging pin)

READ_A Active BDM 68/d/RD Read accumulator (A)

READ_CCR Active BDM 69/d/RD Read condition code register (CCR)

READ_PC Active BDM 6B/d/RD16 Read program counter (PC)

READ_HX Active BDM 6C/d/RD16 Read H and X register pair (H:X)

READ_SP Active BDM 6F/d/RD16 Read stack pointer (SP)

READ_NEXT Active BDM 70/d/RD Increment H:X by one then read memory byte located

at H:X

READ_NEXT_WS Active BDM 71/d/SS/RD Increment H:X by one then read memory byte located

at H:X. Report status and data.

WRITE_A Active BDM 48/WD/d Write accumulator (A)

WRITE_CCR Active BDM 49/WD/d Write condition code register (CCR)

WRITE_PC Active BDM 4B/WD16/d Write program counter (PC)

WRITE_HX Active BDM 4C/WD16/d Write H and X register pair (H:X)

WRITE_SP Active BDM 4F/WD16/d Write stack pointer (SP)

WRITE_NEXT Active BDM 50/WD/d Increment H:X by one, then write memory byte located

at H:X

WRITE_NEXT_WS Active BDM 51/WD/d/SS Increment H:X by one, then write memory byte located

at H:X. Also report status.

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• Drives BKGD/PTA4 high for a brief speedup pulse to get a fast rise time (This spe edup pulse is typically one cycl e of the

fastest clock in the system.)

• Removes all drive to the BKGD/PTA4 pin so it reverts to high impedance

• Monitors the BKGD/PTA4 pin for the sync response pulse

The target, upon detecting the SYNC request from the host (which is a much longer low time than would ever occur during normal

BDC communications):

• Waits for BKGD/PTA4 to return to a logic high

• Delays 16 cycles to allow the host to STOP driving the high speedup pulse

• Drives BKGD/PTA4 low for 128 BDC clock cycles

• Drives a 1-cycle high speedup pulse to force a fast rise time on BKGD/PTA4

• Removes all drive to the BKGD/PTA4 pin so it reverts to high impedance

The host measures the low time of this 128-cycle sync response pulse and determines the correct speed for subsequent BDC

communications. Typically, the host can determine the correct communication speed within a few percent of the actual target

speed and the communication protocol can easily to lerate speed errors of several percent.

15.2.4 BDC Hardware Breakpoint

The BDC includes one relatively simple hardware breakpoint that compares the CPU address bus to a 16-bit match value in the

BDCBKPT register. This breakpoint can generate a forced breakpoint or a tagged breakpoint. A forced breakpoint causes the

CPU to enter ACTIVE BACKGROUND mode at the first instruction boundary following any access to the breakpoint address.

The tagged breakpoint causes the instruction opcode at the breakpoint address to be tagged so that the CPU will enter ACTIVE

BACKGROUND mode rather than executing that instruction if and when it reaches the end of the instruction queue. This implies

that tagged breakpoints can only be placed at the address of an instruction opcode while forced breakpoints can be set at any

address.

The breakpoint enable (BKPTEN) control bit in the BDC status and control register (BDCSCR) is used to enable the breakpoint

logic (BKPTEN = 1). When BKPTEN = 0, its default value after reset, the breakpoint logic is disabled and no BDC breakpoints

are requested regardless of the values in other BDC breakpoint registers and control bits. The force/tag select (FTS) control bit

in BDCSCR is used to select forced (FTS = 1) or tagged (FTS = 0) type breakpoints.

15.3 Register Definition

This section contains the descriptions of the BDC registers and control bits.

This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to

translate these names into the appropriate absolute addresses.

15.3.1 BDC Registers and Control Bits

The BDC has two registers:

• The BDC status and control register (BDCSCR) is an 8-bit register containing control and status bits for the BACKGROUND

DEBUG controller.

• The BDC breakpoint match register (BDCBKPT) holds a 16-bit breakpoint match address.

These registers are accessed with dedicated serial BDC commands and are not located in the memory space of the t arget MCU

(so they do not have addresses and cannot be accessed by user programs).

Some of the bits in the BDCSCR have write limitations; otherwise, these registers may be read or written at any time. For

example, the ENBDM control bit may not be written wh ile the MCU is in ACTIVE BACKGROUND mode. (This prevents the

ambiguous condition of the control bit forbidding ACTIVE BACKGROUND mode while the MCU is already in ACTIVE

BACKGROUND mode.) Also, the four status bits (BDMACT, WS, WSF, and DVF) are read-only status indicators and can never

be written by the WRITE_CONTROL serial BDC command. The clock switch (CLKSW) control bit may be read or written at any

time.

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15.3.2 BDC Status and Control Register (BDCSCR)

This register can be read or written by serial BDC commands (READ_STATUS and WRITE_CONTROL) but is not accessible to

user programs because it is not located in the normal memory map of the MCU.

76543210

RENBDM BDMACT BKPTEN FTS CLKSW WS WSF DVF

Normal Reset 00000000

Reset in

Active BDM: 11001000

= Reserved

Figure 118. BDC Status and Control Register (BDCSCR)

Table 91. BDCSCR Register Field Descriptions

Field Description

ENBDM

Enable BDM (Permit ACTIVE BACKGROUND Mode) — Typically, this bit is written to 1 by the debug host shortly after the

beginning of a debug session or whenever the debug host resets the target and remains 1 until a normal reset clears it.

0 BDM cannot be made active (non-intrusive commands still allowed)

1 BDM can be made active to allow ACTIVE BACKGROUND mode commands

BDMACT

BACKGROUND Mode Active Status — This is a read-only status bit.

0 BDM not active (user application program running)

1 BDM active and waiting for serial commands

BKPTEN

BDC Breakpoint Enable — If this bit is clear, the BDC breakpoint is disabled and the FTS (force tag select) control bit and

BDCBKPT match register are ignored.

0 BDC breakpoint disabled

1 BDC breakpoint enabled

FTS

Force/Tag Select — When FTS = 1, a breakpoint is requested whenever the CPU address bus matches the BDCBKPT match

tagged. If this tagged opcode ever reaches the end of the instruction queue, the CPU enters ACTIVE BACKGROUND mode

rather than executing the tagged opcode.

0 Tag opcode at breakpoint address and enter ACTIVE BACKGROUND mode if CPU attempts to execute that instruction

1 Breakpoint match forces ACTIVE BACKGROUND mode at next instruction b oundary (address need not be an opcode)

CLKSW

Select Source for BDC Communications Clock — CLKSW defaults to 0, which selects the alternate BDC clock source.

0 Alternate BDC clock source

1 MCU bus clock

WAIT or STOP Status — When the target CPU is in WAIT or STOP mode, most BDC commands cannot function. However,

the BACKGROUND command can be used to force the target CPU out of WAIT or STOP and into ACTIVE BACKGROUND

mode where all BDC commands work. Whenever the host forces the target MCU into ACTIVE BACKGROUND mode, the host

should issue a READ_STATUS command to check that BDMACT = 1 before attempting other BDC commands.

0 Target CPU is running user application code or in ACTIVE BACKGROUND mode (was not in WAIT or STOP mode when

BACKGROUND became active)

1 T arget CPU is in W AIT or STOP mode, or a BACKGROUND command was used to change from WAIT or STOP to ACTIVE

BACKGROUND mode

WSF

WAIT or STOP Failure Status — This status bit is set if a memory access command failed due to the target CPU executing a

WAIT or STOP instruction at or about the same time. The usual recovery strategy is to issue a BACKGROUND command to

get out of WAIT or STOP mode into ACTIVE BACKGROUND mode, repeat the command that failed, then return to the user

program. (Typically, the host would restore CPU registers and stack values and re-execute the WAIT or STOP instruction.)

0 Memory access did not conflict with a WAIT or STOP instruction

1 Memory access command failed because the CPU entered WAIT or STOP mode

DVF

Data Valid Failure Status — This status bit is not used in the MC9S08RA16 because it does not have any slow access

memory.

0 Memory access did not conflict with a slow memory access

1 Memory access command failed because CPU was not finished with a slow memory access

FXTH870xD

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146 Freescale Semiconductor, Inc.

15.3.3 BDC Breakpoint Match Register (BDCBKPT)

This 16-bit register holds the address for the hardware breakpoint in the BDC. The BKPTEN and FTS control bits in BDCSCR

are used to enable and configure the breakpoint logic. Dedicated serial BDC commands (READ_BKPT and WRITE_BKPT) are

used to read and write the BDCBKPT register but is not accessible to user programs because it is not located in the normal

memory map of the MCU. Breakpoints are normally set while the target MCU is in ACTIVE BACKGROUND mode before running

the user application program. For additional information about setup and use of the hardware breakpoint logic in the BDC, refer

to Section 15.2.4.

15.3.4 System Background Debug Force Reset Register (SBDFR)

This register contains a single write-only control bit. A serial BACKGROUND mode command such as WRITE_BYTE must be

used to write to SBDFR. Attempts to write this register from a user program are ignored. Reads always return 0x00.

Figure 119. System Backgrou nd Debug Force Reset Register (SBDFR)

76543210

R00000000

WBDFR(1)

1. BDFR is writable only through serial BACKGROU ND mode debug commands, not from user programs.

Reset 00000000

= Reserved

Table 92. SBDFR Register Fie ld Description

Field Description

BDFR

Background Debug Force Reset — A serial ACTIVE BACKGROUND mode command such as WRITE_BYTE allows an

external debug host to force a target system reset. Writing 1 to this bit forces an MCU reset. T his bit cannot be written from a

user program.

FXTH870xD

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Freescale Semiconductor, Inc. 147

16 Battery Charge Consumption Modeling

The supply current consu med by the FXTH870xD can be estimated using the following basic model.

16.1 Standby Current

The overall charge consumed by the standby features is:

Eqn. 12

where: QSTDBY = Stand by charge ove r li fetime, tTOT, in mA-hr

tTOT = Total lifetime in hours

ISTDBY = General standby current in A

ILF = LFR detector (if used) current in A

16.2 Measurement Events

The overall charge consumed by the measurements is:

Eqn. 13

where: QMEAS = Total measurement charge over lifetime in mA-sec

QPRESS = Measurement charge per pressure measurement in A-sec

QTEMP = Measurement charge per temperature measurement in A-sec

QVOLT = Measurement charge per voltage measurement in A-sec

nPRESS = Total number of pressure measurements over lifetime

nTEMP = Total number of temperature measurements over lifetime

nVOLT = Total number of voltage measurements over lifetime

16.3 Transmission Events

The overall charge consumed by the transmissions is:

Eqn. 14

where: QXMT = Transmit charge over lifetime , tTOT, in mA-hr

QFRM = Transmit charge per frame of data in A-sec

nXMT = Number of transmissions over lifetime

F = Frames transmitted during each datagram

16.4 Total Consumption

The overall charge consumed is:

Eqn. 15

where: QTOT = Total charge over lifetime, tTOT, in mA-hr

QSTDBY = Standby charge over lifetime in mA-hr

QMEAS = Measurement charge over lifetime in mA-hr

QXMT = T ransmit charge over lifetime in mA-hr

Y = Lifetime in years

SD = Battery self-discharge rate in%/year

Additional margin in battery capacity can be added to the calculated value of QTOT.

QSTDBY tTOT

ISTDBY ILF

+

1000

--------------------------------------------

=

QMEAS 1

1000

------------nPRESS QPRESS nTEMP QTEMP nVOLT QVOLT

++=

QXMT

QFRM

1000

----------------- FnXMT

=

QTOT

QSTDBY QMEAS QXMT

++

1 Y SD 100

–

------------------------------------------------------------------------------------

FXTH870xD

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148 Freescale Semiconductor, Inc.

17 Electrical Specifications

17.1 Maximum Ratings

Maximum ratings are the extreme limits to which the device can be exposed without permanently damaging it. The device

contains circuitry to protect the inputs against damage from high static voltages; however , do not apply voltages higher than those

shown in the table below. Keep VIN and VOUT within the range VSS  (VIN or VOUT)  VDD.

Note: Refer to page 167 for description of notes.

17.2 Operating Range

The limits normally expected in the application which define range of operation.

Note: Refer to page 167 for description of notes.

# Rating Symbol Value Unit

100 Supply Voltage (VDD, AVDD)V

DD -0.3 to +3.8 V (3)

101

102

103

104

Input Voltage

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1

BKGD/PTA4, RESET

LFA, LFB

VIN

-0.3 to VDD+0.3

(3)

105

106

107

108

Input Current

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1

BKGD/PTA4, RESET

LFA, LFB

IIN

±10

(3)

109

110

Substrate Current Injection

Current from any pin to VSS - 0.3 VDC

XI, PTA0, PTA1, PTA2, PTA3, PTB0, PTB1, BKGD/PTA4, RESET

LFA, LFB ISUB

ISUB

600

2µA

mA (3)

(3)

111 Latchup Current

Current to/from any pin to supply rails + 0.3 VDC ILATCH ±100 mA (3)

112

113

114

Electrostatic Discharge

Human Body Model (HBM), all pins other than RF

Human Body Model (HBM), RF pin

Charged Device Model (CDM)

VESD

±2000

±3000

±500

(3)

115 Maximum Storage Temperature Range Tstg -50 to +150 °C (3)

# Characteristic Symbol Min Typ Max Units

200

201

202

203

204

205

206

207

Operating Supply Voltage (VDD = AVDD)

Measurements

Pressure, Temperature, Acceleration

Voltage

LFR Operation (-20 < TA< +85 °C)

RF Transmissions

MCU operation (CPU, ADC10, RAM, T PM1)

FLASH write (-40 to +125 °C)

FLASH write (-20 to +85 °C)

FLASH read

Parameter registers data retention

VDD

2.3

1.8

2.3

1.8

2.3

2.1

1.8

1.2

3.0

—

3.6

—

(2)

208

209

Operating Temperature Range

Continuous Tempe rature Range

STOP1 mode (note 5) TA

-40

-40 —

—

+125

+150 °C

°C (3)

(3)

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Freescale Semiconductor, Inc. 149

17.3 Electrical Characteristics

1.8  VDD  3.6, TL  TA  TH, unless otherwise specified.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

300 Output High Voltage (ILoad = 5 mA)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1 VOH VDD-0.35 — — V (2)

301 Output Low Voltage (ILoad = -5 mA)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1 VOL — — 0.35 V (2)

302

303

Input High Voltage (2.3  VDD  VH)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1, BKGD/PTA4

Input High Voltage (VL  VDD  2.3)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1

VIH

0.7 x VDD

0.85 x VDD

—

(2)

(3)

304

305

Input Low Voltage (2.3  VDD  VH)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1, BKGD/PTA4

Input Low Voltage (VL  VDD  2.3)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1

VIL

VSS

—

0.35 x VDD

0.28 x VDD

(2)

(3)

306

307

308

Input High Current (at min VIH)

BKGD/PTA4

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1 (pullup off)

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1 (pullup active)

IIH

-1

-120

—

µA

(2)

309

310

311

Input Low Current (at max VIL)

BKGD/PTA4

PTA0, PTA1, PTA2, PTA3, PTB0, PTB1 (pulldown off)

PTA0, PTA1, PTA2, PTA3 (pulldown active)

IIL

-120

-1

—

+120

µA

(2)

312 Pin Capacitance (3 V)

BKGD/PTA4, PTA0, PTA1, PTA2, PTA3, PTB0, PTB1 C 0 — 15 pF (3)

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150 Freescale Semiconductor, Inc.

17.4 Power Consumption (MCU)

1.8  VDD  3.6, TA 0 to 125 °C unless otherwise specified.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

400

401

402

403

404

405

406

Standby Supply Current

STOP1 mode, LFR, LVD and TR all off

TA = -40 °C, VDD = 3.0 V

TA = 0 °C, VDD = 3.0 V

TA = 25 °C, VDD = 1.8 V

TA = 25 °C, VDD = 3.0 V

TA = 25 °C, VDD = 3.6 V

TA = 70 °C, VDD = 3.0 V

TA = 125 °C, 3.0 V  VDD  3.6 V

ISTDBY1

—

0.5

—

0.9

0.8

0.72

0.9

1.5

µA

(3)

(2)

(3)

407

408

409

410

411

412

Standby Supply Current

STOP4 mode, LFR and TR off, LVD or RFLVD on

TA = -40 °C, VDD = 3.0 V

TA = 0 °C, VDD = 3.0 V

TA = 25 °C, VDD = 1.8 V

TA = 25 °C, VDD  3.0 V

TA = 70 °C, VDD  3.0 V

TA = 125 °C, 3.0 V  VDD  3.6 V

ISTDBY4

—

100

140

µA

(3)

(2)

(3)

413

414

415

416

MCU Operate Current (1.8  VDD  3.0 V , -40 °C  T A  125 °C)

Instruction Speed = 0.333 MIP/fBUS

0.5 MHz fBUS, BUSCLKS[1:0] = 11

1 MHz fBUS, BUSCLKS[1:0] = 10

2 MHz fBUS, BUSCLKS[1:0] = 01

4 MHz fBUS, BUSCLKS[1:0] = 00

IDD

—

0.72

0.94

1.46

2.50

1.0

1.1

1.7

2.9

(3)

(1)

417

418

Standby Current Adder for Temperature Restart

VDD = 1.8 V, TA = 125 °C

VDD = 3.0 V, TA = 125 °C IDD

IDD

—

—10

10 15

15 µA

µA (3)

(3)

419 MCU Wakeup Consumption (+25 °C, 3 V)

From STOP1 to first instruction, fBUS = 4 MHz QWAKE 0 0.05 0.1 µA-sec (3)

420

421

External Battery Model

Series impedance at end-of-life

Open circuit voltage at end-of-life ZEOL

VEOL

—

2.7 —

—60

—

V(4)

(4)

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Freescale Semiconductor, Inc. 151

17.5 Control Timing

1.8  VDD  3.6, TL  TA  TH, unless otherwise specified.

Note: Refer to page 167 for description of notes.

Figure 120. MCU Startup Delays

Figure 121. Control Timing Tes t Load for Digital Pins

# Characteristic Symbol Min Typ Max Units

500

501

502

503

Internal Clock Frequency

Initial startup frequency

Final frequency

Full temperature range, -40 °C to +125 °C

Complete stabilization time (see Figure 120)

fOSCINIT

fOSC

tOSCSU

6.8

—

300

8.1

1000

MHz

sec

(3)

504 MCU Bus Frequency fBUS — 0.5 fOSC —MHz(2)

505 Medium frequency clock (MFO)

Full temperature range, -40 °C to +125 °C fMFO 106 — 128 kHz (3)

506 Low frequency clock (LFO)

Full temperature range, -40 °C to +125 °C fLFO 770 — 1429 Hz (3)

507 LFR clock (derived from LFRO) fLFRO 122 129 135 kHz (1)

508

509

Power-On Reset Response

Supply voltage rise time

Recovery time below VDD = 0.5 V tVDDR

tVDDOFF

—

0—

—1

70 sec

sec (3)

(3)

510

511

MCU Wakeup Time (see Figure 120)

From STOP1 to first instruction, fBUS = 4 MHz

From STOP4 to first instruction, fBUS = 4 MHz tMCUWAKE

tMCUWAKE

—

—50

100 70

155 sec

sec (3)

(3)

512 FLASH Data Retention Time tDR 10 — — year (4)

HFO Clock

STOP1 Wakeup

execute instructions

tOSCSU

tMCUWAKE

HFO = fOSCINIT HFO = fOSC

10.91 k

TEST POINT

VDD

50 pF

6.32 k

FXTH870xD

Sensors

152 Freescale Semiconductor, Inc.

17.6 Voltage Measurement Characteristics

1.8  VDD  3.6, TL  TA  TH, unless otherwise specified.

Note: Refer to page 167 for description of notes

# Characteristic Symbol Min Typ Max Units

600

601

602

Lower LVD detect threshold (note 15)

VDD falling

VDD rising

Voltage drop detection time (note 16)

VLVDL

tLVDL

1.79

1.87

—

1.88

—

1.96

2.03

sec

(2)

(3)

603

604

605

Higher LVD detect threshold (note 15)

VDD falling

VDD rising

Voltage drop detection time (note 16)

VLVDH

tLVDH

2.05

2.12

—

2.3

sec

(2)

(3)

606

607

608

Lower LVW detect threshold (LVWV = 0, note 15)

VDD falling

VDD rising

Voltage drop detection time (note 16)

VLVWL

tLVWL

2.05

2.12

—

2.3

sec

(2)

(3)

609

610

611

Higher LVW detect threshold (LVWV = 1, note 15)

VDD falling

VDD rising

Voltage drop detection time (note 16)

VLVWH

tLVWH

2.28

2.34

—

2.54

2.61

sec

(2)

(3)

612 RF LVD detect threshold, VDD falling (note 15) VLVDRF 1.60 1.79 1.95 V (2)

613 Voltage drop detection time (note 16) tLVDRF ——10sec (3)

614

615

Power-On Reset Voltage (note 15)

Rising Voltage to Recover

Falling Voltage to Reset VPORR

VPORF

—

0.8 —

—2.1

—V

V(3)

(3)

616

617

618

619

620

621

622

623

624

625

Internal Voltage (VDD, monotonic response).

VCODE= 0

= 58

= 88

= 108

= 128

= 158

= 208

= 238

= 255

Voltage sensitivity

VINT

VINT

—

1.6

2.0

2.2

2.4

2.7

3.2

3.5

—

FAULT

1.8

2.1

2.3

2.5

2.8

3.3

3.6

FAULT

—

2.0

2.2

2.4

2.6

2.9

3.4

3.7

—

mV/count

(3)

(1)

(3)

626

627

628

629

External Voltage (PTA[1:0], monotonic response,

conversion is ratiometric to VDD)

GxCODE, where x = 0, 1 refers to PTA0 or PTA1

Voltage sensitivity

ADC INL

ADC DNL

VEXT

INL

DNL

—

-1

1023 (VIN/VDD)

VDD/1023

—

count

V/count

LSB

(4)

(3)

630

631

632

633

634

635

Voltage Measurement

(internal voltage or external pin)

Sensor measurement time (note 7)

Peak current (note 8)

Power consumption (note 22)

Raw measurement, 10-bit

Compensation, 8-bit

Basic compensated reading, 8-bit

Full compensated reading, 8-bit

tVM

—

0.45

3.2

0.13

0.40

0.53

3.9

0.3

0.64

0.9

µA-sec

(3)

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Freescale Semiconductor, Inc. 153

17.7 Temperature Measurement Characteristics

2.3  VDD  3.6, TL  TA  TH, unless otherwise specified.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

700

701

702

703

704

705

706

707

708

709

Temperature measurement (monotonic response) (note 1 1)

TCODE = 0

= 15

= 35

= 55

= 84

= 125

= 140

= 180

= 255

Temper ature sensitivity

T

—

-45

-23

-3

120

—

FAULT

-40

-20

125

FAULT

1.0

—

-35

-17

130

—

°C

°C/count

(3)

(1)

(3)

(1)

(3)

710 Temperature measurement stability range (note 10) TSTAB — — 2 count (3)

711

712

713

714

Thermal Shutdown Recovery (TRE = 1)

High Re-Arming Temperature (TRH = 1, note 13)

High Reset Temperature (TRH = 1)

Low Re-Arming Temperature (TRH = 0, note 13)

Low Reset Temperature (TRH = 0)

TREARMH

TRESETH

TREARML

TRESETL

—

-90

—

118

—

°C

(4)

715

716

717

718

719

720

Temper ature Measurement

Sensor measurement time (note 7)

Peak current (note 8)

Power consumption (note 22)

Raw measurement, 12-bit

Compensation, 8-bit

Basic compensated reading, 8-bit

Full compensated reading, 8-bit

tTM

—

0.6

3.0

0.19

0.43

0.62

0.7

3.9

0.3

0.6

0.82

µA-sec

(3)

FXTH870xD

Sensors

154 Freescale Semiconductor, Inc.

17.8 Pressure Measurement Characteristic (100 to 450 kPa ranges)

2.3  VDD  3.6, TL  TA  TH, unless otherwise specified.

Pressure accuracy specified for pressure drops slower than 1 kPa/sec.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

Pressure Measurement (note 6)

0 °C TA +70 °C

PCODE = 0

= 1

= 10

= 255

= 499

= 510

= 511

-20 °C TA 0 °C, 70 °C TA 85 °C

PCODE = 0

= 1

= 10

= 255

= 499

= 510

= 511

-40 °C TA -20 °C, 85 °C TA 125 °C

PCODE = 0

= 1

= 10

= 255

= 499

= 510

= 511

—

100

268

436

443

—

89.5

96.5

264.5

432.5

439.5

—

83.2

90.2

258.2

426.2

433.2

—

FAULT

100

107

275

443

450

FAULT

100

107

275

443

450

FAULT

100

107

275

443

450

FAULT

—

107

114

282

450

457

—

110.5

117.5

285.5

453.5

460.5

—

116.8

123.8

291.8

459.8

466.8

—

kPa

(3)

(4)

(3)

(4)

(3)

(4)

(3)

(1)

(3)

(4)

(3)

(4)

(3)

(4)

(3)

821 Pressure Sensitivity PRANGE — 0.688 — kPa/count (3)

822 Pressure Measurement Stability Range PSTAB — — 6 count (3)

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Freescale Semiconductor, Inc. 155

17.9 Pressure Measurement Characteristic (100 to 900 kPa Ranges)

2.3  VDD  3.6, TL  TA  TH, unless otherwise specified.

Pressure accuracy specified for pressure drops slower than 1 kPa/sec.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

Pressure Measurement (note 6)

0 °C TA +70 °C

PCODE = 0

= 1

= 10

= 255

= 499

= 510

= 511

-20 °C TA 0 °C, 70 °C TA 85 °C

PCODE = 0

= 1

= 10

= 255

= 499

= 510

= 511

-40 °C TA -20 °C, 85 °C TA 125 °C

PCODE = 0

= 1

= 10

= 255

= 499

= 510

= 511

—

106

491

874

890

—

101

486

869

885

—

477

860

876

—

FAULT

100

116

501

884

900

FAULT

100

116

501

884

900

FAULT

100

116

501

884

900

FAULT

—

110

126

511

894

910

—

115

131

516

899

915

—

124

140

525

908

924

—

kPa

(3)

(4)

(3)

(4)

(3)

(4)

(3)

(1)

(3)

(4)

(3)

(4)

(3)

(4)

(3)

921 Pressure Range PRANGE — 1.572 — kPa/count (3)

922 Pressure Measurement Stability Range PSTAB — — 4 count (3)

923

924

Pressure Sensitivity to Z-Axis Acceleration

(note 12)

0-500g

>500g PACC

PACC

-6.5 —

-4.5 0

-2 Pa/g

Pa/g (3)

(3)

925

926

927

928

929

930

Pressure Measurement

Sensor measurement time (note 7)

Peak current (note 8)

Power consumption (note 22)

Raw measurement, 10-bit

Compensation, 9-bit

Basic compensated reading, 9-bit

Full compensated reading

tPM

—

4.0

3.0

2.1

1.9

4.0

4.4

3.4

3.35

2.3

5.4

6.0

µA-sec

(3)

FXTH870xD

Sensors

156 Freescale Semiconductor, Inc.

17.10 Optional Acceleration Sensor Characteristics

17.10.1 Example Z-Axis Acceleration Sensor Calculations (similar for X-Axis)

As an example, consider that the dynamic firmware routine has returned STEP = 6 indicating offset step 6, and AZCODE = 256.

First, refer to lines 1000 and 1009 to retrieve the step number 6 values for AZCODE = 510 and for AZCODE = 1. Then apply the

following to calculate the sensitivity for offset step 6:

Eqn. 16

Once the sensitivity AZ-6 has been calculated, the acceleration AZ can be calculated with the follow ing transfer function:

Eqn. 17

Another example where STEP has been returned as 15 and AZCODE has been returned as 256:

Eqn. 18

Then:

Eqn. 19

AZ-6 AZ-6 @ AZCODE510 AZ-6 @ AZCODE1–510=

42.1 42.9––510=

0.167g per AZCODE integer=

AZAZ-6 AZCODE AZ-6 @ AZCODE1AZ-6

–+ =

0.167 256 42.9–0.167–+=

=0.3g–

AZ-15 AZ-15 @ AZCODE510 AZ-15

– @ AZCODE1+510=

402 315–510=

0.171g per AZCODE integer=

AZAZ-15 AZCODE AZ-15 @ AZCODE1AZ-15

–+=

0.171 256 315 0.171–+=

= 359g

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 157

17.10.2 Acceleration Measurement Characteristics (Z and X ranges)

2.3  VDD  3.6, TL  TA  TH, unless otherwise specified.

Acceleration accuracy specified for pressure drops slower than 1 kPa/sec.

# Characteristic Symbol FXTH870x02

family (Z-axis) FXTH870x11

family (X-axis) Units

Min Typ Max Min Typ Max Min Typ Max

1000 Acceleration Measurement (note 9)

ACODE = 0 A6— FAULT — — FAULT — — FAULT — g (3)

1001

1002

1003

1004

= 1

= 250

= 256

= 510

-51.9

-4.2

-6

33.0

-42.9

-1

42.1

-33.2

2.1

51.8

See

Offset STEP = 7 See

Offset STEP = 7

(3)

(1)

(3)

1005 = 511 A6— FAULT — — FAULT — — FAULT — (3)

1006 Average Accel Sensitivity (1 to 510 counts) Aaverage — 0.167 — — 0.118 — — 0.039 — g/count (3)

1007 Average Offset step at acceleration output

= 256. VDD = 3 V AINCR 37 39.5 42 — 30 — — 10 — g/Offset

Step (3)

1008 Acceleration measurement stability range

(note 10) ASTAB — — 4 — — 5 — — 4 count (3)

1009

1010

1011

1012

Minimum range of acceleration

measurement for each offset code.

Average Offset STEP= 0

ACODE = 1

= 256

= 510

A0-304

—

-215

-271

-231

-191

238

—

-167

—

-210

-180

-150

—

-80

-70

-60

—

g(3)

1013

1014

1015

1016

Offset STEP = 1

ACODE = 1

= 256

= 510

A1-264

—

-173

-234

-193

-153

-204

—

-133

—

-180

-150

-120

—

-70

-60

-50

—

g(3)

1017

1018

1019

1020

Offset STEP = 2

ACODE = 1

= 256

= 510

A2-223

—

-132

-197

-156

-114

170

—

-150

-120

-90

—

-60

-50

-40

—

g(3)

1021

1022

1023

1024

Offset STEP = 3

ACODE = 1

= 256

= 510

A3-181

—

-88

-158

-117

-75

-136

—

-62

—

-120

-90

-60

—

-50

-40

-30

—

g(3)

1025

1026

1027

1028

Offset STEP = 4

ACODE = 1

= 256

= 510

A4-140

—

-48

-120

-78

-36

-100

—

-24

—

-90

-60

-30

—

-40

-30

-20

—

g(3)

1029

1030

1031

1032

Offset STEP = 5

ACODE = 1

= 256

= 510

A5-88

-45

-2

-81

-39

-74

-33

—

-60

-30

—

-30

-20

-10

—

g(3)

1033

1034

1035

1036

Offset STEP = 6

ACODE = 1

= 256

= 510

A6See lines 1001-1004

in this ‘D’ version —

—

-30

—

-20

-10

—

g(3)

1037

1038

1039

1040

Offset STEP = 7

ACODE = 1

= 256

= 510

A7-10

-5

-14

-4

-10

-6

g(3)

1041

1042

1043

1044

Offset STEP = 8

ACODE = 1

= 256

= 510

A823

—

100

121

—

142

—

g(3)

FXTH870xD

Sensors

158 Freescale Semiconductor, Inc.

Note: Refer to page 167 for description of notes.

1045

1046

1047

1048

Offset STEP = 9

ACODE = 1

= 256

= 510

A961

—

138

118

160

—

183

—

120

—

g(3)

1049

1050

1051

1052

Offset STEP = 10

ACODE = 1

= 256

= 510

A10 97

—

173

115

158

201

133

—

229

—

120

150

—

g(3)

1053

1054

1055

1056

Offset STEP = 11

ACODE = 1

= 256

= 510

A11 134

—

210

155

198

241

176

—

273

—

120

150

180

—

g(3)

1057

1058

1059

1060

Offset STEP = 12

ACODE = 1

= 256

= 510

A12 170

—

246

195

238

281

221

—

317

—

150

180

210

—

g(3)

1061

1062

1063

1064

Offset STEP = 13

ACODE = 1

= 256

= 51

A13 204

—

280

235

279

322

267

—

364

—

180

210

240

—

g(3)

1065

1066

1067

1068

Offset STEP = 14

ACODE = 1

= 256

= 510

A14 240

—

317

275

319

362

310

—

408

—

210

240

270

—

g(3)

1069

1070

1071

1072

Offset STEP = 15

ACODE = 1

= 256

= 510

A15 274

—

350

315

359

402

356

—

455

—

240

270

300

—

g(3)

2.3  VDD  3.6, -20 °C  TA  85 °C, unless otherwise specified.

# Characteristic Symbol All families Units

Min Typ Max

1073 Acceleration cross-axis sensitivity ACROSS -5 — 5 % (4)

1074 Acceleration Sensitivity Variation AZ-15 0 15 % (4)

1075

1076

1077

1078

1079

1080

Z-axis Acceleration Measurement

Sensor measurement time (note 7)

Peak current (note 8)

Power consumption

Raw measurement, 10-bit

Compensation, 9-bit

Basic compensated reading, 9-bit

Full compensated reading, 9-bit,

tAM

—

4.0

3.0

2.1

1.9

4.0

4.4

4.8

3.4

3.6

2.3

6.0

6.2

A-sec

(3)

# Characteristic Symbol FXTH870x02

family (Z-axis) FXTH870x11

family (X-axis) Units

Min Typ Max Min Typ Max Min Typ Max

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 159

17.11 LFR Sensitivity

2.3  VDD  3.6, -20 °C  T A  85 °C, unless otherwise specified. Detection and no detection criteria defined by notes 19 and 20.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

1100

1101

1102

1103

1104

1105

1106

1107

LFR Input Sensitivity in carrier mode, 125 kHz carrier,

LFCDTM = 256 S UOS

Very Low Sensitivity, SENS(1:0) = 00

Detect level, LFA:B

No detect level, LFA:B

Low Sensitivity, SENS(1:0) = 00

Detect level, LFA:B

No detect level, LFA:B

High Sensitivity, SENS[1:0] = 10, CHK125 = 01

Detect level, LFA:B

No detect level, LFA:B

Sensitivity Shift in High Sensitivity,

SENS[1:0] = 10, CHK125 = 00

Detect level, LFA:B

No detect level, LFA:B

SDET_VL

SNODET_VL

SDET_L

SNODET_L

SDET_H

SNODET_H

SDET_H

SNODET_H

—

0.5

—

-0.12

—

3.5

—

mV p-p

(4)

(2)

(3)

1108

1109

LFR Input Sensitivity in data mode

125 kHz carrier, LFCDTM = 64 sec

Valid reception of 10 consecutive frames of 16-bit

Manchester bit preamble + 9T SYNC +16-bit ID + 4 bytes of

data. Continuously ON

High Sensitivity, SENS[1:0] = 10, CHK125 = 01

Data detect level

Data no detect level SPER_H

SNOPER_H

—

0.25 —

—3.5

—mV p-p

mV p-p (2)

(2)

1110

1111

LFR Input Sensitivity in data mode

125 kHz carrier, LFCDTM = 64 sec

Valid reception of 10 consecutive frames of 16-bit

Manchester bit preamble + 9T SYNC +16-bit ID + 4 bytes of

data. Continuously ON

Low Sensitivity, SENS[1:0] = 01, CHK125 = 00

Data detect level

Data no detect level SPER_L

SNOPER_L

—

2—

—14

—mV p-p

mV p-p (3)

(3)

FXTH870xD

Sensors

160 Freescale Semiconductor, Inc.

17.12 LFR Characteristics

2.3  VDD  3.6, -20 °C  TA  85 °C, unless otherwise specified.

Note: Refer to page 167 for description of notes.

17.13 LFR Power Consumption

2.3  VDD  3.6, -20 °C  TA  85 °C, unless otherwise specified. All parameters based upon DEQEN = 0 setting.

Note: Refer to page 167 for description of notes.

# Characteristic Symbol Min Typ Max Units

1200

LF Input Signal Characteristics

Relative to High Sensitivity Data Mode Always Detect, SPER_H

Dynamic Range, DEQEN = 0 VIN 56 — — dB (3)

1201

1202

1203

LFR Input Signal Characteristics

(Manchester Data Mode)

Modulation Depth (Data 1 - Data 0)/Data 1

Data bit time

Bit Duty Cycle

tDATA

MDC

248

—

256

—

100

264

sec

(3)

1204

1205

LFR Differential Input (LFA to LFB, Figure 122)

Differential Resistance

Differential Capacitance (C3)RLFDF

CLFDF

2—

3.8 4

6M

pF (3)

(3)

1206

1207

1208

1209

LFR Carrier Frequency Range

VALEN = 1, LFCDTM = 256 sec

Always accepted carrier

Always rejected carrier, low band limit

Always rejected carrier, high band limit

VALEN = 0, LFCDTM = 256 ms

High Cutoff Freq, 5 mV p-p input, SENS[1:0] = 00

fLFC

121.25

—

210

—

350

128.75

—

kHz

(3)

(4)

1210 LFR Detector Power Up Settling Time (2 LFO cycles) tPU 1.4 2.0 2.6 ms (4)

1211

1212

LFR Preamble Decoder Settling Time

Data Mode Only, LFCDTM plus tDEC

LPSM = 0

LPSM = 1 tDEC

tDEC

—

——

—200

400 sec

sec (4)

(4)

# Characteristic Symbol Min Typ Max Units

1300

1301

1302

1303

1304

1305

LFR Supply Current, Carrier Detect Mode

Monitor for carrier with VALEN = 0, LPSM = 1

TA = 25 °C, 3.0 V VDD

TA = -40 °C to 125 °C, 2.3 to 3.6 V VDD

Frequency validation with

VALEN = 1, LPSM = 1 and CHK125 = 00

TA = 25 °C, 3.0 V VDD

TA = -40 °C to 125 °C, 2.3 to 3.6 V VDD

Frequency validation with

VALEN = 1, LPSM = 1 and CHK125 = 01

TA = 25 °C, 3.0 V VDD

TA = -40 °C to 125 °C, 2.3 to 3.6 V VDD

ILFR

—

3.9

—

5.6

—

5.8

—

5.7

—

7.5

—

8.0

µA

(3)

(1)

1306

1307

LFR Supply Current, Manchester Data Mode

Decoding of data stream after carrier detected

TA = 25 °C, 3.0 V VDD

TA = -40 °C to 125 °C, 2.3 to 3.6 V VDD ILFR

—

—11.8

——

13.5 µA (3)

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 161

Figure 122. LFR Detector Input Equivalent Circuit

–

VAS

VLFIN

ZSPad

leakage

due to

input

protection

SIMPLIFIED

INPUT PIN EQUIVALENT

CIRCUIT

RADIN

Input

SIMPLIFIED

CHANNEL SELECT

CIRCUIT

Pad

leakage

due to

input

protection RADIN

SIMPLIFIED

CHANNEL SELECT

CIRCUIT

Amplifier

, C

LCR

Recommended RC < 15.3 sec

LFA

LFB

RLFDF

CLFDF

FXTH870xD

Sensors

162 Freescale Semiconductor, Inc.

17.14 RF Output Stage

1.8  VDD  3.6, TL  TA  TH, unless otherwise specified.

Power output based on using Dynamic RF Power Correction firmware routine.

Output load of 50  resistance as shown in Figure 125 unless otherwise specified.

MCU in STOP1 mode during all RF tests.

RF output will shutdown when the total RF IDD causes VDD to fall below 1.8 V (VDD = VBATT - IBATT x RBATT). See Figure 126.

# Characteristic Symbol Min Typ Max Units

1400

1401

Nominal Output Power with 50  matching network

(note 21)

315 MHz, TA = 25 °C, VDD = 3 V, PWR[4:0] = 01110

434 MHz, TA = 25 °C, VDD = 3 V, PWR[4:0] = 01111 PRF

PRF

4.0

3.5 5.2

4.9 6.0

6.0 dBm

dBm (1)

(1)

1402*

Nominal Output Power with 50  matching network

at maximum power step, PWR[4:0] = 10100.

Temperature and voltage range defined

by Figure 123 and Figure 124.P

RF 3——dBm(3)

1403

1404

1405

Programmable Power Adjustment

PWR[4:0] = 00000 through 11111

Low Power Mode (PWR[4:0] = 00000)

Range (nominal, (PWR[4:0] > 00000)

Adjustment step (-1.5 to +8 dBm))

PLPM

PRF

PADJ

—

-1.5

—

-10

—

0.5

—

8.0

—

dBm

(3)

1406

Programmable Frequency Steps

Carrier & FSK Deviation

(AFREQ[12:0] and BFREQ[12:0]) fSTEP — 3.174 — kHz (3)

1407 External Crystal Frequency (note 14) fXTAL — 26.000 — MHz (3)

1408 Fixed portion of RF start process tS-RCTS — — 300 sec (3)

1409 Variable portion of RF start process Bits — 3 — bit times (4)

1410 Total RF transmit start time from write of SEND bit to start of

RF @ 2,000 bps, tRF = tS-RCTS + (Bits * bps-1)tRF2 — — 1.8 msec (3)

1411 Total RF transmit start time from write of SEND bit to start of

RF @ 9,600 bps, tRF = tS-RCTS + (Bits * bps-1)tRF9.6 — — 613 sec (3)

1412 Total RF transmit start time from write of SEND bit to start of

RF @ 20,000 bps, tRF = tS-RCTS + (Bits * bps-1)tRF20 — — 450 sec (3)

1413 OOK Modulation Depth MOOK 50 — — dBc (3)

1414 Manchester Encoding Data Rate

Bit Rate Dependent on accuracy of MFO (note 18). DR — — ±5 % (3)

1415 Modulation Duty-Cycle (OOK and FSK) DC 45 50 55 % (3)

1416 XTAL Oscillator Margin (over 26 MHz) (note 17) ML 600 — — (4)

1417

1418

Harmonic 2 Level (315 and 434 MHz bands, with matching

reference network)

VDD = 3 V, TA = 25 °C, PWR[4:0] = 01110

1.8  VDD  3.6, TL  TA  TH, power step adjusted to

reach the targeted power in each domain

H2 —

—-35

-25 -22

-20 dBc

dBc (3)

(3)

1419

1420

Harmonic 4 Level and above (315 and 434 MHz bands, with

matching reference network)

VDD = 3 V, TA = 25 °C, PWR[4:0] = 01110

1.8  VDD  3.6, TL  TA  TH, power step adjusted to

reach the targeted power in each domain

H4 —

——

—-30

-30 dBc

dBc (3)

(3)

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 163

Note: Refer to page 167 for description of notes.

* Freescale critical parameter.

1421

1422

Harmonic 3 Level (315 and 434 MHz bands, with matching

reference network)

VDD = 3 V, TA = 25 °C, PWR[4:0] = 01110

1.8  VDD  3.6, TL  TA  TH, power step adjusted to

reach the targeted power in each domain

H3 —

—-31

-27 -28

-25 dBc

dBc (3)

(3)

1423

1424

1425

1426

1427

1428

1429

1430

Noise for BOOST = 0

Phase Noise (315 MHz)

fRF  10 kHz

fRF  100 kHz

fRF  1 MHz

Phase Noise (434 MHz)

fRF  10 kHz

fRF  100 kHz

fRF  1 MHz

Spurious Noise (315 and 434 MHz bands)

fRF fREF

Occupied Bandwidth (Korea, MIC 2007-63)

For FSK up to 45 kHz and 9600 bit/sec and

for OOK up to 9600 bit/sec

Analyzed setup: RBW = VBW up to 10 kHz,

Span up to 1.25 MHz, and MaxHold

NPH

NSPUR

OBWK

—

-86

-92

-84

-89

-82

-45

—

-78

-86

-82

-76

-83

-80

-40

180

dBc/Hz

dBc

kHz

(3)

1431

1432

1433

1434

1435

1436

Noise for BOOST = 1

Phase Noise (315 MHz)

fRF  10 kHz

fRF  100 kHz

fRF  1 MHz

Spurious Noise (315 MHz bands)

fRF fREF

Occupied Bandwidth (Japan, ARIB STD-T93)

For FSK up to 45 kHz and 9600 bit/sec

For OOK up to 9600 bit/sec

Analyzed setup: RBW = VBW up to 30 kHz,

Span up to 3.5 MHz, and MaxHold

NPH

NSPUR

OBWJ

—

-75

-80

-95

-45

—

-67

-76

-93

-40

400

600

dBc/Hz

dBc

kHz

(3)

1437 RF Oscillator Frequency Accuracy, XCO (note 21)

excluding external crystal and component variations fXCO -30 — +30 ppm (3)

# Characteristic Symbol Min Typ Max Units

FXTH870xD

Sensors

164 Freescale Semiconductor, Inc.

17.15 Power Consumption RF Transmissions

1.8  VDD  3.6, TA 25 °C unless otherwise specified .

Note: Refer to page 167 for description of notes.

Using the TPMS_RF_DYNAMIC_POWER firmware routine (see Section 14) allows adjusting power step in order to compensate

variations of output power versus temperature and voltage. This routine will be associated to a part to part trimming that initially

adjusts the power step to compensate for process variations.

Both these trim and look-up table allow to guarantee by characterization the typical values of power consumption as presented

below (average values among 100 parts plus improvements prediction from design).

Figure 123. Dynamic Power Adjustment - 315 MHz

# Characteristic Symbol Min Typ Max Units

1500

1501

1502

1503

1504

1505

1506

1507

1508

RF Supply Transmission Current

VDD = 3.0 V, PWR[4:0] set for nominal 5 dBm

315 MHZ Power delta for BOOST = 1

315 MHZ Carrier Frequency, BOOST = 0

Data 1, FSK or OOK

434 MHZ Carrier Frequency, BOOST = 0

Data 1, FSK or OOK

Interframe period, IFPD = 0.

Interframe period, IFPD = 0, 1.8 VDD 3.6,

TL  TA  TH

Interframe period, IFPD = 1, DRLPEN = 1,

1.8 VDD 3.6, TL  TA  TH

Interframe period, IFPD = 1, DRLPEN = 0

Interframe period, IFPD = 1, DRLPEN = 0,

1.8 VDD 3.6, TL  TA  TH

IDD

IDD

—

6.0

6.6

617

—

0.55

7.0

7.6

696

789

125

A

(2)

(1)

(3)

(1)

(3)

3dBm

5dBm

-40°C 125°C

25°C 60°C0°C

1.8V

2.5V

3.6V

3dBm

5.3mA 5.5mA

5.3mA 5.5mA 6mA 6.2mA

6.6mA6.3mA

5.8mA

5.7mA

6mA

3dBm

5dBm

-40°C 125°C

25°C 60°C0°C

1.8V

2.5V

3.6V

3dBm

5.3mA 5.5mA

5.3mA 5.5mA 6mA 6.2mA

6.6mA6.3mA

5.8mA

5.7mA

6mA

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 165

Figure 124. Dynamic Power Adjustment - 434 MHz

Figure 125. RF Output Power Measurement Configuration

Figure 126. Batter y Performance Test Configuration

3dBm

5dBm

1.8V

2.5V

3.6V

3dBm

3dBm .

6.3mA 6.5mA

5.5mA 5.7mA 6.7mA 6.8mA

7.8mA

7.1mA

6.4mA

6.8mA

6.6mA

-40°C 125°C

25°C 60°C0°C

3dBm

5dBm

1.8V

2.5V

3.6V

3dBm

3dBm .

6.3mA 6.5mA

5.5mA 5.7mA 6.7mA 6.8mA

7.8mA

7.1mA

6.4mA

6.8mA

6.6mA

-40°C 125°C

25°C 60°C0°C

FXTH870xxx

VDD

RVSS

100 pF 100 nF

1 nF

50 

AVDD

AVSS

FXTH870xxx IBATT

1 F

2.7V

RBATT VBATT

FXTH870xD

Sensors

166 Freescale Semiconductor, Inc.

18 Mechanical Specifications

18.1 Maximum Ratings

Maximum ratings are the extreme limits to which the device can be exposed without permanently damaging it. The device

contains circuitry to protect the inputs against damage from high static voltages; however , do not apply voltages higher than those

shown in the table below. Keep VIN and VOUT within the range VSS  (VIN or VOUT)  VDD.

Note: Refer to page 167 for description of notes.

18.2 Media Compatibility

Media compatibility is based on media and test method described in Freescale specification 12MWS10081G, Media Test for

TPMS MCM Automotive Pressure Sensors. Consult your sales representative for more details and specific requirements.

18.3 Mounting Recommendations

The package should be mounted with the pressure port pointing away from the axis of tire rotation so that centrifugal force wil l

propel any contaminants out of the pressure port. In cases where the application must orient the pressure port pointing inward,

care must be taken to assure contaminants do not reach inside the pressure port.

A plugged port will exhibit no change in pressure and can be cross checked in the user’s software using the method described

in Section 10.1.

Please refer to application note AN1902 for proper printed circuit board attributes and recommendations.

# Rating Symbol Value Unit

1800

1801

Maximum Pressure (absolute)

Continuous

Pulsed, 5 seconds, 25 °C pmax

pmax

1500

2000 kPa

kPa (3)

(3)

1802 Centrifugal Force Effects (Z-axis)

Sustained acceleration (Z-axis) gCENT 2600 g (3)

1803 Powered Shock (peak, 0.1 ms, half-sine, 6-axis) gshock 6000 g (3)

1804 Drop Test (onto concrete, unpowered) hDROP 1.2 m (3)

1805

1806

Pressure Sensor Resonance

Resonant frequency

Damping Ratio fP0

5.5

1MHz (4)

(4)

1807

1808

1809

Optional X-axis Accelerometer Sensor Resonance

Resonant frequency (no-peak, over-damped)

Damping Ratio

Maximum acceleration before limit stops are reached

fX0

gMAX

12.5

0.1

180

kHz

(4)

1810

1811

1812

Optional Z-axis Accelerometer Sensor Resonance

Resonant frequency (no-peak, over-damped)

Damping Ratio

Maximum acceleration before limit stops are reached

fZ0

gMAX

800

kHz

(4)

1813 Package Weight w 0.30 gm (3)

FXTH870xD

Sensors

Freescale Semiconductor, Inc. 167

Notes:

1. Parameters tested 100% at final test.

2. Parameters tested 100% at unit probe.

3. Verified by characterization, not tested in production.

4. For information only, may be determined by simulation.

5. Total of three hours over the life of the device.

6. Fully compensated pressure reading using TPMS_READ_PRESSURE followed by TPMS_COMP_PRESSURE

routine with single reading and 500 Hz low-pass filter ON.

7. Measurement times for one complete compensated reading; and times dependent on clock tolerances.

8. Peak currents measured as the current over 10 MCU bus cycles immediately after the ADC wakes up the MCU

using the external network shown in Figure 126 with RBATT equal to zero-ohm resistance.

9. Fully compensated acceleration reading using TPMS_READ_ACCELERATION followed by

TPMS_COMP_ACCELERATION routine with single reading and 500 Hz low-pass filter ON.

10. Total range of variation over 30 conse cutive measurements, using compensated output format.

11. Temperature error for MCU or RFM powered up at less the 10% duty-cycle

12. Package mounted with pressure port facing radially outward from axis of rotation.

13. Temperature shutdown points trimmed at final test.

14. Suggested crystal is NDK NX3225SA, 26 .000 MHz.

15. Low voltage detectio n and warning thresholds define d for voltage change rates less than 20 mV/s. Hysteresis

thresholds may decrease abo ve 85 °C.

16. Response time to VDD of more than 100 mV below the minimum VDD falling threshold.

17. Crystal oscillator margin is the value of the total series resistance including the XTAL ESR, that can be ap plied

before the XCO does not start up. This definition does not define any specific start up time.

18. Accuracy of the RF data rate when using the data buffer buffer is dependent on the overall oscillator function (i.e.

including external crystal and internal circuit tolerances).

19. LFR detection is tested to assure > 90% message success rate. LFR no detection is tested to assure < 10%

message success rate. In carrier detect mode the applied input pulse is at least 2x the LFCDTM selected. In all

cases the envelop of the input waveform must have a RC time constant less than 15.3 sec. LF sensitivity limits

are measured while the device is in the STOP1 mode, whic h is characterized as a w orst-case condition; sensi-

tivity in the other modes are improved versus the STOP1 modes.

20. Using firmware release $28 or higher.

21. Actual final test value degraded by losses in the tester . Correlation study done as characterization to infer actual

value.

22. Power consumption values refer to the firmware data flow in Figure 57. The BASIC Compensated value includes

just the raw measurement and compensation routine for that parameter. Other raw readings needed for full com-

pensation will be pulled from the UUMA. The FULL Compensated value includes taking all required raw read-

ings and using the compensation routine for that parameter.

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19 Package Outline

Figure 127. QFN Case Outline

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Figure 128. QFN Case Outline

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Figure 129. QFN Case Outline

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20 Revision History

Rev. 0, 05/20 14

• Initial data sheet.

Rev. 1, 05/20 14

• Corrected Ordering Information table.

• Figure 5: Updated paragraph in figure to include PCB traces for the LFA/LFB.

• Section 5.4: Updated register figure to include TRO bit on Bit 0. Added Description to Table 19 and update reserved bit fields.

• Section 6.1: Updated last paragraph in section.

• Section 10.1: Added NOT E .

• Section 10.4: Added NOT E .

• Section 14.2.2: Added definitions for ID codes.

• Section 17.5: Added ro ws 510 and 511, renumbering 510 to 512.

• Section 17.10.2: Change d column content reference from See lines 1042-1045 to See Offset STEP = 7. Change column

content reference See lines1001-1009 to See lines 1001-1004 in this ‘D’ version.

• Section 17.12: Updated Characteristic and Min V alue for line 1200. Updated Characteristic and note reference for line 1210.

Rev. 1.1, 07/2 0 14

• Section 17.4: Update d Symbols for lines 400 through 412 and lines 417 and 418. Updated Max val ue for line 403

• Section 17.6: Updated Max value for line 612 and updated note reference and Symbol for line 613.

• Section 17.7: Updated note references for lines 711-714.

• Section 17.9: Updated Typ and Max values for line 924. Updated Ty p values for lines 927 through 930.

• Section 17.10.2: Deleted lin e 1073 and updated Typ values for lines 1078 through 1081.

• Section 17.11: Deleted lines 1108-1113, duplicated information. Updated Typ value for line 1106.

• Section 17.12: Updated Symbols for lines 1208 through 1210 and updated Characteristics for lines 1208 and 1209.

• Section 17.13: Updated Max value for line 1301.

• Section 18.1: Update d Max value for line 1800.

Rev. 1.2, 09/2 0 14

• First page: Updated bullet “Six multipurpose GPIO pins” to “Seven multipurpose GPIO pins” and subbullets.

• Section 2.3.8: Updated paragraph with additional content.

• Section 2.3.9: Updated title and paragraphs with corrected pin numbers and added text to paragraph.

• Section 2.3.12: Updated content in paragraph.

• Section 3.5.4: Updated header title for I/O Pins, deleted (Optional PTA[3:0]).

• Section 4.3: Table 3, updated Bit contents for Address columns $0000 and $0003.

• Section 5.11.2: Table 26, updated Description for BKGDPE Field

• Section 6: Updated content in first two paragraphs. Updated Figure 29, added boxes and note for emphasis on PTA[3:0]

usage. Updated title and column heads in Table 32 and added rows for PTBPE and PTBDD . Figure 31 and Table 34,

updated Bit 4 to Reserved and updated Field name. Figure 32 and Table 35, updated Bit 4 to Reserved and updated Fi eld

name. Updated first paragraph in Section 6.5.

• Section 7: Section 7.1: Updated 1st bullet. Section 7.2.1: Updated content in first paragraph. Section 7.5: Updated bulleted

text. Sections 7.5.2 and 7.5.3: Updated tables and figures to show bits reserved for firmware or factory test. Section 7.6:

Updated content in second paragraph. Section 7.6.3: Updated content in paragraph. Section 7.6.4: Updated list number 3

and 4.

• Section 12.17.1: Updated LF Enable description in Table 59.

• Section 12.17.4: Table 62, removed “Use Software polling” fro m LFCDIE and LF IDIE Descriptions.

• Section 12.17.8: Added Note after Table 67 regarding setting the CHK125 bits and updated Description for Field 1-0,

CHK125[1:0].

• Section 14.2.1.1: Table 86, changed Routine and Description columns for E084 to Reserved. T able 87, changed Routine and

Description columns for E090 to Reserved.

• Section 17.1: Added Value to line 108.

• Section 17.3: Updated Characteristic for line 311.

• Section 17.12: Updated Min and Max values for line 1206 and up dated Characteristic.

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Rev. 1.2, 09 /2 0 14 (con ti nu e d)

• Section 17.4: Updated Characteric for line 412.

• Section 17.6 Updated Value for line 631.

• Section 17.8: Added asterick notes to lines 821 and 822.

• Section 17.9: Added asterick notes to lines 921 and 922.

• Section 17.13: Updated introduction paragraph.

• Section 17.14: Added asterick note to line 1402 . Redefined lines 1408 through 1411 and added line 1412.

• Section 17.15: Updated Char acteristic for line 1500. Updated Typ value for line1505.

• Section 18.1: Updated Value for line 1802.

• Notes page: Updated Notes 2, 18,19, 20 and added note 25.

Document Number: FXTH870xD

Rev. 1.2

09/2014

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