33.6.6 Synchronization
Due to asynchronicity between the main clock domain and the peripheral clock domains, some registers need to be synchronized when written or read.
The following bits are synchronized when written:
- Software Reset bit in the CTRLA register (CTRLA.SWRST)
- Enable bit in the CTRLA register (CTRLA.ENABLE)
- Receiver Enable bit in the CTRLB register (CTRLB.RXEN)
Note: CTRLB.RXEN is write-synchronized somewhat
differently. See also CTRLB register for details.
Required write-synchronization is denoted by the "Write-Synchronized" property in the register description.