4.13.3 Entering Sleep Mode

After wake-up has been configured, the device may at any time be commanded to enter the SLEEP state. This may be done in one of two ways. The host controller may initiate a transition to SLEEP by writing a ‘1’ to the Sleep Enable (SLPEN) bit in the Sleep Control 0 (SLPCTL0) register. Alternatively, the device may also be configured to enter SLEEP automatically upon expiration of an inactivity watchdog as detailed below.