Scalable vectorless power grid current integrity verification

To deal with the growing phenomenon of electromigration (EM), power grid current integrity verification becomes indispensable to designing reliable power delivery networks (PDNs). Unlike previous works that focus on vectorless voltage integrity verification of power grids, in this work, for the first time we present a scalable vectorless power grid current integrity verification framework. By taking advantage of multilevel power grid verifications, large-scale power grid current integrity verification tasks can be achieved in a very efficient way. Additionally, a novel EM-aware geometric power grid reduction method is proposed to well preserve the similar geometric and electrical properties of the original grid on the coarse-level power grids, which allows to quickly identify the potential "hot wires" that may carry greater-than-desired currents in a given power grid design. The proposed multilevel power grid verification algorithm provides flexible tradeoffs between the current integrity verification cost and solution quality, while the desired upper/lower bounds for worst case currents flowing through a wire can also be computed efficiently. Extensive experimental results show that our current integrity verification approach can efficiently handle very large power grid designs with good solution quality.