Fast Circuit Simulation Techniques: Theory and Practice

Transient simulation is a critical step in the verification of integrated circuits. For this reason, much research in the area has concentrated on improving the efficiency of classical circuit simulation while maintaining acceptable accuracy. This paper presents simulation and device modeling techniques used in fast circuit simulation methods, particularly, Adaptively Controlled Explicit Simulation (ACES). ACES uses a combination of improved numerical integration methods, event driven circuit simulation, circuit partitioning, and piecewise linear device modeling to achieve two to three orders of magnitude speedup over classical circuit simulation methods. Fast circuit simulation techniques, due to use of circuit partitioning, event driven simulation and explicit integration are particularly amenable to parallelization. Theoretical and practical challenges of fast circuit simulation methods are summarized along with possible directions for future research.