RISC-V based implementation of Programmable Logic Controller on FPGA for Industry 4.0

This paper presents a RISC-V based architecture for implementing Programmable Logic Controller (PLC) on Field Programmable Gate Array (FPGA). The proposed architecture makes efficient use of FPGA flexibility and performance to implement PLCs that are ready for Industry 4.0 The proposed method starts by converting Instruction List (IL) complying to IEC 61131-3 standard into a processing system consisting of RISC-V processor and connected peripherals according to the IL program. A use case based on RISC-V processor is implemented, simulated and tested. Selected Function Blocks (FB) have been developed on RTL and implemented on FPGA along with the RISC-V core to enhance the overall execution speed, thus allowing for parallel execution of non-interlocking instructions. A special compiler is developed in this work to handles the IL conversion into SRAM Object File (SOF) downloaded directly to FPGA. The proposed solution is tested with some fundamental IL commands, long IL programs, and basic function blocks on Altera C5G FPGA development kit.