Statistical estimation of delay-dependent switching activities inembedded CMOS combinational circuits

摘要

This paper describes a new procedure to estimate thendelay-dependent switching activities in CMOS combinational circuits. Thenprocedure is based on analytic and statistical approaches to takenadvantage of their time-efficiency over conventional event-drivennsimulation tools. For this study, combinational circuits driven byndiscrete-time logic signals are considered. By focusing on a specificnclass of combinational circuits, the transitional effects can benanalyzed more accurately by considering some of the delay effectsnneglected in previous studies, Also, to model the delay-dependentneffects, statistical properties such as the pattern probability, thenpropagation probability, and the distribution of the propagation delaynof switching activities are defined and evaluated. The simulationnresults on benchmark circuits indicate that the proposed procedurensignificantly speeds up the estimation process in comparison to thenconventional event-driven simulators. The reliability issues in thenaspect of switching activities are briefly discussed