Modeling crosstalk induced delay

The amplitude of coupled noise is often used in estimating the crosstalk effect. Coupling noise-induced delay measures the impact of crosstalk on circuit performance. Efficient computation of worst case noise-induced delays are essential, because such calculations are performed a huge number of times during timing analysis. In this paper we analyze the problem of crosstalk noise-induced delay in one logic stage. We observe that the popular method of crosstalk delay computation based on superposition of the victim´s switching waveform and the noise waveform determined when the victim is quiet, produces an underestimation of delay. To capture the crosstalk noise-induced delay, we introduce the concept of dynamic coupling noise waveform. We propose a method of synthesizing the dynamic noise waveform and using it to estimate the delay change.