Datasheet

dsPIC30F1010/202X
DS70178C-page 84 Preliminary © 2006 Microchip Technology Inc.
7.6.3 LOADING WRITE LATCHES
Example 7-2 shows a sequence of instructions that
can be used to load the 96 bytes of write latches. 32
TBLWTL and 32 TBLWTH instructions are needed to
load the write latches selected by the table pointer.
EXAMPLE 7-2: LOADING WRITE LATCHES
7.6.4 INITIATING THE PROGRAMMING
SEQUENCE
For protection, the write initiate sequence for NVMKEY
must be used to allow any erase or program operation
to proceed. After the programming command has been
executed, the user must wait for the programming time
until programming is complete. The two instructions
following the start of the programming sequence
should be NOPs.
EXAMPLE 7-3: INITIATING A PROGRAMMING SEQUENCE
; Set up a pointer to the first program memory location to be written
; program memory selected, and writes enabled
MOV #0x0000,W0 ;
MOV W0
,
TBLPAG ; Initialize PM Page Boundary SFR
MOV #0x6000,W0 ; An example program memory address
; Perform the TBLWT instructions to write the latches
; 0th_program_word
MOV #LOW_WORD_0,W2 ;
MOV #HIGH_BYTE_0,W3 ;
TBLWTL W2
,
[W0] ; Write PM low word into program latch
TBLWTH W3
,
[W0++] ; Write PM high byte into program latch
; 1st_program_word
MOV #LOW_WORD_1,W2 ;
MOV #HIGH_BYTE_1,W3 ;
TBLWTL W2
,
[W0] ; Write PM low word into program latch
TBLWTH W3
,
[W0++] ; Write PM high byte into program latch
; 2nd_program_word
MOV #LOW_WORD_2,W2 ;
MOV #HIGH_BYTE_2,W3 ;
TBLWTL W2
,
[W0] ; Write PM low word into program latch
TBLWTH W3
,
[W0++] ; Write PM high byte into program latch
•
•
•
; 31st_program_word
MOV #LOW_WORD_31,W2 ;
MOV #HIGH_BYTE_31,W3 ;
TBLWTL W2
,
[W0] ; Write PM low word into program latch
TBLWTH W3
,
[W0++] ; Write PM high byte into program latch
Note: In Example 7-2, the contents of the upper byte of W3 have no effect.
DISI #5 ; Block all interrupts with priority <7
; for next 5 instructions
MOV #0x55,W0
MOV W0
,
NVMKEY ; Write the 0x55 key
MOV #0xAA,W1 ;
MOV W1
,
NVMKEY ; Write the 0xAA key
BSET NVMCON,#WR ; Start the erase sequence
NOP ; Insert two NOPs after the erase
NOP ; command is asserted