dicex (Design of Integrated Circuits Examples)

Getting started with SPICE and verilog can be a daunting task. Companies that make integrated circuits spend millions on Electronic Design Automation (EDA) tools, and even then, the truth is, they are not great.

So, expecting open source EDA tools to be a polished, easy to use, easy to learn tools is too much to ask.

Luckliy, at the beginning of the integrated circuit journey we don't need the full blown commercial tools. At the beginning, we need to understand the principles of SPICE, Verilog, how to write the files, how to run the simulations, and how to view the results.

The difference between open source EDA tools and the commercial tools is that it's easier to make complex systems with the commercial tools, and believe me, ICs are very complex.

For now though, let's focus on the transistors, resistor, and the building blocks for digital circuits, the digital gates.

Getting started

• Install docker from docker.com
• Install git from git-scm.com
• Install TigerVNC from tigervnc.org

For a demo, see dicex and ciceda

Open a terminal (mac, linux) or powershell (windows).

Navigate to where you want your files.

On linux or mac

git clone https://github.com/wulffern/dicex
cd dicex

On windows

Multiple people have experienced problems running on windows. I would recommend starting ciceda from windows subsystem for linux instead

git clone https://github.com/wulffern/dicex --config core.autocrlf=input
cd dicex

On windows with windows subsystem for linux 2 (WSL2)

Download Ubuntu 20 LTS from app store. Start a Ubuntu shell

git clone https://github.com/wulffern/dicex
cd dicex

On mac

./ciceda_mac.sh

On windows

ciceda_windows.bat

On windows with WSL2

./ciceda_linux.sh

On linux

./ciceda_mac.sh

Start vncserver if you want GUI

./vncstart

You will be asked to enter a password the first time. The password is for the VNC server, and you can use whatever.

vncstart is a short shell script that starts a vncserver, it looks like this

$ cat vncstart
vncserver :0 -geometry 1920x1200

If the text in the VNC connection is too small, then change the geometry to fit your screen resolution (or the aspect ratio). You need to kill the vncserver if you want to start a new one with a different geometry.

vncserver -kill :0

Open TigerVNC, or on mac Finder -> Go -> Connect to server , connect to localhost:5900

If you're wondering how ciceda works, then look at https://github.com/wulffern/ciceda

SPICE

The folders called ex1 etc are related to the course TFE4152 Design of integrated circuits

There are a few examples in spice/, for example

cd sim/spice/NCHIO
make

Verilog

Examples for verilog are in ~/sim/verilog, for example

cd sim/verilog/

Start waveform viewer

gtkwave &

Run simulation

make

In GTKWave, File -> Open New Tab. Find counter/test.vcd

Support

I would try [email protected], however, I get about 100 emails per day, so my response rate is not great.