Fault-Tolerant Networks-on-Chip Routing With Coarse and Fine-Grained Look-Ahead
Fault-Tolerant Networks-on-Chip Routing With Coarse and Fine-Grained Look-Ahead
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DOI：
10.1109/tcad.2015.2459050
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发表时间：
2016-02
影响因子：
2.9
通讯作者：
Junxiu Liu;J. Harkin;Yuhua Li;L. Maguire
中科院分区：
文献类型：
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作者：
Junxiu Liu;J. Harkin;Yuhua Li;L. Maguire
由于先进制造工艺中物理缺陷的增加，容错和自适应能力是现代片上网络（NoC）面临的挑战。提出了两种新的自适应路由算法，即粗粒度和细粒度（FG）前瞻算法，以提高2-D网状/环面NoC系统的容错能力。这些策略利用相邻节点的故障标志码来获取片上网络区域内实时流量的状态或状况，然后计算路径权值并选择路由转发数据包。这种方法使路由器能够最大限度地减少相邻连接通道的拥塞，并通过提前查看远距离的相邻路由器路径来绕过具有故障通道的路径。所提出的路由算法的新奇在于加权路径选择策略，它可以做出接近最优的路由决策，以在高故障率下保持NoC系统性能。实验结果表明，在不同的业务负载和高故障率下，所提出的路由算法与其他现有的路由算法相比，性能都有较大的提高。在复杂故障模式下，与粗粒度方法相比，具有FG前瞻能力的路由算法实现了更高的吞吐量。两种路由方法的硬件面积/功耗相对较低，这并不妨碍大规模NoC实现的可扩展性。
Fault tolerance and adaptive capabilities are challenges for modern networks-on-chip (NoC) due to the increase in physical defects in advanced manufacturing processes. Two novel adaptive routing algorithms, namely coarse and fine-grained (FG) look-ahead algorithms, are proposed in this paper to enhance 2-D mesh/torus NoC system fault-tolerant capabilities. These strategies use fault flag codes from neighboring nodes to obtain the status or conditions of real-time traffic in an NoC region, then calculate the path weights and choose the route to forward packets. This approach enables the router to minimize congestion for the adjacent connected channels and also to bypass a path with faulty channels by looking ahead at distant neighboring router paths. The novelty of the proposed routing algorithms is the weighted path selection strategies, which make near-optimal routing decisions to maintain the NoC system performance under high fault rates. Results show that the proposed routing algorithms can achieve performance improvement compared to other state of the art works under various traffic loads and high fault rates. The routing algorithm with FG look-ahead capability achieves a higher throughput compared with the coarse-grained approach under complex fault patterns. The hardware area/power overheads of both routing approaches are relatively low which does not prohibit scalability for large-scale NoC implementations.