19.6.6 Synchronization

Due to asynchronicity between the main clock domain and the peripheral clock domains, some registers need to be synchronized when written or read.

An exception is the Channel Enable bit in the Peripheral Channel Control registers (PCHCTRLm.CHEN). When changing this bit, the bit value must be read-back to ensure the synchronization is complete and to assert glitch free internal operation. Note that changing the bit value under ongoing synchronization will not generate an error.

The following registers are synchronized when written:
  • Generic Clock Generator Control register (GENCTRLn)
  • Control A register (CTRLA)

Required write synchronization is denoted by the “Write Synchronized” property in the register description.