13.3 Register Synchronization
There are two different register synchronization schemes implemented on this device: common synchronizer register synchronization and distributed synchronizer register synchronization.
The modules using a common synchronizer register synchronization are: GCLK, WDT, RTC, EIC, TC, ADC, AC and DAC.
The modules adopting a distributed synchronizer register synchronization are: SERCOM USART, SERCOM SPI, SERCOM I2C.