Network-on-Chip (NoC) is widely adopted in neuromorphic processors to support communication between neurons in spiking neural networks (SNNs). However, SNNs generate enormous spiking packets due to the one-to-many traffic pattern. The spiking packets may cause communication pressure on NoC. We propose a path-based multicast routing method to alleviate the pressure. Firstly, all destination nodes of each source node on NoC are divided into several clusters. Secondly, multicast paths in the clusters are created based on the Hamiltonian path algorithm. The proposed routing can reduce the length of path and balance the communication load of each router. Lastly, we design a lightweight microarchitecture of NoC, which involves a customized multicast packet and a routing function. We use six datasets to verify the proposed multicast routing. Compared with unicast routing, the running time of path-based multicast routing achieves 5.1x speedup, and the number of hops and the maximum transmission latency of path-based multicast routing are reduced by 68.9% and 77.4%, respectively. The maximum length of path is reduced by 68.3% and 67.2% compared with the dual-path (DP) and multi-path (MP) multicast routing, respectively. Therefore, the proposed multicast routing has improved performance in terms of average latency and throughput compared with the DP or MP multicast routing.

片上网络 (NoC) 广泛应用于神经形态处理器中，以支持尖峰神经网络 (SNN) 中神经元之间的通信。然而，由于一对多的流量模式，SNN 会生成巨大的尖峰数据包。尖峰报文可能会对NoC造成通信压力。我们提出了一种基于路径的组播路由方法来减轻压力。首先，将NoC上每个源节点的所有目的节点划分为若干个簇。其次，基于哈密顿路径算法创建簇内的组播路径。所提出的路由可以减少路径长度并平衡每个路由器的通信负载。最后，我们设计了一个轻量级的NoC微架构，其中包括定制的组播数据包和路由功能。我们使用六个数据集来验证所提出的多播路由。与单播路由相比，基于路径的组播路由的运行时间实现了5.1倍的加速，并且基于路径的组播路由的跳数和最大传输延迟分别降低了68.9%和77.4%。与双路径（DP）和多路径（MP）组播路由相比，最大路径长度分别减少了68.3%和67.2%。因此，与DP或MP组播路由相比，所提出的组播路由在平均延迟和吞吐量方面具有改进的性能。