PIC18FXXK80 Datasheet, PDF (28/52 Pages) Microchip Technology – Flash Microcontroller Programming Specification

PIC18FXXK80 FAMILY
3.4 ID Location Programming
The ID locations are programmed much like the code
memory. The ID registers are mapped in addresses,
200000h through 200007h. These locations read out
normally even after code protection.
Note:
The user only needs to fill the first 8 bytes
of the write buffer in order to write the ID
locations.
Table 3-14 demonstrates the code sequence required
to write the ID locations.
In order to modify the ID locations, refer to the method-
ology described in Section 3.2.2 “Modifying Code
Memory”. As with code memory, the ID locations must
be erased before being modified.
TABLE 3-14: WRITE ID SEQUENCE
4-Bit
Command
Data Payload
Core Instruction
Step 1: Direct access to code memory and enable writes.
0000
0000
8E 7F
9C 7F
BSF EECON1, EEPGD
BCF EECON1, CFGS
Step 2: Load write buffer with 8 bytes and write.
0000
0000
0000
0000
0000
0000
1101
1101
1101
1111
0000
0E 20
6E F8
0E 00
6E F7
0E 00
6E F6
<MSB><LSB>
<MSB><LSB>
<MSB><LSB>
<MSB><LSB>
00 00
MOVLW 20h
MOVWF TBLPTRU
MOVLW 00h
MOVWF TBLPTRH
MOVLW 00h
MOVWF TBLPTRL
Write 2 bytes and post-increment address by 2.
Write 2 bytes and post-increment address by 2.
Write 2 bytes and post-increment address by 2.
Write 2 bytes and start programming.
NOP - hold PGC high for time P9 and low for time P10.
DS39972B-page 28
 2011 Microchip Technology Inc.