Comparative Analysis of Lightweight Arbiters for Mesh NoCs

One of the key mechanisms for ensuring quality of service (QoS) is arbitration, which determines the order of access to shared resources of a network-on-chip (NoC). This paper provides a comparative analysis of lightweight arbiters that consider the number of hops from the source address and the remaining hop distance to the destination address. The study was performed using the Noxim simulator for networks with a mesh topology. Various traffic patterns, routing algorithms, and network congestion levels were considered. The results show that hopcount-max is the most effective arbiter on average, providing the best results in half of the considered routing scenarios. It achieves the highest throughput under medium and high load and improves throughput over round-robin by 30% under random traffic and by 15% under shuffle traffic. Under transpose traffic, hopcount-min and distance-min reduce average delay by 60% relative to round-robin. Round-robin remains preferable in terms of maximum delay under light load. The results obtained can be used in the design of lightweight arbiters and QoS optimization in promising NoCs.