PIC18F2420 MICROCHIP [Microchip Technology], PIC18F2420 Datasheet - Page 82

• Manufacturer Part Number: PIC18F2420
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F2420/2520/4420/4520
EXAMPLE 6-3:
DS39631A-page 80
READ_BLOCK
MODIFY_WORD
ERASE_BLOCK
Required
Sequence
WRITE_BUFFER_BACK
WRITE_BYTE_TO_HREGS
WRITING TO FLASH PROGRAM MEMORY
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
TBLRD*+
MOVF
MOVWF
DECFSZ
BRA
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BCF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
TBLRD*-
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVFF
MOVWF
TBLWT+*
DECFSZ
BRA
D'64
COUNTER
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
TABLAT, W
POSTINC0
COUNTER
READ_BLOCK
DATA_ADDR_HIGH
FSR0H
DATA_ADDR_LOW
FSR0L
NEW_DATA_LOW
POSTINC0
NEW_DATA_HIGH
INDF0
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
EECON1, FREE
INTCON, GIE
55h
EECON2
0AAh
EECON2
EECON1, WR
INTCON, GIE
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
D’64
COUNTER
POSTINC0, WREG
TABLAT
COUNTER
WRITE_WORD_TO_HREGS
Preliminary
; number of bytes in erase block
; point to buffer
; Load TBLPTR with the base
; address of the memory block
; read into TABLAT, and inc
; get data
; store data
; done?
; repeat
; point to buffer
; update buffer word
; load TBLPTR with the base
; address of the memory block
; point to Flash program memory
; access Flash program memory
; enable write to memory
; enable Row Erase operation
; disable interrupts
; write 55h
; write 0AAh
; start erase (CPU stall)
; re-enable interrupts
; dummy read decrement
; point to buffer
; number of bytes in holding register
; get low byte of buffer data
; present data to table latch
; write data, perform a short write
; to internal TBLWT holding register.
; loop until buffers are full
 2004 Microchip Technology Inc.