Naxim: A Fast and Retargetable Network-on-Chip Simulator with QEMU and SystemC

Systems-on-Chip (SoC) architectures have been shifting from single-core to multi-core solutions, and they are at present evolving towards many-core ones. Network-on-Chip (NoC) is considered as a promising interconnection scheme for many-core SoCs since it offers better scalability than traditional bus-based interconnection. In this work, we have developed a fast simulator of NoC architectures using QEMU and SystemC. QEMU is an open-source CPU emulator which is widely used in many simulation platforms such as Android Emulator. In the proposed simulator, each CPU core is emulated by a QEMU, and the network part including NoC routers is modeled with SystemC. The SystemC simulator and QEMUs are connected by TCP sockets on a host computer. Our simulator is fast because QEMUs run in parallel on a multi-core host computer or even multiple host computers. Also, our simulator is highly retargetable because QEMU provides a variety of CPU models and we use QEMU as is. In our experiments, our simulator successfully simulates a 108-core NoC in a practical time. We have also confirmed the scalability and retargetability of our NoC simulator.