Sleep Mode Operation

Writing the Run In Standby bit (RUNSTDBY) in the Control A register (CCL.CTRLA) to '1' will allow the system clock to be enabled in Standby sleep mode.

If RUNSTDBY is '0' the system clock will be disabled in Standby sleep mode. If the Filter, Edge Detector or Sequential logic are enabled, the LUT output will be forced to zero in Standby sleep mode. In Idle sleep mode, the TRUTH table decoder will continue operation and the LUT output will be refreshed accordingly, regardless of the RUNSTDBY bit.

If the Clock Source bit (CLKSRC) in the LUT n Control A register (CCL.LUTnCTRLA) is written to '1', the LUT input 2 (IN[2]) will always clock the Filter, Edge Detector and Sequential block. The availability of the IN[2] clock in sleep modes will depend on the sleep settings of the peripheral employed.