EM73P968
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
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+1
H
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
:
#07h;
; [DP] ← 07h
L
; [DP] ← 07h
M
; [DP] ← 07h, Load DP=777h
H
LDL
LDH
#00h;
#03h;
LDAX
STAMI
LDAXI
STAM
;
; ACC ← 6h
; RAM[30] ← 6h
; ACC ← 5h
; RAM[31] ← 5h
ORG
DATA
1777h
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.
* This specification are subject to be changed without notice.
8.14.2001
8
ELAN [ ELAN MICROELECTRONICS CORP ]
