To prevent any single software error from corrupting TWIHS behavior, certain registers in the address space can be write-protected by setting the WPEN bit in the TWIHS Write Protection Mode Register (TWIHS_WPMR).
If a write access to a write-protected register is detected, the WPVS bit in the TWIHS Write Protection Status Register (TWIHS_WPSR) is set and the field WPVSRC indicates the register in which the write access has been attempted.
The WPVS bit is automatically cleared after reading TWIHS_WPSR.
The following registers can be write-protected: