11.3.1 Initialization

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.