8

* This specification are subject to be changed without notice.

8.14.2001

EM73P968

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

Preliminar

y

B

XA2

:

; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

BANK 2

XB1 :

:

:

BXB

:

XB2 :

:

B

XB2

:

; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

BANK 3

XC1 :

:

:

BXC

:

XC2 :

:

B

XC2

Fixed data can be read out by table-look-up instruction. Table-look-up instruction is requires the Data point

(DP) to indicate the ROM address in obtaining the ROM code data (Except bank 0) :

LDAX

Acc ←

←

←

←

← ROM[DP]

L

LDAXI

Acc ←

←

←

←

← ROM[DP]

DP is a 12-bit data register that stores the program ROM address as pointer for the ROM code data.

User has to initially load ROM address into DP with instructions "STADPL", and "STADPM, STADPH",

then to obtain the lower nibble of ROM code data by instruction "LDAX" and higher nibble by instruction

"LDAXI".

PROGRAM EXAMPLE: Read out the ROM code of address 1777h by table-look-up instruction.

LDIA

#07h;

STADPL

; [DP]

STADPM

; [DP]

STADPH

; [DP]

:

LDL

#00h;

LDH

#03h;

LDAX

; ACC ← 6h

STAMI

; RAM[30] ← 6h

LDAXI

; ACC ← 5h

STAM

; RAM[31] ← 5h

;

ORG

1777h

DATA

56h;

DATA RAM ( 2548-nibble )

A total 2548 - nibble data RAM is available from address 000 to 9FFh

Data RAM includes the zero page region, stacks and data areas.