W79E217A Datasheet, PDF (204/207 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E217A Data Sheet
MOV TCON, #00H
; TCON = 00H, TR = 0 TIM0 STOP
MOV IP, #00H
; IP = 00H
MOV IE, #82H
; IE = 82H, TIMER0 INTERRUPT ENABLED
MOV TMOD, #01H
; TMOD = 01H, MODE1
MOV R6,#D0H
; SET WAKE-UP TIME FOR ERASE OPERATION, ABOUT
15 ms DEPENDING ON USER'S SYSTEM CLOCK RATE.
MOV R7, #8AH
MOV TL0, R6
MOV TH0, R7
ERASE_P_4K:
MOV SFRCN, #22H
MOV TCON, #10H
MOV PCON, #01H
; SFRCN = 22H, ERASE APFlash APFlash0
; SFRCN = A2H, ERASE APFlash1
; TCON = 10H, TR0 = 1, GO
; ENTER IDLE MODE (FOR ERASE OPERATION)
;*********************************************************************
;* BLANK CHECK
;*********************************************************************
MOV SFRCN, #0H
; SFRCN = 00H, READ APFlashB APFlash0
; SFRCN = 80H, READ APFlashB APFlash1
MOV SFRAH, #0H
; START ADDRESS = 0H
MOV SFRAL, #0H
MOV R6, #FDH
; SET TIMER FOR READ OPERATION, ABOUT 1.5 μS.
MOV R7, #FFH
MOV TL0, R6
MOV TH0, R7
blank_check_loop:
SETB TR0
MOV PCON, #01H
MOV A, SFRFD
CJNE A, #FFH, blank_check_error
INC SFRAL
MOV A, SFRAL
JNZ blank_check_loop
INC SFRAH
MOV A, SFRAH
CJNE A, #0H, blank_check_loop
JMP PROGRAM_APFlashROM
; Enable TIMER 0
; Enter idle mode
; Read one byte
; Next address
; End address = FFFFH
blank_check_error:
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Publication Release Date: December 14, 2007
Revision A3.0