10.7.1 Functional
The System Write command allows system data to be written to the device. Depending on the value of the P1 parameter, the host may write data to the configuration memory, program the fuses, send a checksum or set the user zone.
Command | CLA | INS | P1 | P2 | P3 | Data(N) |
|---|---|---|---|---|---|---|
Write Config Zone | $00 | $B4 | $00 | ADDR | N ≤ $10 | N bytes |
Write Fuses | $00 | $B4 | $01 | Fuse ID | $00 | |
Send Checksum | $00 | $B4 | $02 | $00 | $02 | 2 bytes |
Set User Zone | $00 | $B4 | $03 | Zone | $00 |
The anti-tearing function is controlled by P1: the host may choose to write in the Configuration zone with anti-tearing enabled by setting P1 = $08 instead of $00. Similarly, the host may choose to activate anti-tearing for a user zone by carrying out the Set User Zone command with P1 = $0B instead of $03. All subsequent Write User Zone commands are then carried out with anti-tearing enabled until the next Set User Zone command. Anti-tearing must be turned off if not required, as it would otherwise cause more write cycles than necessary.
Command Description | CLA | INS | P1 | P2 | P3 | Data(N) |
|---|---|---|---|---|---|---|
Write Config Zone w/a-t | $00 | $B4 | $08 | ADDR | N ≤ $08 | N bytes |
Set User Zone w/a-t | $00 | $B4 | $0B | Zone | $00 |