The Involution Tool for Accurate Digital Timingand Power Analysis

Abstract

We introduce the prototype of a digital timing simulation and power analysis tool for integrated circuit (Involution Tool) which employs the involution delay model introduced by Fugger et al. at DATE’15. Unlike the pure and inertial delay¨ models typically used in digital timing analysis tools, the involution model faithfully captures pulse propagation. The presented tool is able to quantify for the first time the accuracy of the latter by facilitating comparisons of its timing and power predictions with both SPICE-generated results and results achieved by standard timing analysis tools. It is easily customizable, both w.r.t. different instances of the involution model and different circuits, and supports automatic test case generation, including parameter sweeping. We demonstrate its capabilities by providing timing and power analysis results for three circuits in varying technologies: an inverter tree, the clock tree of an open-source processor, and a combinational circuit that involves multi-input NAND gates. It turns out that the timing and power predictions of two natural types of involution models are significantly better than the predictions obtained by standard digital simulations for the inverter tree and the clock tree. For the NAND circuit, the performance is comparable but not significantly better. Our simulations thus confirm the benefits of the involution model, but also demonstrate shortcomings for multi-input gates.