From Concept to Practice: an Automated LLM-aided UVM Machine for RTL Verification

Verification presents a major bottleneck in Integrated Circuit (IC) development, consuming nearly 70% of the total development effort. While the Universal Verification Methodology (UVM) is widely used in industry to improve verification efficiency through structured and reusable testbenches, constructing these testbenches and generating sufficient stimuli remain challenging. These challenges arise from the considerable manual coding effort required, repetitive manual execution of multiple EDA tools, and the need for in-depth domain expertise to navigate complex designs. Here, we present UVM², an automated verification framework that leverages Large Language Models (LLMs) to generate UVM testbenches and iteratively refine them using coverage feedback, significantly reducing manual effort while maintaining rigorous verification standards. To evaluate UVM², we introduce a benchmark suite comprising Register Transfer Level (RTL) designs of up to 1.6K lines of code. The results show that UVM² reduces testbench setup time by up to 38.82× compared to experienced engineers, and achieve average code and function coverage of 87.44% and 89.58%, outperforming state- of-the-art solutions by 20.96% and 23.51%, respectively. © 2025 IEEE.