PIC24FJ256GB110-I Datasheet, PDF (62/328 Pages) Microchip Technology – 64/80/100-Pin, 16-Bit Flash Microcontrollers with USB On-The-Go (OTG)

PIC24FJ256GB110 FAMILY
4.6.2
PROGRAMMING A SINGLE WORD
OF FLASH PROGRAM MEMORY
If a Flash location has been erased, it can be pro-
grammed using table write instructions to write an
instruction word (24-bit) into the write latch. The
TBLPAG register is loaded with the 8 Most Significant
Bytes of the Flash address. The TBLWTL and TBLWTH
instructions write the desired data into the write latches
and specify the lower 16 bits of the program memory
address to write to. To configure the NVMCON register
for a word write, set the NVMOP bits (NVMCON<3:0>)
to ‘0011’. The write is performed by executing the
unlock sequence and setting the WR bit (see
Example 4-4).
EXAMPLE 4-4: PROGRAMMING A SINGLE WORD OF FLASH PROGRAM MEMORY
; Setup a pointer to data Program Memory
MOV
#tblpage(PROG_ADDR), W0
;
MOV
W0, TBLPAG
;Initialize PM Page Boundary SFR
MOV
#tbloffset(PROG_ADDR), W0
;Initialize a register with program memory address
MOV
MOV
TBLWTL
TBLWTH
#LOW_WORD_N, W2
#HIGH_BYTE_N, W3
W2, [W0]
W3, [W0++]
;
;
; Write PM low word into program latch
; Write PM high byte into program latch
; Setup NVMCON for programming one word to data Program Memory
MOV
#0x4003, W0
;
MOV
W0, NVMCON
; Set NVMOP bits to 0011
DISI
MOV
MOV
MOV
MOV
BSET
#5
#0x55, W0
W0, NVMKEY
#0xAA, W0
W0, NVMKEY
NVMCON, #WR
; Disable interrupts while the KEY sequence is written
; Write the key sequence
; Start the write cycle
DS39897B-page 60
Preliminary
© 2008 Microchip Technology Inc.