Datasheet

 2006-2012 Microchip Technology Inc. DS41291G-page 123
PIC16F882/883/884/886/887
An example of the complete eight-word write sequence
is shown in Example 10-4. The initial address is loaded
into the EEADRH and EEADR register pair; the eight
words of data are loaded using indirect addressing.
EXAMPLE 10-4: WRITING TO FLASH PROGRAM MEMORY
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; This write routine assumes the following:
; A valid starting address (the least significant bits = '000')
; is loaded in ADDRH:ADDRL
; ADDRH, ADDRL and DATADDR are all located in data memory
;
BANKSEL EEADRH
MOVF ADDRH,W ; Load initial address
MOVWF EEADRH ;
MOVF ADDRL,W ;
MOVWF EEADR ;
MOVF DATAADDR,W ; Load initial data address
MOVWF FSR ;
LOOP MOVF INDF,W ; Load first data byte into lower
MOVWF EEDATA ;
INCF FSR,F ; Next byte
MOVF INDF,W ; Load second data byte into upper
MOVWF EEDATH ;
INCF FSR,F ;
BANKSEL EECON1
BSF EECON1,EEPGD ; Point to program memory
BSF EECON1,WREN ; Enable writes
BCF INTCON,GIE ; Disable interrupts (if using)
BTFSC INTCON,GIE ; See AN576
GOTO $-2
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; Required Sequence
MOVLW 55h ; Start of required write sequence:
MOVWF EECON2 ; Write 55h
MOVLW 0AAh ;
MOVWF EECON2 ; Write 0AAh
BSF EECON1,WR ; Set WR bit to begin write
NOP ; Required to transfer data to the buffer
NOP ; registers
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BCF EECON1,WREN ; Disable writes
BSF INTCON,GIE ; Enable interrupts (comment out if not using interrupts)
BANKSEL EEADR
MOVF EEADR, W
INCF EEADR,F ; Increment address
ANDLW 0x0F ; Indicates when sixteen words have been programmed
SUBLW 0x0F ; 0x0F = 16 words
; 0x0B = 12 words (PIC16F884/883/882 only)
; 0x07 = 8 words
; 0x03 = 4 words(PIC16F884/883/882 only)
BTFSS STATUS,Z ; Exit on a match,
GOTO LOOP ; Continue if more data needs to be written