A Hotspot-Pattern-Aware Routing Algorithm for Networks-on-Chip

The Networks-on-Chip (NoC) is widely accepted as an advanced on-chip system which replaces the traditional bus structure. NoC is promising as a solution for future many-core chip processor with better scalability and flexibility. Routers in NoC make the routing decision based on the routing algorithm. Many routing algorithms have been proposed to improve the performance of NoC. Some routing algorithms only have superiority under a specific traffic pattern, but they can have poor performance under other traffic patterns. Compared to uniform traffic, some complex hotspot patterns are closer to reality. Traffic-aware routing algorithms are designed to solve this problem. These traffic-aware routing algorithms commonly utilize virtual channels (VC) or routing tables to predict the future traffic distribution, which will have large power and hardware overheads that cannot be ignored. To solve these problems, a VC-free traffic-pattern-aware routing algorithm based on West-first routing and North-last routing is proposed in this paper. This algorithm contains a hotspot node and hotspot pattern detecting mechanism, which were designed to improve the performance of NoCs under different traffic patterns. A hotspot information block which has a small cost is connected to each router to deal with the hotspot information and detect the hotspot patterns. The simulation results show that routing algorithm proposed combines the advantages of the two existing routing algorithms and has better performance when considering different traffic patterns.