MAFA: Adaptive Fault-Tolerant Routing Algorithm for Networks-on-Chip

While Networks-on-Chip have been increasing in popularity with industry and academia, it is threatened by the decreasing reliability of aggressively scaled transistors. This level of failure has architectural level ramifications, as it may cause an entire on-chip network to fail. Traditional fault-tolerant routing algorithms can overcome the faulty links or routers by rerouting packets around faulty regions. These approaches increase the packet latency and create congestion around the faulty region. In this paper, we present a novel fault-tolerant method that is able to route packets through shortest paths in the presence of faulty links, as long as a path exists. Although the same idea can be applied to a network with any number of virtual channels, we utilize two virtual channels to tolerate all one and two faulty links. Finally, the method is extended to support multiple faulty links by fully utilizing all allowable turns in the network.