T32UC3L0128_14 Datasheet, PDF (88/852 Pages) ATMEL Corporation – Compact Single-cycle RISC Instruction Set Including DSP Instructions

AT32UC3L0128/256
8.7 Security Bit
The security bit allows the entire device to be locked from external JTAG, aWire, or other debug
access for code security. The security bit can be written by a dedicated command, Set Security
Bit (SSB). Once set, the only way to clear the security bit is through the JTAG or aWire Chip
Erase command.
Once the security bit is set, the following Flash Controller commands will be unavailable and
return a lock error if attempted:
• Write General-Purpose Fuse Bit (WGPB) to BOOTPROT or EPFL fuses
• Erase General-Purpose Fuse Bit (EGPB) to BOOTPROT or EPFL fuses
• Program General-Purpose Fuse Byte (PGPFB) of fuse byte 2
• Erase All General-Purpose Fuses (EAGPF)
One error can be detected in the FSR register after issuing the command:
• Programming Error: A bad keyword and/or an invalid command have been written in the
FCMD register.
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