Structured Testbench Generation for LLM-Driven HDL Design and Verification-Oriented Data Curation

Problem: Automated testbench generation is a bottleneck in LLM-driven RTL workflows due to stochastic, costly, and low-coverage outputs from prompt-based methods. Method: STG (Structured Testbench Generation) exploits hardware design structure to produce deterministic testbenches. Finding: STG runs 720x faster than iterative LLM-based flows, achieves higher coverage, reduces false-pass verdicts, and is 11x faster and 127x more energy-efficient than LLM-based filtering on a single CPU core. Why it matters: STG enables rapid, reliable verification for LLM-driven design, improves RTL benchmarks by exposing faulty testbenches, and yields state-of-the-art distilled models with reduced node count.