Path-Diversity-Aware Adaptive Routing in Network-on-Chip Systems

The partially adaptive routing plays an important role in the performance of Network-on-Chip (NoC). It uses information of the network to select a better path to deliver a packet. However, it may have imbalanced path diversity in different directions, which makes their tolerances of traffic load differ a lot from each other. This characteristic would cause problems in traffic balancing but give us extra information of the network. To achieve load balancing, in this paper, we present an adaptive routing scenario with Path-Diversity-Aware (PDA) and Augmented-PDA (A-PDA) selections, which use the information of path diversity. Moreover, we derive a formula to quantify the characteristic of path diversity. Experiments with different scenarios were conducted. The simulation results show that our proposed selections have an advantage over other selection functions in saturation throughput, with up to 36.84%, and have better scalability in large scale NoC. In addition, a low-cost router architecture is proposed to implement PDA and A-PDA and the synthesized results are also shown in this paper.