Fixed-outline floorplanning based on common subsequence

In this paper, an efficient algorithm addressed to fixed-outline floorplanning is presented. The proposed algorithm takes sequence pair as representation and has following main features: (1) it uses common subsequence and penalty function to bound the variations of the widths of the floorplans to a quite small range; (2) a simple cost function which has no items about the heights of the floorplans is presented; (3) two-stage simulated annealing is adopted to minimize the wirelength. Experimental results show that the proposed algorithm is superior to other state-of-the-art fixed-outline floorplanning approaches in the following aspects: (1) it can achieve high successful probabilities, even with tight outlines and large aspect ratios given; (2) the feasibility of the given outline will be evaluated at the beginning of the floorplanning, which can save much time when infeasible outline is given. Besides, the experimental results on wirelength optimization are also promising.