12.3.1 Idle and Interrupts
Idle mode ends when an interrupt occurs (even if GIE = 0), but IDLEN is not changed. The device can re-enter
Idle by executing the SLEEP instruction.
If Recover-on-Interrupt is enabled (ROI = 1), the interrupt that brings the device out of Idle
also restores full-speed CPU execution when Doze is also enabled.
