A speculative arbiter design to enable high-frequency many-VC router in NoCs

High-performance network-on-chip routers usually prefer a large number of Virtual Channels (VC) for high throughput. However, the growth in VC count results in increased arbitration complexity and reduced router clock frequency. In this paper, we propose a novel high-frequency many-input arbiter design for many-VC routers. It is based on the speculation on short and thus fast arbitrations in case of high VC occupancy. We further enhance it to reduce arbitration latency and promote speculation opportunity. Simulation results show that using the proposed arbiter, a 16-VC router achieves almost the same performance as an ideal design, showing improvements of around 48% on zero-load latency and 100% on network throughput over a naive 16-VC design.