Effective algorithm for optimal initial solution in mixed-mode detailed placement

This paper presents a new detailed placement algorithm in the mixed block and standard cell IC design. Novelty of this algorithm lies in an optimum solution at initial stage by using network-flow method to satisfy row capacity constraint and the thought of LPP to resolve overlaps. Moreover, divide-and-conquer strategy and other simplified methods are adopted to minimize complexity. Experimental results show that the algorithm can get an average of 16% wire length improvement on PAFLO in comparing CPU time.