Accurate Estimation of Dynamic Timing Slacks using Event-Driven Simulation

Abstract

The pessimistic nature of conventional static timing analysis has turned the attention of many studies to the exploitation of the dynamic data-dependent excitation of paths. Such studies may have revealed extensive dynamic timing slacks (DTS), however, they rely on frameworks that inherently make worst-case assumptions and still ignore some data-dependent timing properties. This may cause significant DTS underestimation, leading to unexploited frequency scaling margins and incorrect timing failure estimation. In this paper, we develop a framework based on event-driven timing simulation that identifies the underestimated DTS, and evaluate its gains on various post-place-and-route designs. Experimental results show that our event-driven simulation scheme achieves on average 2.35% and up-to 194.51% DTS improvement over conventional graph-based techniques. When compared to existing frequency scaling schemes, the proposed approach enables us to further increase the clock frequency by up-to 10.42%. We also demonstrate that our approach can reveal that timing failures may be up-to $\mathbf{2.94}\times$ less than the ones estimated by existing failure estimation techniques, under potential variation-induced delay increase.