31.3.2.2 Starting a Conversion

When the DAC is enabled (ENABLE=1 in DAC.CTRLA), a conversion starts as soon as the Data register (DAC.DATA) is written.

When the DAC is disabled (ENABLE=0 in DAC.CTRLA), writing DAC.DATA does not trigger a conversion. Instead, the conversion starts on writing a '1' to ENABLE in DAC.CTRLA.