W925EP01 Datasheet, PDF (74/108 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925EP01/ W925EP01FG
Application Note: In-system Programming Software Examples
This application note illustrates the in-system programmability of the Winbond W925EP01 Flash
EPROM micro-controller. In this example, micro-controller will boot from 64 KB APROM bank and
waiting for a key to enter in-system programming mode for re-programming the contents of 64 KB
APROM. While entering in-system programming mode, micro-controller executes the loader program
in 4KB LDROM bank. The loader program erases the 64 KB APROM then reads the new code data
from external SRAM buffer (or through other interfaces) to update the 64KB APROM.
; EXAMPLE 1:
;**************************************************************************************************************
;* Example of 64K APROM program: Program will scan the P1.0. if P1.0 = 0, enters in-system
;* programming mode for updating the content of APROM code else executes the current ROM code.
;* XTAL = 4 MHz
;**************************************************************************************************************
.chip 8052
.RAMCHK OFF
.symbols
CHPCON
TA
SFRAL
SFRAH
SFRFD
SFRCN
EQU
EQU
EQU
EQU
EQU
EQU
EFH
EEH
E4H
E5H
E6H
E7H
ORG
0H
LJMP 100H
; JUMP TO MAIN PROGRAM
;************************************************************************
;* TIMER0 SERVICE VECTOR ORG = 000BH
;**********************************************************
**************
ORG 00BH
CLR TR0
; TR0 = 0, STOP TIMER0
MOV TL0,R6
MOV TH0,R7
RETI
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