4.14.4.3 Manual Wake Assertion

This section applies to devices of revision D0 and later.

Any time that the LAN8670/1 is powered up in the ACTIVE state, the host controller may trigger a wake-up event to be sent to the network and/or additional devices.

This event can be configured to be a wake signal generated on the MDI (see MDI Wake Forwarding), a pulse on either WAKE_OUT or WAKE_IO (see Using a Pin for Wake Forwarding) or both.

Once configuration is completed, there are two ways to implement manual wake assertion:

Using the OPEN Alliance WS_CTRL Register

A wake forward event can be activated by writing a ‘1’ to the Generate Low Power Mode Exit Request (LPEXIT) bit in the WS_CTRL register. Once the wake events have completed, the device will clear the LPEXIT bit.
Using the SLPCTL1 Register for Backwards Compatibility

A wake forward event can be activated by writing a ‘1’ to the Manual Wake Forward (MWKFWD) bit in the Sleep Control 1 (SLPCTL1) register. Use a read-modify-write sequence to maintain the configured wake signaling. Once the wake events have completed, the device will clear the MWKFWD bit, but the forwarding enable bits will hold their values.