Building a multi-FPGA-based emulation framework to support networks-on-chip design and verification

In this article, we present a highly scalable, flexible hardware-based network-on-chip (NoC) emulation framework, through which NoCs built upon various types of network topologies, routing algorithms, switching protocols and flow control schemes can be explored, compared, and validated with injected or self-generated traffic from both real-life and synthetic applications. This high degree of scalability and flexibility is achieved due to the field programmable gate array (FPGA) design choices made at both functional and physical levels. At the functional level, a NoC system to be emulated can be partitioned into two parts: (i) the processing cores and (ii) the network. Each part is mapped onto a different FPGA so that when there is any change to be made to any one of these parts, only the corresponding FPGA needs to be reconfigured and the rest of the FPGAs will be left untouched. At the physical level, two levels of interconnects are adopted to mimic NoC on-chip communications: high bandwidth and low latency parallel on-board wires, and high-speed serial multigigabit transceivers available in FPGAs. The latter is particularly important as it helps the proposed NoC emulation platform scale well with the size increase of the NoCs.