EM78871

8-bit Micro-controller

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* This specification is subject to be changed without notice.

8/23/04 (V1.5)

11

VII.Functional Descriptions

VII.1 Operational Registers

Fig.4 control register configuration

VII.2 Operational Register Detail Description

R0 (Indirect Addressing Register)

R0 is not a physically implemented register. It is useful as indirect addressing pointer. Any instruction using R0 as

register actually accesses data pointed by the RAM Select Register (R4).

Example:

Mov

a,@0x20

;store a address at R4 for indirect addressing

Mov

0x04,A

Mov

a,@0xAA ;write data 0xAA to R20 at bank0 through R0

Mov

0x00,A

00

01

02

03

04

05

06

07

08

09

0A

0B

0C

0D

0E

0F

10

:

1F

20

:

3F

R0

R1(TCC buffer)

R2(PC)

R3(STATUS)

R4(RSR, BANK SELECT

R5(PORT57..PORT55

Program ROM PAGE)

R6(PORT6)

R7(PORT7)

R8(PORT8)

R9(PORT9)

RA(CPU MODE,CLOCK,

FSK,WDT control)

RB(PORTB)

RC(PORTC)

RD(Comparator control)

RE(Key scan , LCD control)

RF(Interrupt flag)

16 byte COMMON

REGISTER

BANK0 , BANK1, BANK2 ,BANK3

32X8

32X8

32X8

32X8

COMMOM REGISTER

R4(SPI status and control

R5(SPI data buffer)

R6 (Unused)

R7(Unused)

R8(Unused)

R9(EDD,LCDA8)

RC(DATA RAM data buffer)

RD(DATA RAM address

address 7 .. address 0)

RE(,DATA RAM address

address 11 .. address 8)

ADDRESS

REGISTER

(PAGE0)

REGISTER

(PAGE1)

CONTROL REGISTER

(PAGE0)

IOC5(IOC55,56,57,P8S,

P9S,PBS,PCS)

IOC6(PORT6 IO control)

IOC7 (PORT7 IO control)

IOC8 (PORT8 IO control)

IOC9 (PORT9 IO control

IOCA(COUNTER1,2,

prescaler and source)

IOCB(PORTB IO control)

IOCC(PORTC IO control)

IOCD(COUNTER1 PRESET)

IOCE(COUNTER2 PRESET)

IOCF(Interrupt control)

R3(7)

IOC5(Key tone, LCD bias control)

IOC6 (current DA)

IOC7(key strobe , seg7 .. seg0)

IOC8(key strobe, seg15.. seg8)

IOC9(DTMF receiver control)

IOCA(PORT7 pull high)

IOCB(PORT6 pull high)

IOCC(Tone1)

IOCD(Tone2)

IOCE

CONTROL REGISTER

(PAGE1)

R3(5,6)

RA(LCD RAM address)

RB (LCD RAM data buffer)

R4(7,6)

LCD RAM

RA PAGE1 => address

RB PAGE1 =>data

DATA RAM

RD PAGE1 => address7..0

RC PAGE1 =>data

RE PAGE1 => address11..8

IOC6 (Port s/w, LCDDV, CDAL)

R3(5,6)

CONTROL REGISTER

(PAGE2)

IOCE

IOC5 ( Stack Pointer )