读写PIC18F452单片机內部EEPROM的实例

     list p=18f452
   #include <P18F452.INC>
;  
;---- 18F452 RAM LOCATIONS ------
Data_EE_Addr   EQU   0X000
Data_EE_Data   EQU   0X001
EEPROM_Buffer equ 0x02
;--------VECTORS------------

org 0x00  
        bra     START

;-------PROGRAM--------------
  
        org 0x20
START
        rcall   INIT
;
;----   Test the WRITE EEPROM Routine ----
;
clrf Data_EE_Addr ; set EEPROM start address at 0x00
movlw '0' ; Load a ASCII code "0" to W
movwf Data_EE_Data
EE_Write
rcall IN_DATA_EEW
incf Data_EE_Data,F ; 0x30+ N
incf Data_EE_Addr,F  ; Point to next EEPROM Address
btfss Data_EE_Addr,5 ; Write 32 bytes ?
goto EE_Write
;
;----   Test the READ EEPROM Routine ----
;
clrf FSR0H ; Set RAM point to 0x010
movlw 0x10
movwf FSR0L
;
clrf Data_EE_Addr
EE_Read
rcall READ_EEPROM
movwf POSTINC0 ; move W --> RAM then point + 1
;
incf Data_EE_Addr,F  ; Point to next EEPROM Address
btfss Data_EE_Addr,5 ; Read 32 bytes ?
goto EE_Read
;
LSTOP     
        GOTO   LSTOP        
;
;------ INTERNAL EEPROM READ ------
;
READ_EEPROM
movff Data_EE_Addr,EEADR
;
;       bcf     INTCON,GIE 
bcf EECON1,EEPGD
bsf EECON1,RD
movf EEDATA,W
;       bsf     INTCON,GIE 
return
;
;----INTERNAL EEPROM WRITE-----
;
IN_DATA_EEW
         movff  Data_EE_Addr,EEADR
         movff  Data_EE_Data,EEDATA
;
         BCF   EECON1,EEPGD
         BCF  EECON1,CFGS ; There are difference with data sheet
     
;         BCF     INTCON,GIE  
           
         BSF   EECON1,WREN
; 
         MOVLW   0X55
         MOVWF   EECON2
         MOVLW   0XAA
         MOVWF   EECON2     
         BSF  EECON1,WR
;        
;         BSF   INTCON,GIE

LOOP1    BTFSS   PIR2, EEIF
         GOTO    LOOP1
;
         BCF  EECON1,WREN  
         BCF   PIR2,EEIF
     
         RETURN

;---------INITIAL----------------
INIT     
         BCF      PIR2,EEIF
         BCF      PIE2,EEIE
         RETURN
;--------------------------------
            END