Analytic Models for Crosstalk Delay and Pulse Analysis Under Non-Ideal Inputs

In this paper we develop a general methodology to analyze crosstalk to obtain insight into effects that are likely to cause errors in deep submicron high speed circuits. We focus on crosstalk due to capacitive coupling between a pair of lines. We first consider the case where crosstalk noise manifests as a pulse and characterize the maximum amplitude, width, energy and timing of this pulse. Closed form equations quantifying the dependence of these pulse attributes on the values of circuit parameters and the rise time of the input transition are derived. We also consider how crosstalk causes slowdown (speedup), i.e. increases (decreases) the rise/fall times of signals on coupled lines, when their inputs have transitions in the opposite (same) directions. Expressions relating the slowdown (speedup) to circuit parameters, the rise/fall times of the input transitions, and the skew between the transitions are derived. We show that crosstalk effects can be significantly aggravated by variations in the fabrication process. New design corners are identified for validation of designs that have significant crosstalk effects. Finally, the results of our analysis provide conditions that must be satisfied by a sequence of vectors used for validation of designs as well as post-manufacturing testing of devices in the presence of significant crosstalk.