AssertLLM: Generating and Evaluating Hardware Verification Assertions from Design Specifications via Multi-LLMs

Assertion-based verification (ABV) is a critical method for ensuring design circuits comply with their architectural specifications, which are typically described in natural language. This process often requires significant interpretation by engineers to convert these specifications into functional verification assertions. Existing methods for generating assertions from natural language specifications are limited to sentences extracted by engineers, discouraging the practical application. In this work, we present AssertLLM, an automatic assertion generation framework for complete specification files. AssertLLM breaks down the complex task into three phases, incorporating three customized LLMs for extracting structural specifications, mapping signal definitions, and generating assertions. Additionally, we provide an open-source benchmark for assessing assertion generation capabilities. Our evaluation of AssertLLM on a full design, encompassing 23 signals, demonstrates that 89% of the generated assertions are both syntactically and functionally accurate.