Abstract: IEEE1394 bus is a high performance commercial bus standard. Today, it is gradually used in avionics. So it is necessary to study the fault tolerance of IEEE1394 to meet the avionics reliability and performance requirements. In this paper, the study is focused on the fault tolerance of PHY/link interface. All kinds of fault possibly presented in the interface signals between physical layer and link layer under PHY control, were analyzed. The techniques of how to
avoid these faults for serious damage to avionics were provided.