Crosstalk minimization in four-layer non-Manhattan channel routing

It´s well known that a non-Manhattan channel router always uses no more tracks than a Manhattan channel router. For a bubble-sorting-based non-Manhattan channel, all of the nets can be routed by bubble-sorting swap passes in an optimal bubble-sorting solution, and these bubble-sorting swap passes can be further mapped onto track-to-track-routing processes in a 4-layer routing model. However, these proposed bubble-sorting-based non-Manhattan routers do not consider crosstalk or consider less, which has become a major issue in VLSI design due to the high frequency, long interconnecting lines and small spacing between interconnects in today´s integrated circuits. In this paper, we study the problem of crosstalk minimization in a bubble-sorting based non-Manhattan channel. A rerouting algorithm that combines segment-rerouting technique and layer reassignment is presented. This algorithm can decrease the wire length and modify the layout so that the crosstalk in the channel is minimized. Experimental results show that the proposed approach can reduce the crosstalk by an average of 27.9 % on a set of benchmark examples.