A PLACEMENT FLOW FOR VERY LARGE-SCALE MIXED-SIZE CIRCUIT PLACEMENT

Abstract

The very large-scale integrated circuit (VLSI) placement problem is to determine the exact location of each movable circuit element within a given region. It is a crucial process in physical design, since it affects performance, power consumption, routability, and heat distribution of a design. In this paper, we propose a VLSI placement flow to handle the large-scale mixed-size placement problem. The main idea of our placement flow is using a floorplanning algorithm to guide the placement of circuit elements. It consists of four steps: (1) With the multilevel framework, circuit elements are clustered into blocks by recursively partitioning; (2) a floorplanning algorithm is performed on every level of the blocks; (3) the macro cells are shifted by a macro shifting technique to determine their exact locations; (4) with each macro cell location fixed, a standard cell placement algorithm is applied to place the remaining objects. The proposed approach is tested on the IBM mixed-size benchmarks and the modern mixed-size (MMS) placement benchmarks. Experimental results show that our approach outperforms the state-of-the-art placers on the solution quality for most of the benchmarks.