Leveraging rule-based designs for automatic power domain partitioning

Leakage power reduction through power gating requires considerable design and verification effort. We present a scheme which uses high-level design description to automatically generate a collection of fine-grain power domains and associated control signals. We also describe a method of collecting the dynamic activity characteristics of a domain, viz. total inactivity and frequency of inactive-active transitions, which are necessary to decide the domain's suitability for power gating. Our automated power-gating technique provides power savings without exacerbating the verification problem because the power domains are correct by construction. We illustrate our technique using two wireless decoder designs.