Crosstalk Effect Analysis in VDSM Technologies

This paper presents the results of a detailed investigation of various crosstalk scenarios in VDSM technologies by using a distributed model of the crosstalk site while. As example of these results, it is stated that the combination of one crosstalk event at a site and another crosstalk event at a different site in the transitive fan-out of the first site may cause a slowdown or speedup of the circuit by an amount that can significantly exceed the sum of crosstalk effects caused by each site in isolation. As another example, it is reported that the common assumption that zero skew between the input transitions of aggressor and victim lines causes the worst case crosstalk effect is not always valid, and therefore, optimization or test based on such an assumption may be invalid. As importantly, this paper demonstrates the non-monotone behavior of the crosstalk effect with respect to the skew between the input transition of aggressor and victim lines. Our sensitivity analysis shows that the conventional assumptions, based on lumped modeling of crosstalk site, regarding the monotone behavior of crosstalk with respect to wire capacitance may be invalid. In contrast, it is legitimate to assume a monotone property for crosstalk with respect to the coupling capacitance and wire resistance and apply linear modeling with respect to those parameters. Finally the impact of our findings on driver sizing and side-load routing techniques are studied. For example, it is shown that increasing the size of the driver of an aggressor line may not necessarily increase the slowdown of the coupled lines as usually assumed by driver sizing algorithms.