KNoCEmu: High Speed FPGA Emulator for Kilo-node Scale NoCs

Many-core architectures are becoming mainstream in both processor designs and System-on-Chip (SoC) designs. With the growing number of cores on a chip, Network-on-Chip (NoC) has become the de-facto on-chip communication infrastructure. Since it is believed that the near future many-core architectures will have thousands of cores integrated on a single chip, it is essential to have both full-system simulators and stand-alone NoC simulators for supporting architectural design exploration and performance evaluation of such kilo scale many-core systems. This paper proposes KNoCEmu, an FPGA emulator which can achieve fast and cycle-accurate Kilo-Node scale NoC simulations. To overcome the limitation of FPGA resources, we propose a method which reduces the amount of required FPGA resources while maintaining the simulation accuracy. The time-division multiplexing technique is adopted to emulate the behavior of the entire network using one or several physical nodes. Our design is optimized to efficiently use FPGA resources such as block RAM and distributed RAM. We have implemented KNoCEmu for emulating a 32×32 mesh NoC with the conventional input buffer router on a Virtex 7 XC7VX485T FPGA and evaluated the amount of occupied FPGA resources and the simulation speedup over a software-based software simulator. The evaluation results show that KNoCEmu can achieve 134× simulation speedup over the software-based simulator while using less than 8% of the total number of available slices of the Virtex 7 XC7VX485T FPGA.