SMART NoC, which transmits unconflicted flits to distant processing elements (PEs) in one cycle through the express bypass, is a high-performance NoC design proposed recently. However, if contention occurs, flits with low priority would not only be buffered but also could not fully utilize bypass. Although there exist several routing algorithms that decrease contentions by rounding busy routers and links, they cannot be directly applicable to SMART since it lacks the support for arbitrary-turn (i.e., the number and direction of turns are free of constraints) routing. Thus, in this article, to minimize contentions and further utilize bypass, we propose an improved SMART NoC, called ArSMART, in which arbitrary-turn transmission is enabled. Specifically, ArSMART divides the whole NoC into multiple clusters where the route computation is conducted by the cluster controller and the data forwarding is performed by the bufferless reconfigurable router. Since the long-range transmission in SMART NoC needs to bypass the intermediate arbitration, to enable this feature, we directly configure the input and output ports connection rather than apply hop-by-hop table-based arbitration. To further explore the higher communication capabilities, effective adaptive routing algorithms that are compatible with ArSMART are proposed. The route computation overhead, one of the main concerns for adaptive routing algorithms, is hidden by our carefully designed control mechanism. Compared with the state-of-the-art SMART NoC, the experimental results demonstrate an average reduction of 40.7% in application schedule length and 29.7% in energy consumption.

中文翻译：

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ArSMART：支持任意转弯传输的改进型 SMART NoC 设计

SMART NoC 是最近提出的一种高性能 NoC 设计，它在一个周期内通过快速旁路将无冲突的迁移传输到远处的处理元件 (PE)。但是，如果发生争用，低优先级的flit 不仅会被缓冲，而且不能充分利用旁路。虽然有几种路由算法通过舍入繁忙的路由器和链路来减少争用，但它们不能直接应用于 SMART，因为它缺乏对任意转弯（即转弯的数量和方向不受约束）路由的支持。因此，在本文中，为了尽量减少争用并进一步利用旁路，我们提出了一种改进的 SMART NoC，称为 ArSMART，其中启用了任意转弯传输。具体来说，ArSMART 将整个 NoC 划分为多个集群，其中路由计算由集群控制器进行，数据转发由无缓冲可重构路由器完成。由于 SMART NoC 中的远程传输需要绕过中间仲裁，为了启用此功能，我们直接配置输入和输出端口连接，而不是应用基于逐跳表的仲裁。为了进一步探索更高的通信能力，提出了与 ArSMART 兼容的有效自适应路由算法。路由计算开销是自适应路由算法的主要关注点之一，被我们精心设计的控制机制隐藏了。与最先进的 SMART NoC 相比，实验结果表明平均减少了 40。