Introduction

RIDECORE (RIsc-v Dynamic Execution CORE) is an Out-of-Order processor written in Verilog HDL. RIDECORE implements RISC-V, an open-source ISA that was originally designed by researchers at UC Berkeley (http://www.riscv.org).

RIDECORE's microarchitecture is based on "Modern Processor Design: Fundamentals of Superscalar Processors" (https://www.waveland.com/browse.php?t=624&r=d|259). Thus, we recommend users to read this book and our document (doc/ridecore_document.pdf) before using RIDECORE.

Our FPGA prototyping efforts have so far resulted in a prototype for Xilinx VC707 board. This prototype can operate at a clock frequency of 50MHz (Vivado 2015.2 is used for synthesizing and implementing the design).

Some of the hardware modules in RIDECORE are based on vscale (https://github.com/ucb-bar/vscale).

Toolchain Installation (Linux)

• riscv-tools
  riscv-tools include a C/C++ cross compiler for RISC-V and an ISA simulator. Please refer to the following URL for the installation guide: http://riscv.org/software-tools/

• iverilog
  iverilog is an open-source verilog simulator. To install iverilog in Ubuntu, run the following command:
  # apt-get install iverilog

• memgen
  memgen is an application generating binary code for RIDECORE from ELF files. The source code of memgen can be found in toolchain/memgen-v0.9. Run the make command to compile it.

Structure of this repository

The structure of this repository is described in doc/struct_repository.pdf.

How to use

• Compiling applications and generating binary code
  Some sample applications for RIDECORE can be found in src/test/ridecore/app. For each application, you can generate the binary code (init.bin) from the C code and the startup code (in Assembly) by using the make command. To use this binary code in verilog simulations, run "make copy" to copy it to src/test/ridecore/bin.

• Simulating RIDECORE
  The simulation code of RIDECORE can be found in src/test/ridecore/sim. You can generate an a.out executable file by running the make command. Currently, there are three options:

  • "make last" (testbench_last.v is compiled): generates an a.out executable file for executing applications without outputting any information about the states of RIDECORE during the execution.
  • "make dbg" (testbench.v is compiled): generates an a.out executable file which reports the states of RIDECORE in every clock cycle while executing applications.
  • "make pred" (testbench_pred.v is compiled): generates an a.out executable file which reports the branch prediction information while executing applications.