网格和环面NoCs中的高效旁路
Efficient Bypass in Mesh and Torus NoCs
摘要：
最小化延迟和功耗是NoC路由器设计的关键目标。不同的建议结合前瞻路由和路由器旁路跳过仲裁和缓冲，减少路由器延迟。然而，使用它们的条件要求中间路由器中的缓冲区完全为空。这限制了使用旁路流水线的微片的量，特别是在中等和高负载下，增加了延迟和功率。本文提出了NEBB，非空缓冲区旁路，一种机制，允许旁路微片，即使缓冲区旁路不为空。该机制适用于虫洞和虚拟切穿，它们各自具有不同的优点。NEBB-Hybrid提出在每种情况下采用最佳流量控制。该机制扩展到环面拓扑结构，使用FBFC和共享缓冲区。使用Booksim对这些建议进行了评估，结果显示单微片数据包的缓冲微片减少了75%，这意味着延迟和动态功耗分别减少了30%和23%。对于双峰流量，这些改善分别为20%和21%。此外，当使用共享缓冲器时，旁路利用率在很大程度上独立于VC的数量，并且与很少的私有缓冲器非常有竞争力，从而允许简化分配机制。
英文摘要：
Minimizing latency and power are key goals in the design of NoC routers. Different proposals combine lookahead routing and router bypass to skip the arbitration and buffering, reducing router delay. However, the conditions to use them requires completely empty buffers in the intermediate routers. This restricts the amount of flits that use the bypass pipeline especially at medium and high loads, increasing latency and power. This paper presents NEBB, Non-Empty Buffer Bypass, a mechanism that allows to bypass flits even if the buffers to bypass are not empty. The mechanism applies to wormhole and virtual-cut-through, each of them with different advantages. NEBB-Hybrid is proposed to employ the best flow control in each situation. The mechanism is extended to torus topologies, using FBFC and shared buffers. The proposals have been evaluated using Booksim, showing up to 75% reduction of the buffered flits for single-flit packets, which translates into latency and dynamic power reductions of up to 30% and 23% respectively. For bimodal traffic, these improvements are 20 and 21% respectively. Additionally, the bypass utilization is largely independent of the number of VCs when using shared buffers and very competitive with few private ones, allowing to simplify the allocation mechanisms.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
