Efficient decoupling capacitor planning via convex programming methods

Abstract

Achieving P/G supply signal integrity is crucial to success of nanometer VLSI designs. Existing P/G network optimization techniques are dominated by sensitivity based approaches. In this paper, we propose two novel convex programming based approaches for decoupling capacitor insertion in a P/G network, i.e., a semidefinite program and a linear program, which are global optimizations with theoretically guaranteed supply voltage degradation bounds. We also propose a scalability improvement scheme which enables us to apply the proposed convex programs to industry designs. We present a simple illustrative example and experimental results on an industry design, which show that the proposed semidefinite program guarantees supply voltage degradation bound for all possible supply current sources, while the proposed linear program achieves the most accurate supply voltage degradation control for a given set of supply current sources.