4.13.2.2 External Pin Wake-up

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This section applies to devices of revision C2 and earlier.

The device may be configured to wake from SLEEP when a valid pulse on the WAKE_IN/WAKE_IO pin, as specified by the OPEN Alliance 10BASE‑T1S Sleep/Wake‑Up Specification is detected. After receipt of a valid signal, the INH pin is driven high to the VDDAU supply to re-enable external power supplies and wake the system. See Wake-up Signal Characteristics and Timing - Rev C2 for details.

Wake-up via the WAKE_IN/WAKE_IO pin is enabled by writing a ‘1’ to the WAKE_IN Enable (WKINEN) bit in the Sleep Control 0 (SLPCTL0) register prior to entering the SLEEP state. The Wake In Polarity (WIPOL) bit in the Sleep Control 1 (SLPCTL1) register selects whether this signal is active high or low.

Restriction: Assertion of the WAKE_IN pin is only detectable when the device is in the SLEEP state. When awake and in ACTIVE state the device will not detect pulse assertions on the WAKE_IN pin.
Important: When wake from WAKE_IN is enabled, the device will not enter the SLEEP state while the WAKE_IN input is asserted. The WAKE_IN pin must be deasserted before the Sleep Inhibit Delay will occur followed by the INH pin being released and the SLEEP state entered. See the section Sleep Mode and System Power Management for more details.