PIC单片机的EEPROM读写实例及说明

PIC单片机的EEPROM读写实例及说明

; PIC 单片机的EEPROM 读写实例及说明;

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********; This is a program to test the function of readingwritting for EEPROM.; You can observe the value of register(30H--?) buy changing “VALU” and “WRC_”.; Notice that:it must be { ADDR+WRC_=0ffh } !;*******************************************************************

*********include “p16f877.inc”ADDR EQU 20H ;写入地址寄存器VALU EQU

21H ;写入值REC_ EQU 22H ;读计数WRC_ EQU 24H ;写计数org 0goto mainmainbcf STATUS,RP1bcf STATUS,RP0 ;bank0movlw 10hmovwf ADDR ;写入EEPROM 初始值movlw 90hmovwf VALU ;初始写入值movlw 30hmovwf FSR ;间址，读出值初始存放地址movlw 0Fhmovwf WRC_ ;写入次数movwf REC_;incf REC_ ;读出次数wri_ ;写子程序bsf STATUS,RP1bsf STATUS,RP0 ;bank3btfsc EECON1,WRgoto $-1bcf STATUS,RP0bcf STATUS,RP1 ;bank0movf ADDR,Wbsf STATUS,RP1 ;bank2movwf EEADRbcf STATUS,RP1 ;bank0movf VALU,Wbsf STATUS,RP1 ;bank2movwf EEDATAbsf STATUS,RP0 ;bank3bcf EECON1,EEPGD ;to data memorybsf EECON1,WRENbcf INTCON,GIEmovlw 55hmovwf EECON2movlw 0aahmovwf EECON2bsf EECON1,WRbcf STATUS,RP0bcf STATUS,RP1 ;bank0incf ADDR,1decf VALU,1decfsz WRC_ ;all write,to read_goto wri_read_ ;读子程序bcf STATUS,RP1bcf STATUS,RP0 ;bank0decf ADDR ;next valuebsf STATUS,RP1 ;bank2movwf EEADRbsf STATUS,RP0 ;bank3EEwr.asm 程序说明：1、本程序是对PIC16F877 单片机的EEPROM 数据区进行读写的演示程序；