11.3.6 Software Reset Write-Synchronization

Writing a one to the Software Reset bit in CTRL (CTRLA.SWRST) will also trigger write-synchronization and set SYNCBUSY.SWRST. When writing a one to the CTRLA.SWRST bit it will immediately read as one. CTRLA.SWRST and SYNCBUSY.SWRST will be cleared by hardware when the peripheral has been reset. Writing a zero to the CTRLA.SWRST bit has no effect. The Synchronization Ready interrupt (if available) cannot be used for Software Reset write-synchronization.