This work proposes a timing-driven placement algorithm that uses a new type of timing analysis, which we call smooth timing analysis. It constructs the timing cost function as a smooth function of cell placement. In addition, for net modeling the algorithm uses a companion net routing that provides more accurate wire delay. The placement task is then formulated as a non-linear optimization problem. Experiments prove that the proposed method is applicable to build timing-driven placement solutions for designs with thousands critical cells. Experimental results on blocks from recent microprocessor designs show a 65% average improvement in total negative slack comparing to a leading industrial flow.
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