An ECO algorithm for eliminating crosstalk violations

ECO changes are almost inevitable in late stages of a design process. Based on an existing design, incremental change is favored since it can avoid considerable efforts of re-doing the whole process and can minimize the disturbance on the existing converged design. In this paper, we address the CVE (Crosstalk Violation Elimination) problem. Due to the changes in a multiple layer routing design, the total capacitive crosstalk on some signal wire segments on a layer may be larger than their allowable bounds after post-layout timing/noise analysis. The target is to find a new routing solution without crosstalk violations under certain constraints which help to keep the new design close to the original one. We propose a two-stage algorithm to solve CVE problems, and present optimization strategies to speed up the execution. Experimental results demonstrate the efficiency and effectiveness of our algorithm.