Research Of Communications And Routing Mechanism For Networks On Chip

The continuous evolution of semiconductor technology enables billions of transistors to be integrated into a single silicon die. It is predicted that at the end of this decade, it will allow more and more IP cores integrated on a single chip. As the number of cores of system chip increased, traditional SoC design methodology will not fit the billion-transistor field design requirement. At this time NoC, as a new solution, is presented. The scalable ability of NoC well meets the challenge of new design requirement. NoC gradually becomes a new architecture besides traditional on-chip bus. In general, NoC is a kind of flexible and scalable micro-network on chip, of which the two main guild lines are the network throughput and the delay. The complexity of NoC is characterized by two main factors, one is the network topology, and the other one is routing algorithm. This thesis mainly introduced the popular routing techniques and algorithms for NoC. At the same time, a multicast communications model is proposed for 2D Torus topology; and an adaptive routing algorithm is proposed for 2D Mesh topology.The main work in this thesis is as follows:(1) This thesis introduced the technical background and current scientific research situation of NoC; and introduced the topology of NoC, the structure of communication node, the switching techniques and the routing algorithms for NoC.(2) A model of multicast communications is proposed for NoC to provide communications to guarantee deadlock-free routing. Multicast model has the capability of reducing traffic remarkably, increasing utilization ratio of channels and decreasing testing time in test mode. Modeling of the multicast communications were simulated and applied on 2D Torus NoC. Experimental results demonstrate that our communications model has lower average communication latency and higher throughput than unicast communications.(3) A preconcerted wormhole routing algorithm is proposed for NoC to provide adaptive routing to guarantee deadlock-free and congestion-avoidance routing. Router architecture and flit (flow control unit) format are developed to support our routing algorithm. Modeling of the router and the routing algorithm were simulated and applied on 2D mesh NoC. Experimental results demonstrated that our routing algorithm has lower average communication latency than other routing algorithms such as XY,Odd-even,AntNet in condition of high throughout rate.