EM73P461A
4-BIT MICRO-CONTROLLER FOR LCD PRODUCT
PROGRAM ROM (8K X 8 bits)
8 K x 8 bits program ROM contains user's program and some fixed data .
The basic structure of program ROM can be divided into 6 parts.
1. Address 0000h: Reset start address.
2. Address 0002h - 000Ch : 6 kinds of interrupt service routine entry addresses .
3. Address 000Eh - 0086h : SCALL subroutine entry address, only available at 000Eh, 0016h, 001Eh, 0026h, 002Eh,
0036h, 003Eh, 0046h, 004Eh, 0056h, 005Eh, 0066h, 006Eh, 0076h, 007Eh, 0086h.
4. Address 0000h - 07FFh : LCALL subroutine entry address.
5. Address 0000h - 1FFFh : Except used as above function, the other region can be used as user's program region.
6. Address 1000h - 1FFFh : Fixed data stortage area.
address
000h
002h
004h
006h
008h
00Ah
00Ch
00Eh
086h
800h
:
8192 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
LCALL entry address
SCALL, subroutine call entry address
1000h
:
FFFh
1FFFh
Bank 1
fixed data area
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 table-look-up instruction.
Please note that fixed data only can be stored in 8K ROM Bank 1.
The program counter is a 13-bit binary counter. The PC can defined 8K ROM.
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 13-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".
* This specification are subject to be changed without notice.
12.27.2001
6
ELAN [ ELAN MICROELECTRONICS CORP ]
