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GPGPU processor core, implemented in SystemVerilog.
C C++ SystemVerilog Other
branch: master

Nyuzi Processor

Nyuzi is an experimental multicore GPGPU processor. It supports vector floating point, hardware multithreading, and cache coherence. The SystemVerilog hardware design is synthesizable and runs on FPGA. This project also includes a LLVM-based C++ toolchain, a symbolic debugger, an emulator, software libraries, and hardware verification tests. It is useful as a platform for microarchitecture experimentation, performance modeling, and parallel software development.

License: Apache 2.0
Mailing list:!forum/nyuzi-processor-dev

Getting Started

These instructions explain how to get the design working in Verilog simulation. This environment allows cycle-accurate modeling of the hardware without an FPGA.

Required Software

The following sections explain how to install these packages.

Optional Software:

Building on Linux

First, build the Nyuzi toolchain following instructions in

Next, you will need Verilator. Many package managers have Verilator, but it may be out of date. It can be installed as follows (assuming Ubuntu):

sudo apt-get install verilator
verilator --version.

Bug fixes in at least version 3.864 are necessary for it to run properly (some of the bugs are subtle, so it may appear to work at first but then fail in odd ways if you are out of date). If you don't have a recent version, build from source using these instructions:

On Linux, you can install the remaining dependencies using the built-in package manager (apt-get, yum, etc). I've only tested this on Ubuntu, for which the instructions are below. You may need to tweak the package names for other distros:

sudo apt-get install gcc g++ python perl emacs openjdk-7-jdk gtkwave imagemagick libsdl2-dev

git clone
cd NyuziProcessor
make test

To run 3D renderer (in emulator)

cd software/apps/sceneview
make run

Building on MacOS

On Mavericks and later, the command line compiler can be installed by typing

xcode-select --install 

It will also be installed automatically if you download XCode from the Mac App Store.

Build the Nyuzi toolchain following instructions in

You will need to build Verilator from source using instructions here:

MacOS has many of the required packages by default, the exceptions being Imagemagick and SDL. To install the remaining packages, I would recommend a package manager like MacPorts. The command line for that would be:

sudo port install imagemagick libsdl2

git clone
cd NyuziProcessor
make test

To run 3D renderer (in emulator)

cd software/sceneview
make run

Building on Windows

I have not tested this on Windows. Many of the libraries are already cross platform, so it should theoretically be possible.

Running on FPGA

This currently only works under Linux. It uses Terasic's DE2-115 evaluation board. In addition to the packages listed above, this also requires Quartus II FPGA design software.


  1. This loads programs onto the board over the serial port, so your development machine must be connected to the FPGA board using a serial cable.

  2. The environment variable SERIAL_PORT must be set to the path to the serial device. For a Prolific USB based dongle, for example, the path is.

    export SERIAL_PORT="/dev/ttyUSB0"

    For a different serial device, you will need to figure out the device path.

  3. Ensure you can access the serial port without being root:

    sudo usermod -a -G dialout $USER
  4. Make sure the FPGA board is in JTAG mode by setting SW19 to 'RUN'

On some distributions of Linux, the Altera tools have trouble talking to USB if not run as root. This can be remedied by creating a file /etc/udev/rules.d/99-custom.rules and adding the following line:

ATTRS{idVendor}=="09fb" , MODE="0660" , GROUP="plugdev" 


The build system is command line based and does not use the Quartus GUI.

  1. Synthesize the design (ensure quartus binary directory is in your PATH, by default installed in ~/altera/[version]/quartus/bin/)

    cd rtl/fpga/de2-115
  2. Load the configuration bitstream onto the FPGA.

    make program 
  3. Press key 0 on the lower right hand of the board to reset the processor

  4. Load program into memory and execute it using the runit script as below.

    cd ../../../tests/fpga/blinky

Programs can be reloaded by repeating steps 3 & 4. The bitstream does not need to be reloaded as long as the board is powered (it will be lost if it is turned off, however).

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