In this paper, we present a hybrid placer, called NTUplace2, which integrates both the partitioning and the analytical (quadratic programming) placement techniques for large-scale mixed-size designs. Unlike most existing placers that minimize wirelength alone, we also control the cell density to optimize routability while minimizing the total wirelength. NTUplace2 consists of three major stages: multilevel global placement, legalization, and detailed placement. To handle mixed-size designs, in particular, we present a linear programming based legalization algorithm to remove overlaps between macros during global placement. Various other techniques are integrated to improve the solution quality at every stage.
展开▼
