Information

dsPIC33F/PIC24H PROGRAMMING SPECIFICATION

APPENDIX C: DIAGNOSTIC AND

CALIBRATION

REGISTERS

For dsPIC33FJ06GS101/102/202, dsPIC33FJ16GS402/

404/502/504, dsPIC33FJ32GS406/606/608/610 and

dsPIC33FJ64GS406/606/608/610 devices, the last six

instruction words of program memory store diagnostic

and calibration information. Any development tool that

modifies this memory must take care to preserve the data

contained in these registers.

Table C-1 provides an example of how the diagnostic

and calibration registers are read. This table can be

added to the programming executive between steps 1

and 2.

Table C-2 shows an example of how the diagnostic and

calibration registers are restored once the program

memory has been erased. This table can be added to

the programming executive between steps 4 and 5.

TABLE C-1: READ DIAGNOSTIC AND CALIBRATION REGISTERS

Command (Binary) Data (Hex) Description

Step 1: Initialize pointer to RAM.

0000 208006 MOV #0x800, W6

0000 000000 NOP

Step 2: Fill section of RAM.

0000 EB9B00 SETM [W6++]

0000 000000 NOP

Step 3: Repeat step two: 0x67 times.

Step 4: Initialize pointers to read diagnostic and Calibration Words for storage.

0000 200800 MOV #0x80, W0

0000 880190 MOV W0, TBLPAG

0000 207F47 MOV #0x7F4, W7

0000 208AE6 MOV #0x8AE, W6

0000 000000 NOP

Step 5: Read in diagnostic and Calibration Words.

0000 BA1B17 TBLRDL[W7], [W6++]

0000 000000 NOP

0000 BADB37 TBLRDH.B[W7++], [W6++]

0000 000000 NOP

0000 BADB57 TBLRDH.B[++W7], [W6++]

0000 000000 NOP

0000 BA1B37 TBLRDL[W7++], [W6++]

0000 000000 NOP

Step 6: Repeat step 5 three times to read all 6 instruction words.