Efficient Congestion-Oriented Custom Network-on-Chip Topology Synthesis

We propose a new custom Network-on-Chip (NoC) topology synthesis methodology consisting of floor planning, routers assignment, and routing paths calculation steps. The proposed heuristic methodology integrates fast algorithms based on the B*-tree representation for floor planning, on bipartite matching for the routers assignment step, and on multi commodity flow for congestion minimization for the routing paths calculation step. Hence, it is able to explore a large portion of the solution space efficiently. Network performance is estimated using an integrated cycle-accurate simulator. Experimental results demonstrate that custom irregular NoC topologies can achieve latencies comparable to those achieved by 2-layer 3D regular mesh topologies. The multi commodity flow based routing paths calculation is proven to be effective in improving the average latency at high packet injection rates.