Enhanced Verilog Support & Stability: GSoC 2025 Final Report

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Hello Everyone😊,

Welcome to my final blog for Google Summer of Code 2025 for the project Enhanced Verilog Support & Stability

What is the Project about🖥

Enhanced Verilog Support & Stability: The project works on the Verilog feature of CircuitVerse namely Circuit to Verilog and Verilog to Ciruit and its stability. The project works on taking the verilog feature to production, adding verilog modules for the circuit elements and removing bugs in the feature. The project also introduces new features like Verilog terminal, play/pause button to the simulator, improves the UI/UX of the verilog code-editor, updates the yosys repo, fixes bug ,implements full screen view for tools window and documents the verilog feature.

New features that have been added and merged include:

Verilog modules for circuit elements
Play/Pause button in the simulator
Improved UI/UX for code editor
Verilog terminal
Resizable & draggable view of tools window
Yosys Upgrade

Project link

Version confusion

CircuitVerse had implemented the versioning system to avoid merging big changes to the simulator directly. This resulted in the formation of V0/, V1/ and SRC/ folders in the vue-simulator. Currently the V0 folder is default source but it can be changed by altering the configuration files. My changes were made and merged into the V1/ folder. In future all these folders will be in sync and users can change between the verisons easily.

The Verilog feature in CircuitVerse includes

Circuit to Verilog - allows users to convert circuit to verilog code
Verilog to Circuit - allows users to convert verilog code to circuits

Adding the Verilog Modules for Circuit Elements

CircuitVerse can generate Verilog for circuits designed in the simulator. The moduleVerilog() function generates Verilog modules for circuit elements. Some elements (listed below) were missing these modules, causing calls to undefined Verilog functions. The first week focused on adding the missing Verilog modules.

The Verilog Module for the following Circuit elements were added:

SR Flip Flops
JK Flip Flops
ALU
D-Latch
ForceGate
LSB
MSB
TestBench element

Checkout the Below Video for before and after fix

In total 8 verilog modules were added, some of them are displayed below :

Circuit to Verilog

Bugs which were fixed in the Verilog Modules

Wrong and incomplete verilog code for adder , the adder

adder

Undefined parameters in the Flip Flops
Missing bitwidth support in some elements
Inconsistent verilog logic
SR flip flop wrong logic

Yosys upgrade and migration

Yosysdigitaljs-server created by Marek Materzok is the technology behind the feature that allows users to convert Verilog code into circuits in the simulator.

Yosys feature

The Circuitverse Yosys forked repo is behind its parent by some 39 PRs, the parent repo had been migrated from js to ts and even the folder structure has been changed.These changes include the server file to receive the request from circuitverse backend, docker file and other configuartion and minor changes from CircuitVerse.

Verilog to circuit feature

The Yosys repo is now updated, folder structure updated & consistent with its parent and migrated to ts. In the future any changes to its parent can be easily merged with much conflicts between the two.

Revamping the Verilog code editor and Verilog Terminal

CircuitVerse provides its users the feature of Verilog code editor. Which can be used by the users to write verilog code and then convert them into circuits and further integrate them into their circuits on the simulator.

The goal of the Code Editor is to:

The Code Editor enables users to write and edit Verilog code directly inside CircuitVerse. The users can write and edit their verilog code inside the code editor. Once the code is written, it can be sent to backend powered by Yosys, an open-source synthesis tool. The Yosys backend processes the code, parses the output, and automatically generates a visual circuit based on the Verilog description. This ciruit then turns into a black box circuit that can be simulated in the circuitverse simulator and also connected with other circuit elements.

The Code Editor is built using CodeMirror - a powerful and customizable browser-based code editor.

The code Editor has the following features currently:

Syntax highlighting for Verilog
Smart indentation
Line numbering
Theme customization (Solarized, Monokai, Blackboard, and more)
Reset editor button

But the UI/UX of the code editor is not particularly encouraging for the users, also there are lots of features that can be added to it to make it better.

Verilog to circuit feature

I have implemented the following things, which were proposed:

Improved indentation between code and line numbering, between numbering and the edge
CTRL + S shortcut for the save button
Option to increase the font size
Displaying error message properly, maybe a whole terminal experience to display the error message
Dark default theme in Vue-Simulator
Code completion
Code folding and bracket matching

Verilog Terminal

After the initial changes of font, line-spacing, padding, and auto-bracket matching were implemented to the verilog code editor, there was a need to further improve the verilog code editor and align it with traditional code editors. To do this Verilog code editor terminal was introduced.

The Verilog Terminal provides a console-like view for synthesis/log outputs and errors, reducing context switching. It complements the play/pause control so users can pause simulation, inspect messages, and iterate efficiently.

The verilog terminal logs the process status, success messages, and error logs. It also displays the synatx and other error messages sent from the YOSYS server and displays it to the users, so that they can debug their Verilog Code easily. Further Enhancements can also be added to it, which can include terminal taking commands to save, reset and close the verilog editor and further enhancements.

Verilog Terminal

Play/Pause Button to the Simulator

The play/pause button halts the simulation engine, clocks, and UI updates. Users can pause to build/debug circuits and conserve browser resources, then resume when ready. This reduces confusion and supports workflows like debugging, testbenches, and timing diagrams.

Play pause button

Resizable & draggable view of tools window

The tools section of the Simulator contains various tools, each having thier own window. In the vue-simulator the windows of the tools are neither resizable and nor draggale which causes a lot fo trouble for the users, as they can neither change the size or drag it somewhere. These tools windows were made resizable and draggable allowing the users to do the both.

Verilog feature documentation

As part of this project, I documented the Verilog feature in detail with examples for CircuitVerse users.

I also created developer-focused docs to make it easy to set up the Verilog feature locally and extend it further.

Documenting the Verilog features:

doc1 doc2 doc3

Pull Requests

Learning

This project taught me a lot about VueJs and how the simulation engine works behind the scenes. I got hands-on with Verilog, writing modules and testbenches, and really improved my digital design skills. Working with Yosys and its move to TypeScript was a great way to learn about backend integration and modern codebases.

I also picked up better object-oriented coding habits and got much faster at debugging tricky issues. Setting up Docker and container networking was new for me, but now I feel confident managing development environments. Overall, I became a more versatile coder and learned a ton from collaborating with the CircuitVerse community.

Conclusion

My journey so far has been exciting and amazing. Each week I stumble upon things I don’t know, and I learn it, exeriment with it and then implement it. It has truly been a developers dream till now. My mentors and CircuitVerse community have been very helpful and inspirational in my little journey. Looking forward to contribute and learn more.

I would like to thank, Aboobacker MK, Vedant Jain, Niladri Adhikary, Josh Varga, Aman Asrani, and other mentors and circuitverse contributors for helping and mentoring me throught the journey.