On-chip Network Switch Fabric

Network on Chip (NoC) is proposed to solve the communication bottleneck in System on Chip (SoC). In NoC design flow, we consider not only network performance but also the implemention cost, e.g. area overhead and power consumption. Router architecture is one of the important factors for NoC performance, area and power, so router design is one of the key techniques for NoC design.In this thesis, we first introduce some techniques in NoC area, sunch as topology, routing algorithm and switching technique. After a short discussion of these techniques, we propose a low resource overhead and low power consumption router architecture for two-dimensional NoC (2D NoC), which is reffered as virtual output queue (VOQ) router. The simulation results show that VOQ router based NoC achieves lower latency comparing with traditional virtual channel (VC) router in 8×8 Mesh NoC platform when the traffic load is light.With the devloppment of three-dimensional integrate circuits (3D IC), high performance router architecture for 3D NoC becomes more and more research interests. One of the important characteristics of 3D NoC is that inter-wafer wires are much shorter than intra-wafer ones. Based on the property of 3D NoC, we propose a high performance router in this thesis which is called dual flit transmission rate (DFTR) router, because inter-wafer transmission rate is much higher than intra-wafer transmission rate in DFTR router based 3D NoC. According to experiment results, DFTR based 3D NoC gets lower packet average latency and higher throughput in 4×4×4 Mesh and 2×2×8 Mesh NoC platform,Prototyping can achieve practical performance evaluation for the NoC studies. We realize the VOQ router for the NoC evaluation platfrom, which is supported with the 863 project"Multi-processor Array Based SDR Implemention". Xilinx Virtex-4 FPGA is used as the hardware platform, and Verilog HDL, Xilinx ISE are used as the development tools in the project. The prototyping study shows that the proposed VOQ router can achieve good performance and be used in the practical developments.