Universal Methodology to Handle Differential Pairs during Pin Assignment

Differential signaling has been a major challenge in design automation. The routing of differential pairs requires a suitable pin assignment of the respective nets. However, current automatic pin assignment algorithms lack the ability to consider differential pairs. We present a methodology to include differential pairs during pin assignment. Our solution can be applied to automatic or manual pin assignment processes without changing the methodologies already in place. This universality is achieved by using any established pin assignment approach as a black box, which is extended by pre and post processing steps. Extensive studies in industrial design flows show that our differential pair methodology does not compromise pin assignment quality with the added benefit of effective differential pair allocations. IBM Research and Development, Böblingen, Germany