dsPIC33F/PIC24H PROGRAMMING SPECIFICATION
Reading the contents of executive memory can be
performed using the same technique described in
6.2
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.
Section 5.8 “Reading Code Memory”. A procedure
for reading executive memory is shown in Table 6-2.
Note that in Step 2, the TBLPAG register is set to 0x80,
such that executive memory may be read.
TABLE 6-2:
READING EXECUTIVE MEMORY
Command
(Binary)
Data
(Hex)
Description
Step 1: Exit the Reset vector.
0000
0000
0000
0000
000000
000000
040200
000000
NOP
NOP
GOTO
NOP
0x200
Step 2: Initialize TBLPAG and the read pointer (W6) for TBLRDinstruction.
0000
0000
0000
200800
880190
EB0300
MOV
MOV
CLR
#0x80, W0
W0, TBLPAG
W6
Step 3: Initialize the write pointer (W7) to point to the VISI register.
0000 207847 MOV #VISI, W7
Step 4: Read and clock out the contents of the next two locations of executive memory through the VISI register
using the REGOUTcommand.
0000
0000
0000
0000
0001
0000
0000
0000
0001
000000
BA1B96
000000
000000
<VISI>
BA9BB6
000000
000000
<VISI>
NOP
TBLRDL [W6], [W7]
NOP
NOP
Clock out contents of VISI register
TBLRDH [W6++], [W7]
NOP
NOP
Clock out contents of VISI register
Step 5: Reset the device internal PC.
0000
0000
040200
000000
GOTO
NOP
0x200
Step 6: Repeat Steps 4-5 until all 2048 instruction words of executive memory are read.
© 2007 Microchip Technology Inc.
Preliminary
DS70152D-page 71
MICROCHIP [ MICROCHIP ]
