Interconnect performance corners considering crosstalk noise

Abstract

Process induced variations in the interconnect capacitance and resistance have resulted in significant uncertainly in the interconnect delay. In this work, we propose a new method to compute the interconnect corner considering coupling-noise due to simultaneous switching of aggressors. In prior approaches, the interconnect corners were computed under the assumption that the aggressor nets are not switching and no coupling-noise is injected on the victim net. In this paper, we first show that the interconnect corners obtained under such assumptions could in reality be much different from the true interconnect corner and could therefore result in optimistic delay analysis, particularly for fast-path analysis performed to check hold time violations. We also show that in some cases, the interconnect corner may not lie at an extreme point of the process variation range. In this work, we use the Elmore delay metric to efficiently search for the correct interconnect corner of the victim stage considering delay noise. We then show experimental results to verify the effectiveness of our proposed approach and demonstrate that the traditional approaches of computing the interconnect corners could lead to errors of up to 60% on a net by net basis.