A Hardware based RISC-V Extension Instruction Implementation Mechanism and Implementation Example

The RV32I instruction set of RISC-V is particularly suitable for use as an instruction set for network processors. This paper can greatly enhance the power of the RV32I instruction set by using extended instructions. Better suited for handling some complex functions of network processors. The paper also provides the implementation of extended instructions for two types of operations: flow table lookup and checksum calculation. Through a complete implementation process and details, it comprehensively demonstrates how to effectively use the extension instructions of RV32I to achieve common operations of smart network cards. By introducing new hardware components, such as CAM/TCAM, the interface of the hardware components is called to implement flow table lookup extension instructions. By programming with Verilog during the design of smart network cards, the checksum instruction can be calculated. When defining the parameter interface of instructions in practice, one or more extension instructions with different parameters can be provided with the goal of facilitating software programming calls. Provide an instruction foundation for software defined networks.