Datasheet

© 2009 Microchip Technology Inc. Preliminary DS39937B-page 49
PIC24F04KA201 FAMILY
EXAMPLE 5-5: INITIATING A PROGRAMMING SEQUENCE – ASSEMBLY LANGUAGE CODE
EXAMPLE 5-6: INITIATING A PROGRAMMING SEQUENCE – ‘C’ LANGUAGE CODE
EXAMPLE 5-7: PROGRAMMING A SINGLE WORD OF FLASH PROGRAM MEMORY
DISI #5 ; Block all interrupts
for next 5 instructions
MOV #0x55, W0
MOV W0, NVMKEY ; Write the 55 key
MOV #0xAA, W1 ;
MOV W1, NVMKEY ; Write the AA key
BSET NVMCON, #WR ; Start the erase sequence
NOP ; 2 NOPs required after setting WR
NOP ;
BTSC NVMCON, #15 ; Wait for the sequence to be completed
BRA $-2 ;
// C example using MPLAB C30
asm("DISI #5"); // Block all interrupts for next 5 instructions
__builtin_write_NVM(); // Perform unlock sequence and set WR
; 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 #LOW_WORD_N, W2 ;
MOV #HIGH_BYTE_N, W3 ;
TBLWTL W2, [W0] ; Write PM low word into program latch
TBLWTH W3, [W0++] ; 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 #5 ; Disable interrupts while the KEY sequence is written
MOV #0x55, W0 ; Write the key sequence
MOV W0, NVMKEY
MOV #0xAA, W0
MOV W0, NVMKEY
BSET NVMCON, #WR ; Start the write cycle