Independent Data-Integrity Verification for LLM-Driven Functional Coverage Closure in Hardware Design

Key points

• LLM agents can write directed tests that close functional coverage, but coverage only shows that a state was reached, not that the data on the way there was correct.1
• This is a long-known point in verification and we do not claim it as new.1
• On three architecturally distinct RTL designs (an asynchronous FIFO, a UART transmitter and an AHB2APB bridge) the agent raised coverage from 91.7%, 88.9% and 67.4% to 100% within its 8-iteration budget in every logged run, using one design-agnostic agent.1
• A reactive scoreboard monitor attached to the FIFO's base testbench also found a clock-domain-crossing bug in the author's own stimulus code.1

Sources (1)

• [1]Independent Data-Integrity Verification for LLM-Driven Functional Coverage Closure in Hardware Design
  arXiv (AI, ML, NLP, CV, robotics, multi-agent) · Oct 15, 09:24 AM

  We describe a small coverage-closure agent that applies it to an LLM loop: coverage is read from the report that the simulation itself exports (cocotb-coverage YAML) and never taken from the model's account, and data integrity is checked by scoreboards that are separate from the model.

  LLM agents can write directed tests that close functional coverage, but coverage only shows that a state was reached, not that the data on the way there was correct.

Extractive summary: sentences quoted from the sources.