W78E58B_06 Datasheet, PDF (31/36 Pages) Winbond – 8-BIT MICROCONTROLLER

W78E58B/W78E058B
11. APPLICATION NOTES
11.1 In-system Programming Software Examples
This application note illustrates the in-system programmability of the Winbond W78E058B ROM
microcontroller. In this example, microcontroller will boot from 32KB APROM bank and waiting for a
key to enter in-system programming mode for re-programming the contents of 32KB APROM. While
entering in-system programming mode, microcontroller executes the loader program in 4KB LDROM
bank. The loader program erases the 32KB APROM then reads the new code data from external
SRAM buffer (or through other interfaces) to update the 32KB APROM.
EXAMPLE 1:
;*******************************************************************************************************************
;* Example of 32K 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 = 16 MHz
;*******************************************************************************************************************
.chip 8052
.RAMCHK OFF
.symbols
CHPCON
CHPENR
SFRAL
SFRAH
SFRFD
SFRCN
EQU
EQU
EQU
EQU
EQU
EQU
BFH
F6H
C4H
C5H
C6H
C7H
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
;************************************************************************
;* 32K APROM MAIN PROGRAM
;************************************************************************
ORG 100H
MAIN_32K:
MOV A, P1
; SCAN P1.0
ANL A, #01H
CJNE A, #01H, PROGRAM_32K; IF P1.0 = 0, ENTER IN-SYSTEM PROGRAMMING MODE
JMP NORMAL_MODE
PROGRAM_32K:
MOV CHPENR, #87H
MOV CHPENR, #59H
MOV CHPCON, #03H
; CHPENR = 87H, CHPCON REGISTER WRTE ENABLE
; CHPENR = 59H, CHPCON REGISTER WRITE ENABLE
; CHPCON = 03H, ENTER IN-SYSTEM PROGRAMMING MODE
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Publication Release Date: December 4, 2006
Revision A8