EM73866
4-BIT MICRO-CONTROLLER FOR LCD PRODUCT
Increment
Address
Bank 0
000h - 00Fh
Zero-page
010h - 01Fh
020h - 02Fh
:
:
:
0C0h - 0CFh
0D0h - 0DFh
Level 0
Level 4
Level 8
Level 12
Level 1
Level 5
Level 2
Level 6
Level 3
Level 7
0E0h - 0EFh
0F0h - 0F3h
Level 9 Level 10 Level 11
Bank 1
100h - 10Fh
110h - 11Fh
:
:
:
:
:
:
1F0h - 1FFh
ZERO- PAGE:
From 000h to 00Fh is the zero-page location. It is used as the zero-page address mode pointer for the
instruction of "STD #k,y; ADD #k,y; CLR y,b; CMP k,y".
PROGRAM EXAMPLE: To write immediate data "07h" to RAM [03] and to clear bit 2 of RAM [0Eh].
STD
CLR
#07h, 03h
0Eh,2
; RAM[03] ← 07h
; RAM[0Eh]2 ← 0
STACK:
There are 13 (maximum) stack levels that user can use for subroutine (including interrupt and CALL).
User can assign any level be the starting stack by providing the level number to stack pointer (SP).
When an instruction (CALL or interrupt) is invoked, before enter the subroutine, the previous PC address
is saved into the stack until returned from those subroutines, the PC value is restored by the data saved in stack.
SPECIAL PURPOSE REGISTER:
The instruction concerning with "Timer/counter", "Data Pointer" and "Stack Pointer" at instruction table 14
be sure the RAM bank must be set in Bank0.
DATA AREA:
Except the area used by user's application, the whole RAM can be used as data area for storing and loading
general data.
ADDRESSING MODE
The 500 nibble data memory consists of two banks (bank 0 and bank 1). There are 244x4 bits (address
000h~0F3h) in bank 0 and 256x4 bits (address 100h~1FFh) in bank 1.
* This specification are subject to be changed without notice.
12.29.1999
6
ELAN [ ELAN MICROELECTRONICS CORP ]
