12.3.3 Device Protection
Code Protect and Device secured state bits to determine the device security state and accessibility. The ROM firmware accessibility is defined based on the device state.
No Code Protect | Code Protect | |||||||
---|---|---|---|---|---|---|---|---|
Unsecured Device | Secured Device | Unsecured Device | Secured Device | |||||
Boot Key = 0 | Boot Key != 0 | Boot Key = 0 | Boot Key != 0 | Boot Key = 0 | Boot Key != 0 | Boot Key = 0 | Boot Key != 0 | |
Usage | Device with no security/code protect | Debug of secured device | Device with no security, lock program interfaces | Secured device | Device with no security | No intended usage | Device with no security, lock program interfaces | Secured device/code |
Firmware Authentication | No | Optional | No | Mandatory | No | Optional | No | Protected device |
Debug Support | Open | Open | Secure debug entry required | Secure debug entry required | Secure debug entry required | Secure debug entry required | Secure debug entry required | Secure debug entry required |
Serial Programming | All resources | All resources | None | Flash controller RoT | Chip erase only | Chip erase only | Chip erase only | Chip erase only |
DFU | Present | Present | Locked | Present | Present | Present | Locked | Present |
OTA | Present | Present | Present | Present | Present | Present | Present | Present |