6

* This specification are subject to be changed without notice.

7.20.1999

EM73201

4-BIT MICRO-CONTROLLER FOR GENERAL PURPOSE PRODUCT

Preliminary

STA x ; RAM[x] ← Acc

(3) Zero-page addressing mode

For zero-page region, user can using direct addressing to write or do any arithematic, comparsion

or bit manupulated operation directly.

ADD #k,y; RAM[y] ← RAM[y] + #k

PROGRAM COUNTER (2K ROM)

Program counter ( PC ) is composed by a 12-bit counter, which indicates the next executed address for the

instruction of program ROM.

For a 2 K - byte size ROM, PC can indicate address form 000h - 7FFh, for BRANCH and CALL instrcutions,

PC is changed by instruction indicating.

(1) Branch instruction:

SBR a

Object code: 00aa aaaa

Condition: SF=1; PC ← PC

a

SF=0; PC← PC +1( branch condition not satisified)

PC

Original PC value + 1

LBR a

Object code: 1100 aaaa aaaa aaaa

Condition: SF=1; PC ← a ( branch condition satisified)

PC

0 a a a a a a a a a a a

SF=0 ; PC ← PC + 2 ( branch condition not satisified )

PC

Original PC value + 2

(2) Subroutine instruction:

SCALL a

Object code: 1110 nnnn

Condition : PC ← a ; a=8n+6 ; n=1..15 ; a=86h, n=0

PC 0 0 0 0 a a a a a a a

a

LCALL a

Object code: 0100 0 aaa aaaa aaaa

Condition: PC ← a