DF6808 - Digital Core Design

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8-bit FAST Microcontrollers Family

ver 1.04

OVERVIEW

Document contains brief description of

DF6808 core functionality. The DF6808 is a

advanced 8-bit MCU IP Core with highly so-

phisticated, on chip peripheral capabilities.

DF6808 soft core is binary-compatible with the

industry standard 68HC08 8-bit microcontrol-

ler and can achieve a performance 45-100

million instructions per second. There are

two configurations of DF6808: Harvard where

data and program buses are separated, and

von Neumann with common program and

data bus DF6808 has FAST architecture that

is 3.2 times faster compared to original im-

plementation. Core in standard configuration

has integrated on chip major peripheral func-

tion.

The DF6808 Microcontroller Core contains

full-duplex UART (Asynchronous serial com-

munications interface (SCI), and Synchronous

Serial Peripheral Interface SPI.

The main 16-bit, free-running timer system

has implemented two input capture lines and

two output-compare lines.

Self-monitoring circuitry is included on-chip to

protect against system errors. A computer

operating properly (COP) watchdog system

protects against software failures. An illegal

opcode detection circuit provides a non-

maskable interrupt if illegal opcode is de-

tected.

Two software-controlled power-saving modes,

WAIT and STOP, are available to conserve

additional power. These modes make the

DF6808 IP Core especially attractive for

automotive and battery-driven applications.

DF6808 is fully customizable, which means

it is delivered in the exact configuration to

meet users requirements. There is no need to

pay extra for not used features and wasted

silicon. It includes fully automated testbench

with complete set of tests allowing easy

package validation at each stage of SoC de-

sign flow.

CPU FEATURES

FAST architecture, 3.2 times faster than

the original implementation

Software compatible with industry standard

68HC08

Configurable Harvard or Von Neumann

architectures

64 bytes of System Function Registers

space (SFRs)

Up to 64 k bytes of Program Memory

Up to 64k bytes of Data Memory

De-multiplexed Address/Data Bus to allow

easy connection to memory

Two power saving modes: STOP, WAI

Ready pin allows Core to operate with slow

program and data memories

Fully synthesizable, static synchronous

design with no internal tri-states

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ONE GLOBAL SYSTEM CLOCK

No internal reset generator or gated clock

Scan test ready

Technology independent HDL source code

Core can be fully customized

800 MHz virtual clock frequency compared

to original implementation

DESIGN FEATURES

SYNCHRONOUS RESET

ALL ASYNCHRONOUS INPUT SIGNALS ARE

SYNCHRONIZED BEFORE INTERNAL USE

9 DATA MEMORY:

The DF6808 can address up to 64K

bytes of Data Memory. The lowest 64

Bytes is reserved for Special Function Reg-

isters area. Data Memory can be imple-

mented as synchronous or asynchronous

RAM

9 S

YSTEM FUNCTION REGISTERS:

Up to 64 System Function Regis-

ters(SFRs) may be implemented in the

DF6808 design.

9 PROGRAM MEMORY:

Up to 64kB of Program Memory may be

implemented to the DF6808 design. Pro-

gram Memory can be implemented as syn-

chronous or asynchronous ROM.

9 ALL CORE IS DESIGNED AS SYNCHRONOUS

LOGIC WITHOUT ANY MICROCODE.

PERIPHERALS

The peripherals listed below are implemented

in standard configuration of DF6808.

DoCDTM on Chip Debugger

Processor execution control

Read, write all processor contents

Hardware execution breakpoints

Three wire communication interface

Four 8-bit I/O Ports

Interrupt Controller

7 interrupt sources

7 priority levels

Dedicated Interrupt vector for each interrupt

source

Main16-bit timer/counter system

16 bit free running counter

Timer clocked by internal sou rce

16-bit Compare/Capture Unit

Two independent input-capture function s

Two output-compare channels

Events capturing

Pulses generation

Digital signals generatio n

Gated timers

Sophisticated comparator

Pulse width modulation

Pulse width measuring

SPI – Master and Slave Serial Peripheral

Interface

Supports speeds up ¼ of system clock

Software selectable polarity and phase of se-

rial clock SCK

System errors detection

Allows operation from a wide range of system

clock frequencies (build-in 5-bit timer)

Interrupt generation

Full-duplex UART - SCI

Standard Nonreturn to Zero format (NRZ)

8 or 9 bit data transfer

Integrated baud rate generator

Noise, Overrun and Framing error detection

IDLE and BREAK characters generation

Wake-up block to recognize UART wake-up

from IDLE condition

Three SCI related interrupts

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DELIVERABLES

Source code:

VHDL Source Code or/and

VERILOG Source Code or/and

Encrypted, or plain text EDIF

VHDL & VERILOG test bench environ-

ment

Active-HDL automatic simulation macros

ModelSim automatic simulation macros

Tests with reference responses

Technical documentation

Installation notes

HDL core specification

Datasheet

Synthesis scripts

Example application

Technical support

IP Core implementation support

3 months maintenance

● Delivery the IP Core updates, minor

and major versions changes

● Delivery the documentation updates

Phone & email support

LICENSING

Comprehensible and clearly defined licensing

methods without royalty fees make using of IP

Core easy and simply.

Single Design license allows use IP Core in

single FPGA bitstream and ASIC implementa-

tion.

Unlimited Designs, One Year licenses allow

use IP Core in unlimited number of FPGA bit-

streams and ASIC implementations.

In all cases number of IP Core instantiations

within a design, and number of manufactured

chips are unlimited. There is no time restric-

tion except One Year license where time of

use is limited to 12 months.

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○

Single Design license for

VHDL, Verilog source code called HDL Sour-

○ Encrypted, or plain text EDIF called Netlist

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One Year license for

Encrypted Netlist only

Unlimited Designs license for

HDL Source

Netlist

Upgrade from

HDL Source to Netlist

Single Design to Unlimited Desi gns

CONFIGURATION

The following parameters of the DF6808 core

can be easy adjusted to requirements of

dedicated application and technology. Con-

figuration of the core can be prepared by ef-

fortless changing appropriate constants in

package file. There is no need to change any

parts of the code.

- used

•

DoCDTM Hardware Debugger - unused

- Harvard

•

Architecture type - Von Neumann

- Synchronous

•

Memories type - Asynchronou

- used

•

Data Memory wait-states - unused

- used

•

Power saving STOP mode - unused

- used

•

WATCHDOG Timer - unused

- used

•

Timer system - unused

- used

•

Compare Capture channels - unused

- used

•

PORTS A, B, C, D - unused

- used

•

SCI – UART Interface - unused

- used

•

SPI Interface - unused

- used

•

Support for DIV Instructions - unused

- used

•

Support for MUL Instruction - unused

- used

•

Support for DAA Instruction - unused

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PINS DESCRIPTION

PIN ACTIVE TYPE DESCRIPTION

clk - input Global system clock

rst Low input Global system reset

prgdata[7:0] - input Program memory bus input

datai[7:0] - input Memory bus input

ufrdatai[7:0] - input UFRs data bus input

ready Low input Code and Data memory Ready

irq * input Interrupt input

portai[7:0] - input Port A input

portbi[7:0] - input Port B input

portci[7:0] - input Port C input

portdi[7:0] - input Port D input

cap1,2 Low input Capture inputs

rxd Low input SCI receiver data input

si High input SPI slave input

mi High input SPI master input

scki * input SPI clock input

ss Low input SPI slave select

clkdocd - input DoCDTM clock input

docddatai - input DoCDTM serial Data input

prgaddr[15:0] - output Program memory address bus

prgoe - output Program memory output enable

datao[7:0] - output Data memory & UFR bus output

addr[15:0] - output Data memory address bus

ramwe Low output Data memory write enable

ramoe Low output Data memory output enable

ufraddr[5:0] - output UFR’s address bus

ufrwe Low output UFRs write enable

ufroe Low output UFRs output enable

halt High output Halt clock system (STOP inst.)

portao[7:0] - output Port A output

portbo[7:0] - output Port B output

portco[7:0] - output Port C output

portdo[7:0] - output Port D output

ddra[7:0] - output Port A data direction control

ddrb[7:0] - output Port B data direction control

ddrc[7:0] - output Port C data direction control

ddrd[7:0] - output Port D data direction control

cmp1,2 * output Compare outputs

txd Low output SCI transmitter data output

so High output SPI slave output

mo High output SPI master output

scko * output SPI clock output

sckz High output Disconnect SPI clock output

docddatao - output DoCDTM Serial Data Output

docdclk - output DoCDTM Serial Clock Output

prgwe - output DoCDTM Program Memory Write

* Kind of activity is configurable

SYMBOL

addr(15:0)

ramwe

ramoe

portao(7:0)

portdo(7:0)

portco(7:0)

portbo(7:0)

portai(7:0)

portbi(7:0)

portci(7:0)

portdi(7:0)

datai(7:0)

ufrdatai(7:0)

irq

cap1

cap2

clk

rst

rxd

datao(7:0)

txd

halt

ddra(7:0)

ddrd(7:0)

ddrc(7:0)

ddrb(7:0)

cmp1

cmp2

prgdata(7:0) prgaddr(15:0)

prgoe

ready

ufraddr(5:0)

ufrwe

ufroe

clkdocd

docddatai

docddatao

docdclk

prgwe

DoCD

Interface

scki scko

sckz

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BLOCK DIAGRAM

Control Unit - Performs the core synchroniza-

tion and data flow control. This module man-

ages execution of all instructions. The Control

Unit also manages execution of STOP instruc-

tion and wakes-up the processor from the

STOP mode.

Opcode Decoder - Performs an instruction

opcode decoding and the control functions for

all other blocks.

ALU - Arithmetic Logic Unit performs the

arithmetic and logic operations during execu-

tion of an instruction. It contains accumulator

(A), Condition Code Register (CCREG), Index

registers (H:X) and related logic like arithmetic

unit, logic unit, multiplier and divider.

Bus Controller – Program Memory, Data

Memory & SFR’s (Special Function Register)

interface controls access into the program and

data memories and special registers. It con-

tains Program Counter (PC), Stack Pointer

(SP) register, and related logic.

Interrupt Controller - DF6808 extended IC

has implemented 9-level interrupt priority con-

trol. The interrupt requests may come from

external pin (IRQ) as well as from particular

peripherals. The DF6808 peripheral systems

generate maskable interrupts, which are rec-

ognized only if the global interrupt mask bit (I)

in the CCR is cleared. Maskable interrupts are

prioritized according to default arrangement

established during reset. When interrupt con-

dition occurs, an interrupt status flag is set to

indicate the condition.

I/O Ports - All ports are 8-bit general-purpose

bi-directional I/O system. The PORTA,

PORTB, PORTC, PORTD data registers have

their corresponding data direction registers

DDRA, DDRB, DDRC, DDRD to control ports

data flow. It assures that all DF6808’s ports

have full I/O selectable registers. Writes to

any ports pins cause data to be stored in the

data registers. If any port pins are configured

as output then data registers are driven out of

those pins. Reads from port pins configured

as input causes that input pin is read. If port

pins is configured as output, during read data

configured as outputs do not cause data to be

driven out of those pins, but the data is stored

in the output registers. Thus, if the pins later

become outputs, the last data written to port

will be driven out the port pins.

portao(7:0)

portdo(7:0)

portco(7:0)

portbo(7:0)

datai(7:0)

clk

rst

datao(7:0)

cap1

cap2

BUS

Controller

I/O

Ports

Opcode

Decoder

Interrupt

Controller

Timer

with

Compare /

Capture

Unit

SCI Unit

SPI Unit

irq

cmp1

cmp2

txd

rxd

scki

scko

sckz

ramoe

ramwe

addr(23:0)

halt

portai(7:0)

portdi(7:0)

portci(7:0)

portbi(7:0)

ddra(7:0)

ddrd(7:0)

ddrc(7:0)

ddrb(7:0)

Watchdog

Timer

ALU

prgdata(7:0)

prgaddr(15:0)

prgoe

ufroe

ufrwe

ufraddr(5:0)

ready

Control

Unit

DoCD

Debugger docdclk

docddatai

docddatao

prgwe

clkdocd

Timer & Compare - The programmable timer

is based on free-running 16-bit counter with a

fixed divide by four prescaler. plus input cap-

ture/output compare circuitry. The timer can

be used for many purposes including measur-

ing pulse length of two input signals and gen-

erating two output signals. The timer has 16-

bit architecture, hence each specific functional

segment is represented by two 8-bit registers.

These registers contains the high and low

byte of that functional block. Accessing the

low byte of a specific timer function allows full

control of that function, however, an access of

the high byte inhibits that specific timer func-

tion until the byte is also accessed.

Each of the input-capture channel has its own

16-bit time capture latch (input-capture regis-

ter) and each of the output-compare channel

has its own 16-bit compare register. Additional

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control bits permit software to control the

edge(s) that trigger each input-capture func-

tion and the automatic actions that result from

output-compare functions. Although hardwired

logic is included to automate many timer ac-

tivities, this timer architecture is essentially a

software-oriented system. This structure is

easily adaptable to a very wide range of appli-

cations although it is not as efficient as dedi-

cated hardware for some specific timing appli-

cations.

Watchdog Timer - The Watchdog Timer con-

sist of a free running Timer CLK/213 , plus con-

trol logic. The Watchdog Timer can be en-

abled by software by writing ‘1’ to the WDOG

bit in MISC register($000C). Once enabled

the WDT Timer cannot be disabled by soft-

ware. In addition the WDOG bit acts as a re-

set mechanism for the WDT timer. Writing

logic one ‘1’ to the WDOG bit clears Watch-

dog counter and inhibits Watchdog timeout

SCI - The SCI is a full-duplex UART type

asynchronous system, using standard non

return to zero (NRZ) format : 1 start bit, 8 or 9

data bits and a 1 stop bit. The DF6808 resyn-

chronizes the receiver bit clock on all one to

zero transitions in the bit stream. Therefore

differences in baud rate between the sending

device and the SCI are not as likely to cause

reception errors. Three logic samples are

taken near the middle of data bit time, and

majority logic decides the sense for the bit.

For the start and stop bits seven logic sam-

ples are taken. Even if noise causes one of

these samples to be incorrect, the bit will still

be received correctly. The receiver also has

the ability to enter a temporary standby mode

(called receiver wakeup) to ignore messages

intended for a different receiver. Logic auto-

matically wakes up the receiver in time to see

the first character of the next message. This

wakeup feature greatly reduces CPU over-

head in multi-drop SCI networks. The SCI

transmitter can produce queued characters of

idle (whole characters of all logic 1) and break

(whole characters of all logic 0). In addition to

the usual transmit data register empty (TDRE)

status flag, this SCI also provides a transmit

complete (TC) indication that can be used in

applications with a modem.

SPI Unit – it’s a fully configurable mas-

ter/slave Serial Peripheral Interface, which

allows user to configure polarity and phase of

serial clock signal SCK. It allows the micro-

controller to communicate with serial periph-

eral devices. It is also capable of interproces-

sor communications in a multi-master system.

A serial clock line (SCK) synchronizes shifting

and sampling of the information on the two

independent serial data lines. SPI data are

simultaneously transmitted and received. SPI

system is flexible enough to interface directly

with numerous standard product peripherals

from several manufacturers. Data rates as

high as CLK/4. Clock control logic allows a

selection of clock polarity and a choice of two

fundamentally different clocking protocols to

accommodate most available synchronous

serial peripheral devices. When the SPI is

configured as a master, software selects one

of four different bit rates for the serial clock.

SPI automatically drives slave select outputs

SSO[7:0], and address SPI slave device to

exchange serially shifted data. Error-detection

logic is included to support interprocessor

communications. A write-collision detector

indicates when an attempt is made to write

data to the serial shift register while a transfer

is in progress. A multiple-master mode-fault

detector automatically disables SPI output

drivers if more than one SPI devices simulta-

neously attempts to become bus master.

DoCDTM - Debug Unit – it’s a real-time hard-

ware debugger provides debugging capability

of a whole SoC system. In contrast to other

on-chip debuggers DoCD™ provides non-

intrusive debugging of running application. It

can halt, run, step into or skip an instruction,

read/write any contents of microcontroller in-

cluding all registers, internal, external, pro-

gram memories, all SFRs including user de-

fined peripherals. Hardware breakpoints can

be set and controlled on program memory,

internal and external data memories, as well

as on SFRs. Hardware breakpoint is executed

if any write/read occurred at particular address

with certain data pattern or without pattern.

The DoCDTM system includes three-wire inter-

face and complete set of tools to communi-

cate and work with core in real time debug-

ging. It is built as scalable unit and some fea-

tures can be turned off to save silicon and

reduce power consumption. A special care on

power consumption has been taken, and

when debugger is not used it is automatically

switched in power save mode. Finally whole

debugger is turned off when debug option is

no longer used.

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OPTIONAL

PERIPHERALS

There are also available an optional pe-

ripherals, not included in presented DF6808

Microcontroller Core. The optional peripherals,

can be implemented in microcontroller core

upon customer request.

I2C bus controller - Master

7-bit and 10-bit addressing modes

NORMAL, FAST, HIGH speeds

Multi-master systems supported

Clock arbitration and synchroni zation

User defined timings on I2C lines

Wide range of syst em clock frequ encies

Interrupt generation

I2C bus controller - Slave

NORMAL speed 100 kbs

FAST speed 400 kbs

HIGH speed 3400 kbs

Wide range of syst em clock frequ encies

User defined data setup time on I2C lines

Interrupt generation

PWM – Pulse Width Modulation Timer

Fixed-Point arithmetic coprocessor

Floating-Point arithmetic coprocessor

IEEE-754 standard single precision

PERFORMANCE

The following table gives a survey about

the Core area and performance in the

ALTERA® devices after Place & Route:

Device Speed

grade Logic Cells Fmax

CYCLONE -6 2635 61 MHz

CYCLONE II -6 2635 65 MHz

STRATIX -5 2636 65 MHz

STRATIX II -3 2124 96 MHz

STRATIX GX -5 2636 66 MHz

APEX20KC -7 2531 48 MHz

APEX20KE -1 2531 41 MHz

ACEX1K -1 2536 36 MHz

FLEX10KE -1 2536 36 MHz

Core performance in ALTERA® devices

Area utilized by the each unit of DF6808 core

in vendor specific technologies is summarized

in table below.

Component Area

[LC] [FFs]

CPU* 1 780 214

Main Timer 110 55

COM/CAP 150 60

Watchdog 29 14

SPI Interface 131 62

UART - SCI 272 124

I/O Ports 161 64

Total area 2 635 593

*CPU – consisted of ALU, Control Unit and Instruction Decoder, Bus

Controller with support for 64KB RAM, External IRQ pin Interrupt Con-

troller Core components area utili zation

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IMPROVEMENT

For user the most important is application

speed improvement. The most commonly

used arithmetic functions and theirs improve-

ment are shown in table below. Improvement

was computed as {M68HC08 clock periods}

divided by {DF6808 clock periods} required to

execute an identical function. More details are

available in core documentation

Function Improve-

ment

8-bit addition (immediate data) 4

8-bit addition (direct addressing) 4

8-bit addition (indirect addr essing) 3,6

8-bit subtraction (immediate data) 4

8-bit subtraction (direct addressing) 4

8-bit subtraction (indirect addressin g) 3,6

16-bit addition (immediate data) 4

16-bit addition (direct addressing) 4

16-bit addition (indirect addr essing 3,6

16-bit subtraction (immediate data ) 4

16-bit subtraction (direct addressin g) 4

16-bit subtraction (indirect addressing 3,6

Multiplication 5

Division 5

DF68XX FAMILY OVERVIEW

The main features of each DF68XX family member have been summarized in table below. It gives

a briefly member characterization helping user to select the most suitable IP Core for its application.

User can specify its own peripheral set (including listed below and the others) and requests the core

modifications.

Design

Physical Linear

memory space

Paged Data

Memory space

Motorola Memory

Expansion Logic

Interrupt sources

Interrupt levels

Real Time Inter-

rupt

Data Pointers

READY for Pro.

and Data mem.

Compare\Capture

Main Timer Sys-

tem

SCI (UART)

I\O Ports

SPI M/S Interface

Watchdog Timer

Pulse accumula-

tor

Interface for

additional SFRs

DoCD Debugger

Size – ASIC gates

DF6805 64k 64k - 7 7 - - * 2/2* 1* * 4 + * - 6 700

DF6808 64k 64k - 7 7 - - * 22* 1* * 4 * - 8 900

DF6811 64k 16M - 20 17 1* * 5/3* 1* * 4 * * * 12 000

DF6811CPU 64k 16M - 3 3 + 1* * + + + + + + + 6 500

DF68XX family of High Performance Mi crocontroller Cores

+ optional

* configurable

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CONTACTS

For any modification or special request

please contact to Digital Core Design or local

distributors.

Headquarters:

Wroclawska 94

41-902 Bytom, POLAND

e-mail: info@dcd.pl

tel. : +48 32 282 82 66

fax : +48 32 282 74 37

Distributors:

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