# VFocus: Better Verilog Generation from Large Language Model via Focused Reasoning

arXiv: https://arxiv.org/abs/2511.02285 · HTML: https://mlsanity.com/paper/2511.02285/

## Key facts

- Cited by 4 papers in the map (data through 14 Oct 2026).
- Placed in Reasoning for agents, planning and code, one of 17 directions in LLM reasoning.
- Builds on 10 of its 20 references that are in the map.
- First posted on arXiv 4 Nov 2025.

## Placed in

- LLM reasoning / [Reasoning for agents, planning and code](https://mlsanity.com/lr/reasoning-for-agents-planning-and-code/)

## Builds on (most cited first, 10 of 10)

- [Evaluating Large Language Models Trained on Code](https://mlsanity.com/paper/2107.03374/) (2021)
- [DeepSeek-R1: Incentivizing Reasoning Capability in LLMs via Reinforcement Learning](https://mlsanity.com/paper/2501.12948/) (2025)
- [OpenAI o1 System Card](https://mlsanity.com/paper/2412.16720/) (2024)
- [From System 1 to System 2: A Survey of Reasoning Large Language Models](https://mlsanity.com/paper/2502.17419/) (2025)
- [Thoughts Are All Over the Place: On the Underthinking of o1-Like LLMs](https://mlsanity.com/paper/2501.18585/) (2025)
- [VerilogCoder: Autonomous Verilog Coding Agents with Graph-based Planning and Abstract Syntax Tree (AST)-based Waveform Tracing Tool](https://mlsanity.com/paper/2408.08927/) (2024)
- [A Survey of Research in Large Language Models for Electronic Design Automation](https://mlsanity.com/paper/2501.09655/) (2025)
- [CodeV: Empowering LLMs with HDL Generation through Multi-Level Summarization](https://mlsanity.com/paper/2407.10424/) (2024)
- [MAGE: A Multi-Agent Engine for Automated RTL Code Generation](https://mlsanity.com/paper/2412.07822/) (2024)
- [CorrectBench: Automatic Testbench Generation with Functional Self-Correction using LLMs for HDL Design](https://mlsanity.com/paper/2411.08510/) (2024)

## Built on by (most cited first, 4 of 4)

- [CorrectHDL: Agentic HDL Design with LLMs Leveraging High-Level Synthesis as Reference](https://mlsanity.com/paper/2511.16395/) (2025)
- [VeriPilot: An LLM-Powered Verilog Debugging Framework](https://mlsanity.com/paper/2606.23759/) (2026)
- [LLMs in Digital EDA: A perspective on shifting roles from Generation to Orchestration](https://mlsanity.com/paper/2608.27184/) (2026)
- [LLM for EDA in Front-End Design: Challenges and Opportunities](https://mlsanity.com/paper/2607.09616/) (2026)

## Abstract (arXiv)

Large Language Models (LLMs) have shown impressive potential in generating Verilog codes, but ensuring functional correctness remains a challenge. Existing approaches often rely on self-consistency or simulation feedback to select the best candidate, but they miss opportunities to focus LLM reasoning on the most informative parts of the design. We propose VFocus, a three-stage framework that enhances Verilog generation by sharpening the focus of LLM reasoning onto critical decision points in the code generation process. In the pre-ranking stage, VFocus generates multiple code candidates through LLM prompting, retries for syntactically valid outputs, and introduces a textitDensity-guided Filtering to retain candidates that fall within the "reasoning sweet spot" for functional correctness. In the ranking stage, we simulate each code candidate using an automatically generated testbench and apply self-consistency-based clustering to identify the most consistent outputs. Finally, in the post-ranking refinement stage, VFocus performs inconsistency mining on top-ranked candidates and invokes reasoning-augmented LLM prompts for candidate refinement. Experiments on the VerilogEval-Human benchmark show that VFocus significantly improves the pass@1 correctness across multiple reasoning LLMs, demonstrating its effectiveness in enhancing Verilog generation for complex hardware design tasks.