A Fault-Tolerant Routing Algorithm Using Tunnels in Fault Blocks for Network-on-Chip

In 2D mesh Network on Chips (NoCs), fault-tolerant algorithms usually deactivate healthy nodes to form rectangular or convex fault blocks. However, the deactivated nodes can possibly form an available tunnel in a faulty block. We propose a method to discover these tunnels, and propose a fault-tolerant routing algorithm to route messages through such paths such that the overall communication performance is improved. In addition, the algorithm is deadlock-free by prohibiting some turns. Simulation results demonstrate that the reuse of the sacrificed nodes in fault blocks can significantly reduce the average message latency.