Hi, I found the answer to my original question. I found the "Data Link Layer State Changed Enable" bit in the Slot Control register which seems to provide interrupt on link state changes. 6.7.3.3. Data Link Layer State Changed Events ============================================== The Data Link Layer State Changed event provides an indication that the state of the Data Link Layer Link Active bit in the Link Status register has changed. Support for Data Link Layer State Changed events and software notification of these events are required for hot-plug capable Downstream Ports. If this event is supported, the Port sets the status field associated with the event 5 when the value in the Data Link Layer Link Active bit changes. Thanks a bunch! Rajat