On handling the fixed-outline constraints of floorplanning using less flexibility first principles

In this paper, we propose an efficient approach on handling the fixed-outline constraints with the objectives of both improving the success rate and minimizing the wire length. Our approach uses the less flexibility first principles (Sheqin Dong, 2001) which are derived from human´s experience in solving rectangle packing problem in the daily life. In this construction based approach, success rate is guaranteed by using effective heuristics to guide the placement process. For the wire length objective, we use a wire length minimized solution gained by circuit partitioning and multilevel simulated annealing as a reference, where the topological relations derived from it are tried to be kept. We also apply a local grouping strategy and the minimal local wire length objective as supplements of wire length optimization. Experiment results show that our approach can achieve high success rates under tight outlines and comparable wire length with various aspect ratios