Closing the Gap between Global and Detailed Placement

Improving routability during both global and detailed routing stage has become a critical problem in modern VLSI design. In this work, we propose a placement framework that offers a complete coverage solution in considering both global and detailed routing congestion. A placement migration strategy is proposed, which improves detailed routing congestion while preserving the placement integrity that is optimized for global routability. Using the benchmarks released from ISPD2014 Contest, practical design rules in advanced node design are considered in our placement framework. Evaluation on routability of our placement framework is conducted using commercial router provided by the 2014 ISPD Contest organizers. Experimental results show that the proposed methodologies can effectively improve placement solutions for both global and detailed router.