Unified quadratic programming approach for mixed mode placement

摘要

A complete placement system, UPlace, for mixed mode designs is presented, which consists of a force-directed global placement, and a zone-refinement based detailed placement. For global placement, a unified objective function capturing both wire length and cell distribution is proposed; quadratic programming is formulated to optimize the unified object function efficiently; a discrete cosine transformation method is devised to calculate the uneven cell distribution cost. A dynamic approach for decomposing multi-pin nets into two-pin nets is also introduced for better wire length modeling. Zone refinement method is used for a unified legalization and detailed placement process. Experimental results show that the placement algorithm is very promising.