Timing-driven placement based on partitioning with dynamic cut-net control

Abstract

This paper presents a partitioning-based, timing-driven placementalgorithm. The partitioning step itself is timing-driven and basedon solving a quadratic programming problem iteratively. Theplacement algorithm does not rely on interleaved timingcalculations, which tend to be inaccurate. Instead, it achieves thedesired result by controlling the number of times that a path inthe circuit can be cut. In addition to the cutting constraint, apre-locking mechanism and timing-aware terminal propagation aredeveloped and integrated into the flow. The detailed placement stepis formulated as a constrained quadratic program and solvedefficiently. Results show improvements of 23.41% on averagecompared to another timingdriven placement system Timing-QUAD andsignificant improvements over Eisenmanns placement algorithm.