LiPaR: A light-weight parallel router for FPGA-based networks-on-chip

ABSTRACT

Present day technology for ASICs supports Networks-on-Chip designs which can have 100 million gates on a single chip. The latest FPGAs can support only about 10 million gates to accomodate all logic and the associated routing. In order to implement a competitive NoC architecture in FP-GAs, the area occupied by the network should be kept to a minimum. This ensures that the maximum area can be utilized by the logic while maintaining the performance of the router network. Reducing area also reduces the power consumption. In this paper, we implement a parallel router which can support five simultaneous routing requests at the same time with an area overhead of only 352 Xilinx Virtex-II Pro FPGA slices (2. 57% of XC2VP30). We introduce optimizations in XY routing and decoding logic thereby gaining in area and performance. The header overhead is 8 bits per packet and the packet size can vary between 16 and 128 bits. We also implement a 3 x 3 mesh network with a total area overhead of 28% leaving 72% of the area available for the logic in a Virtex-II Pro XC2VP30 device. We characterize the router and several mesh networks for power and performance parameters.

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INDEX TERMS

Primary Classification:
  B. Hardware
  B.4 INPUT/OUTPUT AND DATA COMMUNICATIONS
      B.4.3 Interconnections (subsystems)
          Subjects: Interfaces

General Terms:
Design, Experimentation

Keywords:
FPGA, SoCRouter, networks-on-chip