Density Aware Detailed Placement and Legalization Considering Displacement Constraint

• Main Authors: Tsai, Chih-Wei, 蔡至韋
• Other Authors: Mak, Wai-Kei
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/83040368380754344769

碩士 === 國立清華大學 === 資訊工程學系 === 102 === Placement is one of the important steps in physical design. Modern placement process involves global placement, legalization, detailed placement. Global placement generate a placement solution with optimized objectives such as wire-length, routability, timing. Legalization removes cells overlap and makes sure the cells on the placement site. Detailed placement (DP) relocates cells to obtain a better placement solution. Since objectives are optimized in global placement, legalization and detailed placement should not only optimized its objective, but also preserved the global placement solution quality. In this thesis, we proposed a two-stage detailed placement algorithm for minimizing wire-length, also can preserve the global placement solution quality by constraining the cell displacement. In the first stage, we can effectively eliminate the penalty caused by high cell density. In the second stage, we further reduce wire-length without increasing the penalty. In experiments, we use ICCAD 2013 detailed placement contest [3] benchmarks, the result shows we could improve the global placement results 12.36% - 15.15% on average under different displacement constraint and target placement density.