13.3.3 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.

Table 13-4. Device Protection
No Code Protect Code Protect
Unsecured DeviceSecured DeviceUnsecured DeviceSecured Device
Boot Key = 0 Boot Key != 0Boot Key = 0 Boot Key != 0Boot Key = 0 Boot Key != 0Boot Key = 0 Boot Key != 0
UsageDevice with no security/code protectDebug of secured deviceDevice with no security, lock program interfacesSecured deviceDevice with no securityNo intended usageDevice with no security, lock program interfacesSecured device/code
Firmware Authentication NoOptionalNoMandatoryNoOptionalNoMandatory
Debug SupportOpenOpenSecure debug entry requiredSecure debug entry requiredSecure debug entry requiredSecure debug entry requiredSecure debug entry requiredSecure debug entry required
Serial ProgrammingAll resourcesAll resourcesNoneFlash controller RoTChip erase onlyChip erase onlyChip erase onlyChip erase only
DFUPresentPresentLockedPresentPresentPresentLockedPresent
OTAPresentPresentPresentPresentPresentPresentPresentPresent