Engineering details of a stable force-directed placer

Ana/ytic placement methods that simultaneously minimize wire length and spread cells are receiving renewedattention from both academia and industiy In thispaper we describe the implementation details of a force-directed placer: FDP. Specifically, we provide (I) a description of eficient force computationfor spreading cells, (2) an illustrationofnumerical instability in these methods and a meam by which these instabilities are avoided, (3) spread metricsfor measuring cell distribution throughout theplacement region and (4) a complementary technique which aids in directly minimizing HPWL. Wepresent results comparing our ana/yticplacer to other academic toolsfor both standard cell and mixed-size designs. Compared to Kraftwerk and Capo 8.7, our tool produces results with an average improvement of 9% and 3%, respectively

• Type: Conference
• Year: 2004
• Where: ICCAD
• Authors: Kristofer Vorwerk, Andrew A. Kennings, Anthony Vannelli
• Keywords: Ana/ytic Placement Methods, Computationfor Spreading Cells, Force-directed Placer, Hardware, ICCAD 2004