ATLAS: A Two-Level Layer-Aware Scheme for Routing with Cell Movement

Abstract

Placement and routing are two crucial steps in the physical design of integrated circuits (ICs). To close the gap between placement and routing, the routing with cell movement problem has attracted great attention recently. In this problem, a certain number of cells can be moved to new positions and the nets can be rerouted to improve the total wire length. In this work, we advance the study on this problem by proposing a two-level layer-aware scheme, named ATLAS. A coarse-level cluster-based cell movement is first performed to optimize via usage and provides a better starting point for the next fine-level single cell movement. To further encourage routing on the upper metal layers, we utilize a set of adjusted layer weights to increase the routing cost on lower layers. Experimental results on the ICCAD 2020 contest benchmarks show that ATLAS achieves much more wire length reduction compared with the state-of-the-art routing with cell movement engine. Furthermore, applied on the ICCAD 2021 contest benchmarks, ATLAS outperforms the first place team of the contest with much better solution quality while being 3× faster.