EM73461A
4-BIT MICRO-CONTROLLER FOR LCD PRODUCT
address
000h
002h
004h
006h
008h
00Ah
00Ch
00Eh
086h
4096 x 8 bits
Reset start address
INT0; External interrupt service routine entry address
HTCI; High speed timer interrupt service entry address
TRGA; Timer/counterA interrupt service routine entry address
TRGB; Timer/counter B interrupt service routine entry address
TBI; Time base interrupt service routine entry address
INT1; External interrupt service routine entry address
SCALL, subroutine call entry address
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FFFh
User's program and fixed data are stored in the program ROM. User's program is according the PC value
to send next executed instruction code. Fixed data can be read out by two ways.
(1) Table-look-up instruction :
Table -look-up instruction is depended on the Data Pointer (DP) to indicate to ROM address, then to get the
ROM code data.
LDAX
Acc ← ROM[DP]L
LDAXI
Acc ← ROM[DP]H,DP+1
DP is a 12-bit data register which can store the program ROM address to be the pointer for the ROM code
data. First, user load ROM address into DP by instruction "STADPL, STADPM, STADPH", then user can
get 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 777h by table-look-up instruction.
LDIA #07h;
STADPL
; DP3-0 ← 07h
STADPM ; DP5-4 ← 07h
STADPH
:
; DP8-6 ←07h, Load DP=777h
LDL#00h;
LDH#03h;
LDAX
STAMI
LDAXI
STAM
;
; ACC ← 6h
; RAM[30] ← 6h
; ACC ← 5h
; RAM[31] ← 5h
ORG777h
DATA 56h;
:
DATA RAM ( 244-nibble )
There is total 244 - nibble data RAM from address 00 to F3h
Data RAM includes 3 parts: zero page region, stacks and data area.
* This specification are subject to be changed without notice.
1.5.2001
4
ELAN [ ELAN MICROELECTRONICS CORP ]
