FERIVer: An FPGA-assisted Emulated Framework for RTL Verification of RISC-V Processors

Processor design and verification require a synergistic approach that combines instruction-level functional simulations with precise hardware emulations. The trade-off between speed and accuracy in the instruction set simulation poses a significant challenge to the efficiency of processor verification. By tapping the potentials of Field Programmable Gate Arrays (FPGAs), we propose an FPGA-assisted System-on-Chip (SoC) platform that facilitates cross-verification by the embedded CPU and the synthesized hardware in the programmable fabrics. This method accelerates the verification of the RISC-V Instruction Set Architecture (ISA) processor at a speed of 5 million instructions per second (MIPS), which is 150x faster than the vendor-specific tool (Xilinx XSim) and a 35x boost to the state-of-the-art open-source verification setup (Verilator). With less than 7\% hardware occupation on Zynq 7000 FPGA, the proposed framework enables flexible verification with high time and cost efficiency for exploring RISC-V instruction set architectures.