A Faithful Binary Circuit Model

Abstract

Függer et al. (2016) proved that no existing digital circuit model, including those based on pure and inertial delay channels, faithfully captures glitch propagation: for the short-pulse filtration (SPF) problem similar to that of building a one-shot inertial delay, they showed that every member of the broad class of bounded single-history channels either contradicts the unsolvability of SPF in bounded time or the solvability of SPF in unbounded time in physical circuits. In this article, we propose binary circuit models based on novel involution channels that do not suffer from this deficiency. Namely, in sharp contrast to bounded single-history channels, SPF cannot be solved in bounded time with involution channels, whereas it is easy to provide an unbounded SPF implementation. Hence, binary-valued circuit models based on involution channels allow to solve SPF precisely when this is possible in physical circuits. Additionally, using both SPICE simulations and physical measurements of an inverter chain instrumented by high-speed analog amplifiers, we demonstrate that our model provides good modeling accuracy with respect to real circuits as well. Consequently, our involution channel model is not only a promising basis for sound formal verification but also allows to seamlessly improve existing dynamic timing analysis.