PIC24FJ64GA004-IPT Datasheet, PDF (45/52 Pages) Microchip Technology – PIC24FJXXXGA0XX Flash Programming Specification

PIC24FJXXXGA0XX
5.4.2 PROGRAMMING VERIFICATION
After the programming executive has been
programmed to executive memory using ICSP, it must
be verified. Verification is performed by reading out the
contents of executive memory and comparing it with
the image of the programming executive stored in the
programmer.
Reading the contents of executive memory can be
performed using the same technique described in
Section 3.8 “Reading Code Memory”. A procedure
for reading executive memory is shown in Table 5-6.
Note that in Step 2, the TBLPAG register is set to 80h,
such that executive memory may be read. The last
eight words of executive memory should be verified
with stored values of the Diagnostic and Calibration
Words to ensure accuracy.
TABLE 5-6: READING EXECUTIVE MEMORY
Command
(Binary)
Data
(Hex)
Description
Step 1: Exit the Reset vector.
0000
0000
0000
000000
040200
000000
NOP
GOTO
NOP
0x200
Step 2: Initialize TBLPAG and the Read Pointer (W6) for TBLRD instruction.
0000
0000
0000
200800 MOV
880190 MOV
EB0300 CLR
#0x80, W0
W0, TBLPAG
W6
Step 3: Initialize the Write Pointer (W7) to point to the VISI register.
0000
0000
207847 MOV
000000 NOP
#VISI, W7
Step 4: Read and clock out the contents of the next two locations of executive memory through the VISI register
using the REGOUT command.
0000
0000
0000
0001
0000
0000
0000
0000
0000
0000
0000
0001
0000
0000
0000
0000
0001
0000
BA0B96
000000
000000
<VISI>
000000
BADBB6
000000
000000
BAD3D6
000000
000000
<VISI>
000000
BA0BB6
000000
000000
<VISI>
000000
TBLRDL [W6], [W7]
NOP
NOP
Clock out contents of VISI register
NOP
TBLRDH.B [W6++], [W7++]
NOP
NOP
TBLRDH.B [++W6], [W7--]
NOP
NOP
Clock out contents of VISI register
NOP
TBLRDL [W6++], [W7]
NOP
NOP
Clock out contents of VISI register
NOP
Step 5: Reset the device internal PC.
0000
0000
040200 GOTO
000000 NOP
0x200
Step 6: Repeat Steps 4 and 5 until all desired code memory is read.
© 2008 Microchip Technology Inc.
DS39768D-page 45