Open Source Core Design In FPGA Based On RISC-V

The chip is the center of all electronic devices,the processor is the control center of the chip,and the processor architecture is the most important part of the realization of the processor.Processor architecture,also known as instruction set architecture,is the communication bridge between the underlying chip and programming software.In recent years,the RISCV processor architecture has developed rapidly.Because of its advantages of open source,many domestic chip manufacturers are attracted.In order to better use it,the RISC-V instruction set architecture is analyzed and described in this paper.Based on the open source RISC-V Hummingbird E203 System on-Chip platform,a board level support package is realized,and a RISC-V software compilation environment is built under Windows operating system.The core of different types FPGA platform is achieved,and simple engineering based on RISC-V is developed based on the established software and hardware environment.Finally,the Hummingbird E203 core is extended.The following work is completed in this paper.RISC-V open source instruction set architecture is studied from non-privileged mode,privileged mode and external debugging mode in this paper.The characteristics and advantages of RISC-V instruction set architecture are analyzed.Referring to the Hummingbird Open Source Project,the framework,the design concept,the bus interface,the interrupt debugging method and the System on-Chip implementation are analyzed and studied.The board level support package based on the Hummingbird E200 series processor core is realized from the aspects of starter program and hardware driver,etc.Under the Windows operating system,a general development environment based on RISC-V core online programming and debugging is built.Based on the built software and hardware development environment,the RISC-V compiler tool chain and GCC compiler tool chain,the FPGA core hardware based on RISC-V and software development platform are tested and verified by using the domestic FPGA chip of Anlogic Company.Based on the built software and hardware development environment,the FPGA core hardware and software development platform based on RISC-V are achieved and proved by using FPGA chips of different platforms.On the basis of successful verification,a simple RISC-V software project is developed and researched.The Hummingbird E203 core is extended.The hardware design and physical implementation of SDRAM are realized,and the structure of ICB bus is analyzed.The IP of reading and writing SDRAM is added to the RISC-V based FPGA core by using ICB bus,so as to improve the functions of the hardware platform.The SDRAM module is added to the top BSP file.Finally,the added peripheral IP is verified and the RISC-V software engineering for controlling SDRAM is implemented.