55.4.10.2 Register Write Protection
To prevent any single software error from corrupting SHA behavior, certain registers in the address space can be write-protected by setting the WPEN (Write Protection Enable), WPITEN (Write Protection Interrupt Enable), and/or WPCREN (Write Protection Control Enable) bits in the SHA Write Protection Mode register (SHA_WPMR).
If a write access to a write-protected register is detected, the Write Protection Violation Status (WPVS) flag in the SHA Write Protection Status register (SHA_WPSR) is set and the Write Protection Violation Source (WPVSRC) field indicates the register in which the write access has been attempted.
The WPVS bit is automatically cleared after reading SHA_WPSR.
The following register(s) can be write-protected when SHA_WPMR.WPEN is set:
The following register(s) can be write-protected when WPITEN is set:
The following register(s) can be write-protected when WPCREN is set: