31.3.4 Sleep Mode Operation
Writing the Run In Standby (RUNSTDBY) bit
            in the Control A (CCL.CTRLA) register to ‘1’ will allow the selected
            clock source to be enabled in Standby sleep mode.
If RUNSTDBY is ‘0’, the
            peripheral clock will be disabled in Standby sleep mode. If the filter, edge detector,
            and/or sequencer are enabled, the LUT output will be forced to ‘0’ in
            Standby sleep mode. In Idle sleep mode, the TRUTH table decoder will continue the
            operation, and the LUT output will be refreshed accordingly, regardless of the RUNSTDBY
            bit.
If the Clock Source (CLKSRC) bit in the LUT n Control A (CCL.LUTnCTRLA) register is
            written to ‘1’, the LUTn-TRUTHSEL[2] will always clock the filter, edge
            detector, and sequencer. The availability of the LUTn-TRUTHSEL[2] clock in sleep modes
            will depend on the sleep settings of the peripheral used.
