C-Routing: An adaptive hierarchical NoC routing methodology

Deterministic routing algorithms are easier to design and implement in NoC but these fail to adapt to congestion. Table based adaptive routing solutions are not scalable. As the number of nodes increases, the area required for routing table becomes a penalty. In this paper, we propose a new hierarchical cluster based adaptive routing called `C-Routing´ in 2-D Mesh NoC. The solution reduces routing table size and provides deadlock freedom without use of virtual channels while ensuring livelock free routing. Routers in our method use intelligent routing to route information between the processing elements ensuring the correctness, deadlock freeness, and congestion handling. This method has been evaluated against other adaptive algorithms such as PROM, and Q-Routing etc. Results show that the proposed method performs better for given traffic patterns. C-routing uses adaptivity to avoid congestion by uniform distribution of traffic among the cores by sending flits over two different paths to the destination.