The aggressively scaled CMOS technology is increasingly threatening the dependability of network-on-chips (NoCs) architecture. In a mesh-based NoC, a faulty router or broken link may isolate a well functional processing element (PE). Also, a set of faulty routers may form isolated regions, which can degrade the design. In this paper, we propose a router-level redundancy (RLR) fault-tolerant scheme that differs from the traditional microarchitecture-level redundancy (MLR) approach to relieve the problem of isolated PE and isolated region. By simply adding one spare router within each router set in a mesh, RLR can be created and connection paths between adjacent routers can be diversified. To exploit this extra resource, two reconfiguration algorithms are demonstrated to detour observed faulty routers/links. The proposed RLR fault-tolerant scheme can tolerate at most one faulty router within a router set. After the reconfiguration, the original mesh topology is maintained. As a result, the proposed architecture does not need any support from the network layer routing algorithms. The scheme has been evaluated based on the three fault-tolerant metrics: reliability, mean time to failure (MTTF), and yield. The experimental results show that the performance RLR increases as the size of NoC grows; however, the relative connection cost decreases at the same time. This characteristic makes our architecture suitable for large-scale NoC designs.

大规模扩展的CMOS技术正日益威胁片上网络（NoC）体系结构的可靠性。在基于网格的NoC中，有故障的路由器或断开的链路可能会隔离功能良好的处理元件（PE）。同样，一组故障路由器可能会形成隔离区域，这可能会使设计质量下降。在本文中，我们提出了一种路由器级冗余（RLR）容错方案，该方案不同于传统的微体系结构级冗余（MLR）方法，以缓解隔离的PE和隔离区域的问题。通过在网格中的每个路由器集中简单地添加一个备用路由器，可以创建RLR，并且可以使相邻路由器之间的连接路径多样化。为了利用此额外资源，演示了两种重新配置算法来绕过观察到的故障路由器/链路。提出的RLR容错方案最多可以容忍一个路由器集中的一个故障路由器。重新配置后，将保留原始的网格拓扑。结果，所提出的体系结构不需要网络层路由算法的任何支持。该方案已基于三个容错指标进行了评估：可靠性，平均故障时间（MTTF）和良率。实验结果表明，随着NoC尺寸的增加，RLR的性能也随之提高。但是，相对连接成本同时降低。这一特性使我们的架构适合于大规模NoC设计。所提出的体系结构不需要网络层路由算法的任何支持。该方案已基于三个容错指标进行了评估：可靠性，平均故障时间（MTTF）和良率。实验结果表明，随着NoC尺寸的增加，RLR的性能也随之提高。但是，相对连接成本同时降低。这一特性使我们的架构适合于大规模NoC设计。所提出的体系结构不需要网络层路由算法的任何支持。该方案已基于三个容错指标进行了评估：可靠性，平均故障时间（MTTF）和良率。实验结果表明，随着NoC尺寸的增加，RLR的性能也随之提高。但是，相对连接成本同时降低。这一特性使我们的架构适合于大规模NoC设计。