29.3.5 Sleep Mode Operation
In Idle Sleep mode, the AC will continue to operate as normal.
In Standby Sleep mode, the AC is disabled by default. If the Run in Standby Sleep mode bit (RUNSTDBY) in the Control A register (AC.CTRLA) is written to '1', the AC will continue to operate, but the Status register will not be updated, and no Interrupts are generated if no other modules request the CLK_PER, but events and the pad output will be updated.
In Power-Down Sleep mode, the AC and the output to the pad are disabled.