27.2.3 ADC Operation During Sleep

The ADC module can operate in Sleep. This requires the ADC clock source to be set to the ADCRC option. When the ADC oscillator source is selected, the ADC waits one additional instruction before starting the conversion. This allows the SLEEP instruction to be executed, which can reduce system noise during the conversion. If the ADC interrupt is enabled (ADIE = 1), the device will wake up from Sleep when the conversion completes. If the ADC interrupt is disabled (ADIE = 0), the device remains in Sleep and the ADC module is turned off, although the ON bit remains set.

When the ADC clock source is something other than the ADCRC, a SLEEP instruction causes the present conversion to be aborted and the ADC is turned off, although the ON bit remains set.