2.2.1 ADC.STATUS.BUSY Can Not be Trusted During Initialization

When the ADC peripheral is enabled with CTRLA.ONDEMAND = '0', the initialization time starts as expected, but the STATUS.BUSY bit cannot be trusted. When a trigger is given to start an ADC conversion, the STATUS.BUSY bit goes high as expected.

Work Around

Either wait for a sufficiently long time for the ADC peripheral to complete the initialization phase, or perform a dummy conversion to ensure that the initialization time has completed and the ADC is ready.

Affected Silicon Revisions

Rev. A1
X