An interface system includes a first driver module that communicates through a bus with a first peripheral card when the bus is in a first mode. A second driver module communicates through the bus with a second peripheral card when the bus is in a second mode. A bus control module receives a communication notification signal from the second peripheral card when the first peripheral card is communicating with the first driver module. The communication notification signal does not interfere with the communication of the first peripheral card and the first driver module. The bus control module switches the bus between first and second modes in response to the communication notification signal.