Uniwa MIPS

This repository contains the implementation in VHDL of the microprocessor MIPS (Single-Cycle) for the course of Design of Digital Systems in University of West Attika. Both the MIPS implementation and testbench are available along with graphs of the microprocessor and ALU controller.

How to use

The VHDL code can be compiled using the Modelsim environment or Visual Studio Code. This section will guide you on how to setup Visual Studio Code for VHDL. For compiling VHDL the GHDL compiler is been used along with the GTKWave wave image program.

Windows

1. Download the GHDL compiler for windows here (Find the MINGW32.zip). Extract the root folder of the .zip file to your preferred location. Add the GHDL/bin in the PATH variable to access the compiler from the Windows Terminal.
2. In this tutorial the GTKWave program is used. Download GTKWave for Windows here. After download is completed unzip the file and place it at your preferred location. Add the gtkwave64/bin in the PATH variable to access GTKWave from the Windows Terminal.
3. Compile the .vhd files using:

    ghdl -a .\02_MIPS.vhd
    ghdl -a .\03_Testbench.vhd
    ghdl -r -fsynopsys testbench --wave="wave.ghw"

   After the compilation two files should have been created a .cf file and a wave.ghw file. The .cf is used during the ghdl -r and it can be removed if you want. The wave.ghw holds the wave of the testbench. You can open it using GTKWave like so: gtkwave wave.ghw.

Linux

1. In debian based distributions use:

   #Update package manager
   sudo apt update
    
   #Install dependencies
   sudo apt install build-essential gnat zlib1g-dev
   
   #Download the ghdl package
   sudo apt install ghdl
    
   #Download the gtkwave package
   sudo apt install gtkwave

   On other distros use the appropriate package manager.
2. Compile the .vhd files using the following commands:

   ghdl -a 02_MIPS.vhd
   ghdl -a 03_Testbench.vhd
   ghdl -r testbench --wave="wave.ghw"

   After the compilation a .cf and a wave.ghw should appear. The .cf file can be removed. You can open the waves of the testbench in the GTKWave using gtkwave wave.ghw

After you are done with the installations, open VS code on the directory that the .vhd files are located and compile from the integrated terminal. Dont forget to add a VHDL extension to VS Code to help with the VHDL coding.

GTKWave

This section will show you basic operations in the GTKWave program.

• You can add signals to the view by navigating in the SST tree view and selecting the object that contains the signal. Then in the panel below the tree view, select the target signal and "drag and drop" in the signals panel on the left.
• The signals inside the mips entity are located in the mipsmain object end.
• You can insert seperators, change the color of signals or the way that are presented by left clicking in the Signals section
• You can save as a .gtkw file in File->Write Save File As. This new file will hold any signals that you have added as well as seperators, colors or any other modifications and every time that the wave.ghw is updated, the .gtkw file will be updated as well.