EM73MA89B
4-BIT MICRO-CONTROLLER FOR LCD PRODUCT
B
XA2
:
;--------------- -------------------- -------------------- -------------------- --
BANK 2
XB1 :
:
:
B
XB
:
XB2 :
:
B
XB2
:
;--------------- -------------------- -------------------- -------------------- --
BANK 3
XC1 :
:
:
B
XC
:
XC2 :
:
B
XC2
ry
limina
Pre
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
LDAXI
Acc
←
ROM[DP]
L
Acc
←
ROM[DP]
H
,DP+1
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
STADPL
STADPM
STADPH
:
LDL
LDH
LDAX
STAMI
LDAXI
STAM
;
ORG
DATA
#07h;
; [DP]
L
←
07h
; [DP]
M
←
07h
; [DP]
H
←
07h, Load DP=777h
#00h;
#03h;
; ACC
←
6h
; RAM[30]
←
6h
; ACC
←
5h
; RAM[31]
←
5h
1777h
56h;
DATA RAM ( 1012-nibble )
A total 1012 - nibble data RAM is available from address 000 to 3FFh
Data RAM includes the zero page region, stacks and data areas.
* This specification are subject to be changed without notice.
10.15.2002 (V1.3)
7
EMC [ ELAN MICROELECTRONICS CORP ]
