43.5.8 Register Access Protection
All registers with write-access are optionally write-protected by the Peripheral Access Controller (PAC), except the following registers:
- Control B (CTRLB43.8.2 Control B) register
- Interrupt Flag Status and Clear (INTFLAG43.8.7 Interrupt Flag Status and Clear) register
Write-protection is denoted by the PAC Write-Protection property in the register description.
Write-protection does not apply to accesses through an external debugger. Refer to the Peripheral Access Controller chapter for details.