10.7.3 Write Fuses
|
Fuse |
Fuse ID |
|---|---|
|
SEC |
$07 |
|
FAB |
$06 |
|
CMA |
$04 |
|
PER |
$00 |
The fuses may only be programmed, that is, written from one to zero. The write fuses operation is allowed only after successfully presenting the secure code (Write 7 password). The fuses must be blown sequentially:
- FAB must be blown first.
- CMA may be blown only if FAB is zero.
- PER may be blown only if CMA is zero.
The SEC fuse is blown at the Microchip factory to protect lot history information.