RVCore Project

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RVCore Project, Arch Lab, Tokyo Tech

The RVCore Project is a research and development project of the RISC-V soft processor highly optimized for FPGAs.

RVCoreP (RISC-V Core Pipelined version) is one of the RISC-V soft processor cores of the RVCore Project. It is an optimized RISC-V soft processor of five-stage pipelining.

What's new

  • 2020/05/18 : Add the page how to build the RISC-V cross compiler and RISC-V binary files
  • 2020/05/17 : Change of web page structure and release of Ver.0.5.1
  • 2020/05/03 : Added the setting method about New-line code
  • 2020/03/04 : This page is released about Ver.0.4.6 !

About RVCoreP

The main specifications of RVCoreP are shown below:

  • An optimized RISC-V soft processor
  • Adopt RV32I of RISC-V as an instruction set architecture, which is the basic 32-bit integer instruction set
  • Adopt five-stage pipelining
    • Instruction fetch (If)
    • Instruction decode (Id)
    • Instruction execution (Ex)
    • Memory access (Ma)
    • Write back (Wb)
  • Apply three effective optimization methods to improve the operating frequency
    • Instruction fetch unit optimization including the pipelined branch prediction mechanism
    • ALU optimization
    • Data alignment and sign-extension optimization for data memory output
  • Implemented in Verilog HDL
  • Run RISC-V programs compiled with RV32I
    • By Verilog HDL simulation using Verilator or Icarus Verilog
    • On the FPGA boards including Xilinx Artix-7 FPGA

Download source file

The latest version of RVCoreP is Ver.0.5.1: rvcorep_ver051.zip

The other old version is as follows:

This source code is released under the MIT License, see LICENSE.txt.

–

> Change log #^

  • Ver.0.5.1 : The version supporting Verilator, Embench, pySerial, Vivado 2019.2
  • Ver.0.4.6 : The version used in our submitted manuscript

<

–

–

> Install command #

Install verilator by the following command. 

$ sudo apt install verilator

Install iverilog by the following command. 

$ sudo apt install iverilog

Install pySerial by the following command. 

$ pip3 install pyserial

←-

Getting started guide

(1) Download the source code of the RVCoreP 

$ wget http://www.arch.cs.titech.ac.jp/wk/rvcore/lib/exe/fetch.php?media=rvcorep_ver051.zip -O rvcorep_ver051.zip

(2) Extract the downloaded zip file 

$ unzip rvcorep_ver051.zip
$ cd rvcorep_ver051

–

> Verilog HDL simulation using Verilator #

You execute the following commands on the recommended environment.

(1) Compile source code written in Verilog HDL using Verilator 

$ make
verilator -DSERIAL_WCNT=2 -DNO_IP --public --top-module top --clk CLK --x-assign 0 --x-initial 0 --no-threads -O2 -Wno-WIDTH -Wno-UNSIGNED --exe sim.cpp --cc top.v main.v uart.v debug.v proc.v
make -j -C obj_dir -f Vtop.mk Vtop
cp obj_dir/Vtop simv

The executable file simv is generated after the compilation is performed.

(2) Execute the Verilog HDL simulation

By default, the test benchmark is executed. The memory file of the test benchmark is test.mem.

–

> Execution result when running `test.mem` #

$ make run ./simv Run test.mem Initializing : .......... -------------------------------------------------- ---- nqueen ---- Nqueen : N = 6 The number of solutions = 4 ---------------- ---- qsort ---- Sorted Seqence : 59321 A4C86 AC7D3 B210A 142044 1DEC15 1EC216 2536B2 278BCF 34A2AC ---------------- ---- fib ---- Fibonacci Seqence : 1: 1 2: 1 3: 2 4: 3 5: 5 6: 8 7: D 8: 15 9: 22 A: 37 ---------------- ---- acker ---- acker(0,0) = 1 acker(0,1) = 2 acker(0,2) = 3 acker(1,0) = 2 acker(1,1) = 3 acker(1,2) = 4 acker(2,0) = 3 acker(2,1) = 5 acker(2,2) = 7 ---------------- == elapsed clock cycles : 35030 == valid instructions executed : 28934 == IPC : 0.825 == branch prediction hit : 3615 == branch prediction miss : 1430 == branch prediction total : 5045 == branch prediction hit rate : 0.716 == the num of load-use stall : 1897 == estimated clock cycles : 35121 == r_cnt : 000088d6 == r_rout : 000000a0 - top.v:150: Verilog $finish

You will see the above output. The information such as IPC (Instructions Per Cycle) and branch prediction hit rate is output to the console after running simulation.

←-

(3) Execute the Dhrystone and Coremark benchmarks by the Verilog HDL simulation

You compile and execute with Dhrystone and Coremark benchmarks.

The memory files, the binary files, and the dump files are stored in the bench/ directory.

For Dhrystone, three configurations are prepared by the parameter NUMBER_OF_RUNS.

For Coremark, three configurations are also prepared by the parameter ITERATIONS.

These benchmarks can be run with the following commands. 

$ make [configuration name]
$ make run

(4) Execute the Embench benchmark by the Verilog HDL simulation

You compile and execute with 19 benchmarks in Embench.

The memory files, the binary files, and the dump files are stored in the embench/ directory.

These benchmarks can be run with the following commands. 

$ make [benchmark name]
$ make run

The execution results of dhrystone3, coremark3, and 19 benchmarks of Embench are summarized in the file result.txt.

←-

–

> Implementation and execution on the Nexys 4 DDR board #

You execute the following process in the directory of the downloaded source code on the recommended environment.

(1) Open the project file main.xpr in Xilinx Vivado 

$ vivado main.xpr &

(2) Perform logic synthesis, placement and routing, and generating bitstream using Xilinx Vivado

By default, the operating frequency of the processor is set to 160MHz.

(3) Write the generated bitstream to the FPGA board

When the bitstream data is correctly written to the FPGA board, the DONE LED lights up and “00000000” is displayed on the 8-digit 7-segment LEDs.

(4) Prepare for 8M baud serial communication

For serial communication with RVCoreP, the pySerial program serial_rvcorep.py is used.

This program sends a binary file to the FPGA board and outputs the received characters via pySerial.

Before executing this program, check the setting of the port used for serial communication in the program.

By default, /dev/ttyUSB1 is set.

The usage of this program is as follows: 

$ python3 serial_rvcorep.py [serial baud rate (Mbaud)] [binary file name]

(5) Send the RISC-V program binary to the FPGA board by serial communication and execute the program

To send the test program test.bin and start serial communication, execute one of the following commands. 

$ python3 serial_rvcorep.py 8 "test.bin"

or 

$ python3 serial_rvcorep.py

The following execution result is output via serial communication.

–

> Execution result when running `test.bin` #

$ python3 serial_rvcorep.py serial baud rate : 8000000 send file : test.bin ---- nqueen ---- Nqueen : N = 6 The number of solutions = 4 ---------------- ---- qsort ---- Sorted Seqence : 59321 A4C86 AC7D3 B210A 142044 1DEC15 1EC216 2536B2 278BCF 34A2AC ---------------- ---- fib ---- Fibonacci Seqence : 1: 1 2: 1 3: 2 4: 3 5: 5 6: 8 7: D 8: 15 9: 22 A: 37 ---------------- ---- acker ---- acker(0,0) = 1 acker(0,1) = 2 acker(0,2) = 3 acker(1,0) = 2 acker(1,1) = 3 acker(1,2) = 4 acker(2,0) = 3 acker(2,1) = 5 acker(2,2) = 7 ----------------

The 7-segment LED shows the value of the program counter of the processor at the end of execution. If you execute the test benchmark test/test.bin, the output to the 7-segment LEDs is 000000A0.

When the button “BTNU” is pressed, the 7-segment LED shows the number of execution cycles. If you execute the test benchmark test/test.bin, the output　to the 7-segment LEDs is 000088D6.

←-

This program is terminated by Ctrl-C.

If you want to send the binary file of the program to the FPGA board again and execute it, proceed from step (3).

←-

How to build the RISC-V cross compiler and RISC-V binary files that works with RVCoreP

Please refer the fllowing page: How to build the RISC-V cross compiler and RISC-V binary files that works with RVCoreP

Publication

This processor RVCoreP is explicated in a preprint paper of arXiv.

Hiromu Miyazaki, Takuto Kanamori, Md Ashraful Islam, Kenji Kise: RVCoreP : An optimized RISC-V soft processor of five-stage pipelining, arXiv:2002.03568 [cs.AR] (2020-02-10).

This paper is submitted to the Institute of Electronics, Information and Communication Engineers (IEICE).

Contact

Kise Laboratory, Department of Computer Science, School of Computing, Tokyo Institute of Technology (Tokyo Tech)

E-mail: miyazaki (at) arch.cs.titech.ac.jp

Other Project

Copyright © 2020 Kise Laboratory, Tokyo Institute of Technology

old1.1727010379.txt.gz · Last modified: 2024/09/22 22:06 by kise