Multi-Level Timing Simulation on GPUs

Timing-accurate simulation of circuits is an important task in design validation of modern nano-scale CMOS circuits. With shrinking technology nodes, detailed simulation models down to transistor level have to be considered. While conventional simulation at logic level lacks the ability to accurately model timing behavior for complex cells, more accurate simulation at lower abstraction levels becomes computationally expensive for larger designs. This work presents the first parallel multi-level waveform-accurate timing simulation approach on graphics processing units (GPUs). The simulation uses logic and switch level abstraction concurrently, thus allowing to combine their advantages by trading off speed and accuracy. The abstraction can be lowered in arbitrary regions of interest to locally increase the accuracy. Waveform transformations allow for transparent switching between the abstraction levels. With the utilization of GPUs and thoughtful unification of algorithms and data structures, a fast and versatile high-throughput multi-level simulation is obtained that is scalable for millions of cells while achieving runtime savings of up to 89% compared to full simulation at switch level.