A figure of merit for assertions in verification.

Assertion quality is critical to the confidence and claims in a design's verification. In current practice, there is no metric to evaluate assertions. We introduce a methodology to rank register transfer level (RTL) assertions. We define assertion importance and assertion complexity and present efficient algorithms to compute them. Our method ranks each assertion according to its importance and complexity. We demonstrate the effectiveness of our ranking for pre-silicon verification on a detailed case study. For completeness, we study the relevance of our highly ranked assertions in a post-silicon validation context, using traced and restored signal values from the design's netlist.