W79E632A Datasheet, PDF (74/79 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E632A/W79L632A
20. APPLICATION NOTE
In-system Programming Software Examples
This application note illustrates the in-system programmability of the Nuvoton W79E(L)632 Flash
EPROM microcontroller. In this example, microcontroller will boot from 64 KB APFlash bank and waiting
for a key to enter in-system programming mode for re-programming the contents of 64 KB APFlash.
While entering in-system programming mode, microcontroller executes the loader program in 4KB
LDFlash bank. The loader program erases the 64 KB APFlash then reads the new code data from
external SRAM buffer (or through other interfaces) to update the 64KB APFlash.
If the customer uses the reboot mode to update his program, please enable this b3 or b4 of security bits
from the writer. Please refer security bits for detail descrption
EXAMPLE 1:
;*******************************************************************************************************************
;* Example of 64K APFlash program: Program will scan the P1.0. if P1.0 = 0, enters in-system
;* programming mode for updating the content of APFlash code else executes the current ROM code.
;* XTAL = 24 MHz
;*******************************************************************************************************************
.chip 8052
.RAMCHK OFF
.symbols
CHPCON
TA
SFRAL
SFRAH
SFRFD
SFRCN
EQU
EQU
EQU
EQU
EQU
EQU
9FH
C7H
ACH
ADH
AEH
AFH
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
;************************************************************************
;* 64K APFlash MAIN PROGRAM
;************************************************************************
ORG 100H
MAIN_64K:
MOV A,P1
ANL A,#01H
CJNE A,#01H,PROGRAM_64K
JMP NORMAL_MODE
; SCAN P1.0
; IF P1.0 = 0, ENTER IN-SYSTEM PROGRAMMING MODE
- 74 -