Write Synchronization for CTRLA.ENABLE

Setting the Enable bit in a module's Control A register (CTRLA.ENABLE) will trigger write-synchronization and set SYNCBUSY.ENABLE.

CTRLA.ENABLE will read its new value immediately after being written.

SYNCBUSY.ENABLE will be cleared by hardware when the operation is complete.

The Synchronization Ready interrupt (if available) cannot be used to enable write-synchronization.