A bufferless network-on-chip (NoC) can deliver high energy efficiency, but such a NoC is subject to growing deflection when its traffic load rises. This article proposes Deflection Containment (DeC) for the bufferless NoC to address its notorious shortcomings of excessive deflection for performance improvement and energy savings. With multiple subnetworks bridged by an added link between two corresponding routers, DeC lets a contending flit in one subnetwork be forwarded to another subnetwork instead of deflected. Microarchitecture of DeC routers is rectified to shorten the critical path and lift network bandwidth. Its Cadence RTL implementations with a $15-nm$15-nm process are conducted respectively for mesh-based NoCs and torus-based NoCs. Additionally, different sized DeC-NoCs are evaluated extensively and compared with previous bufferless designs (BLESS and MinBD), uncovering that DeC with two bridged subnetworks (dubbed DeC2) for 8X8 mesh-based NoCs can lower deflection drastically by some 90 percent and energy consumption by upto 51 percent under real benchmark traffic loads, in comparison to BLESS. Under various synthetic traffic models and workloads, 16X16 torus-based DeC2-NoC sustains up to 2.33X loads when compared with its mesh-based counterpart, exhibiting the same clock rate and taking only negligible more power and area according to our full layout results.

中文翻译：

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具有桥接多个子网的无缓冲片上网络，可减少偏转和节能

无缓冲片上网络 (NoC) 可以提供高能效，但是当其流量负载增加时，这种 NoC 会受到越来越大的偏转。本文为无缓冲 NoC 提出了偏转遏制 (DeC)，以解决其过大偏转的臭名昭著的缺点，以提高性能和节省能源。由于多个子网由两个相应路由器之间的附加链路桥接，DeC 允许将一个子网中的竞争 flit 转发到另一个子网，而不是偏转。修正DeC路由器的微架构，缩短关键路径，提升网络带宽。它的 Cadence RTL 实现具有$15-nm$15——n米分别对基于网格的 NoC 和基于环面的 NoC 进行处理。此外，对不同大小的 DeC-NoC 进行了广泛评估，并与之前的无缓冲设计（BLESS 和 MinBD）进行了比较，发现带有两个桥接子网络（称为 DeC2）的 DeC 可用于基于 8X8 网格的 NoC 可将偏转大幅降低约 90% 并降低能耗与 BLESS 相比，在实际基准流量负载下高达 51%。在各种合成流量模型和工作负载下，与基于网格的对应物相比，基于 16X16 环面的 DeC2-NoC 可承受高达 2.33 倍的负载，表现出相同的时钟速率，并且根据我们的完整布局结果，仅占用微不足道的更多功率和面积。