Writing this bit to '1' write-protects the WDT.CTRLA register.

It is only possible to write this bit to '1'. This bit can be cleared in Debug mode only.

If the PERIOD bits in WDT.CTRLA are different from zero after boot code, the lock will automatically be set.

This bit is under CCP.

This bit is set after writing to the WDT.CTRLA register while the data is being synchronized from the system clock domain to the WDT clock domain.

This bit is cleared by the system after the synchronization is finished.

This bit is not under CCP.