Datasheet

 2003-2013 Microchip Technology Inc. DS30491D-page 91
PIC18F6585/8585/6680/8680
EXAMPLE 5-3: WRITING TO FLASH PROGRAM MEMORY (CONTINUED)
ERASE_BLOCK
MOVLW upper(CODE_ADDR) ; load TBLPTR with the base
MOVWF TBLPTRU ; address of the memory block
MOVLW high(CODE_ADDR)
MOVWF TBLPTRH
MOVLW low(CODE_ADDR)
MOVWF TBLPTRL
BSF EECON1, EEPGD ; point to Flash program memory
BCF EECON1, CFGS ; access Flash program memory
BSF EECON1, WREN ; enable write to memory
BSF EECON1, FREE ; enable Row Erase operation
BCF INTCON, GIE ; disable interrupts
MOVLW 55h
MOVWF EECON2 ; write 55H
Required MOVLW 0AAh
Sequence MOVWF EECON2 ; write AAH
BSF EECON1, WR ; start erase (CPU stall)
NOP
BSF INTCON, GIE ; re-enable interrupts
TBLRD*- ; dummy read decrement
WRITE_BUFFER_BACK
MOVLW 8 ; number of write buffer groups of 8 bytes
MOVWF COUNTER_HI
MOVLW high(BUFFER_ADDR) ; point to buffer
MOVWF FSR0H
MOVLW low(BUFFER_ADDR)
MOVWF FSR0L
PROGRAM_LOOP
MOVLW 8 ; number of bytes in holding register
MOVWF COUNTER
WRITE_WORD_TO_HREGS
MOVFW POSTINC0, W ; get low byte of buffer data
MOVWF TABLAT ; present data to table latch
TBLWT+* ; write data, perform a short write
; to internal TBLWT holding register.
DECFSZ COUNTER ; loop until buffers are full
BRA WRITE_WORD_TO_HREGS
PROGRAM_MEMORY
BSF EECON1, EEPGD ; point to Flash program memory
BCF EECON1, CFGS ; access Flash program memory
BSF EECON1, WREN ; enable write to memory
BCF INTCON, GIE ; disable interrupts
MOVLW 55h
MOVWF EECON2 ; write 55h
Required MOVLW 0AAh
Sequence MOVWF EECON2 ; write 0AAh
BSF EECON1, WR ; start program (CPU stall)
NOP
BSF INTCON, GIE ; re-enable interrupts
DECFSZ COUNTER_HI ; loop until done
BRA PROGRAM_LOOP
BCF EECON1, WREN ; disable write to memory
18F8680.book Page 91 Tuesday, January 29, 2013 1:32 PM