Real-time Processor Interconnection Network for FPGA-based Multiprocessor System-on-Chip (MPSoC)

This paper introduces a new approach for a network on chip (NOC) design which is based on a NlogN interconnect topology. The intended application area for the NOC is the real-time communication of multiprocessors that are hosted by a single Field Programmable Gate Array (FPGA). The proposed NOC is an on-chip multistage interconnection network for which an upper limit can be guaranteed that is at most needed for the latency while delivering data between sending and receiving processors. The reason for the deterministic interprocessor communication is the constant path length from input to any output port of the NOC. In contrast to contemporary NOCs, no intermediate routers exist. Thus, no overloaded router with hot spot problems can occur, and the proposed NOC can be used for real-time applications. Example NoCs of size 4x4 and 8x8 were implemented in VDHL, together with their softcore processors on Spartan3 and Virtex-4 and -5 FPGAs from Xilinx. Keywords–network on chip; multistage interconnection network; softcore processor; real-time multiprocessor; FPGAbased multiprocessor