Designing RISC-V CPU in Verilog and its FPGA Implementation

Understanding RISC-V ISA (RV32I), Verilog implementation of custom RISC-V CPU, LED GPIO, UART and porting to FPGA

Designing RISC-V CPU in Verilog and its FPGA Implementation
Designing RISC-V CPU in Verilog and its FPGA Implementation

Designing RISC-V CPU in Verilog and its FPGA Implementation free download

Understanding RISC-V ISA (RV32I), Verilog implementation of custom RISC-V CPU, LED GPIO, UART and porting to FPGA

This comprehensive course, "Designing RISC-V CPU in Verilog and its FPGA Implementation",  offers a deep dive into the fascinating world of custom processor design, focusing on the open-source RISC-V instruction set architecture (ISA). Participants will gain hands-on experience in architecting, describing, and implementing a functional RISC-V CPU core using the Verilog Hardware Description Language (HDL) and deploying it on Field-Programmable Gate Arrays (FPGAs).

The course begins by establishing a strong foundation in digital logic design principles and reviewing essential Verilog constructs relevant to complex digital systems. We will then introduce the RISC-V ISA (RV-32I), exploring its modularity, extensibility, and key instruction formats. Students will learn how to interpret the ISA specifications and translate them into hardware logic.

This course also provides step-by-step guidelines to set up the RISC-V toolchain, including assembler and GCC compiler, to write an embedded-C programme and compile it to Hex code, which will be loaded into an FPGA to access peripherals such as LEDs and UART.

A significant portion of the course is dedicated to the step-by-step design of a single-cycle RISC-V CPU. Topics covered will include:

  • Instruction Fetch Unit: Designing the program counter and instruction memory interface.

  • Decode Unit: Implementing instruction decoding logic, register file access, and control signal generation.

  • Execute Unit: Building the Arithmetic Logic Unit (ALU) and handling data path operations.

  • Memory Unit: Designing data memory interfaces for load and store operations.

  • Write-back Unit: Updating the register file with computed results.

  • Control Unit: Developing the finite state machine (FSM) or combinational logic to orchestrate CPU operations.

Emphasis will be placed on best practices in Verilog coding for synthesis, including modular design, parameterization, and robust test bench creation. Students will learn how to simulate their Verilog designs using industry-standard tools to verify functional correctness at each stage of the CPU development.

The latter part of the course focuses on the practical aspects of FPGA implementation. Participants will learn how to:

  • Synthesize their Verilog CPU design into a gate-level netlist.

  • Perform Place and Route to map the design onto specific FPGA resources.

  • Generate bitstreams for programming the FPGA.

  • Debug and test their implemented CPU on actual FPGA hardware, often by integrating peripherals like LEDs and UART for basic I/O and interaction.

By the end of this course, students will not only have a thorough understanding of RISC-V architecture and CPU design principles but also possess the practical skills to bring a complex digital design from concept to a working hardware implementation on an FPGA. This knowledge is invaluable for careers in embedded systems, custom silicon design, hardware acceleration, and research in computer architecture. A basic understanding of digital logic and Verilog is recommended.

Note: Only Base Integer Instruction (RV32I) is discussed and implemented in Verilog and FPGA. Also, you need one FPGA board for the hardware implementation of CPU. A basic FPGA board, such as Tang-9K, is sufficient for this.