The eSPI Target has an Alert Mode bit in its General Capabilities and Configuration register, which selects between the discrete and in-band Alert# indications. For a single Initiator – single Target configuration, the default value of this bit (in-band Alert#) works as-is. When two or more targets are present, this bit must be set to 1 by the eSPI Initiator to ensure that Alert# is signaled by discrete pins (one per target).