Modeling and optimizing differential signaling for reducing crosstalk noise

Minimizing crosstalk is a major concern in high-speed differential buses design. The power/ground pins are distributed uniformly and the performance of a bus is usually gated by the performance of the worst differential signal in the bus. In this paper, we propose a fast algorithm to generate nearly uniform power/ground distributions by applying force-directed optimization. With each power/ground distribution, our linear perturbation algorithm enumerates the differential signal pairing combinations. The algorithm is further sped up significantly by our branch-and-bound scheme and max information gain signal selection. These differential signal assignments are then assessed by applying a benchmark parameter that describes the relative performance of each assignment. Experimental results demonstrate the high efficiency and significant electrical benefit of our algorithm.