Research Of Routing Algorithms In Network On Chip (NoC)

The interconnect by bus in SoC(System on Chip) has already be the bottleneck of performance and Network-on-Chip (NoC), as a new way to solve the problems of SoC, has been given more and more attention. And as the two main terms of NoC, the topology and the routing algorithm is the focus. Mesh, which has the characters of regularity, controlled electric and easy to collocation, is the most popular topology of NoC. So the researches of the routing algorithms of NoC in this paper are based on mesh. The main work and contribution of the paper are as follows:1. Considering the advantage of the existing deterministic and adaptive routing algorithms, SD (Static and Dynamic), which is combined with the above ones, is proposed. When the network traffic load increases, the center region of the mesh may be congestive and the center nodes would become hotspots. This causes the problem of severely performance degradation. The SD is used to solve such a problem. SD is more adaptive compared with the deterministic routing algorithms and much better in cost than the adaptive ones. Performance of SD is evaluated by OPNET and the results show that SD achieves better performance than XY and Dyxy.2. RR (Routing with Region Information) is proposed to reduce the distance of the remote communication nodes in mesh. In RR, the network is consisted of many sub-regions and the center node in each sub-region form a litter mesh. Every sub-region communicates with the others via its center nodes. The simulation results in OPNET show that RR gets lower network delay and higher network throughput.3. By using the predictability of communication behavior among nodes in NoC and based on the researches of Application Specification, RR is applied to Application Specification. Generic steps to implement Application Specification are given in the paper. The nodes with many and frequent communication tasks are mapped into center nodes in each sub-region because they have larger buffer space and more bandwidth. After optimizing the mapped relation between the communication nodes and the topology, we can solve the main communication delay, which can do much benefit to improve the performance of the whole network.