To put the device into a sleep mode, follow these steps:
Configure and enable the interrupts
that should wake up the device from sleep. Also enable global interrupts.
Warning: If there are no
interrupts enabled when going to sleep, the device cannot wake up again. Only a
reset will allow the device to continue operation.
Select the sleep mode to be entered
and enable the Sleep Controller by writing to the Sleep Mode bits (SMODE) and the
Enable bit (SEN) in the Control A register (SLPCTRL.CTRLA). A SLEEP instruction must
be run to make the device actually go to sleep.