Patent ID: 7389488

Claim:
A method for finding a driving strength of at least one output pin of a target cell, comprising: determining whether the output pin of the target cell being a digital external pin; searching a plurality of candidacy standard cells in a standard cell library according to a last level device within the target cell which being connected to the output pin of the target cell and used for providing the driving strength to the output pin of the target cell when the output pin of the target cell being not the digital external pin; establishing a standard cell candidacy table according to the candidacy standard cells, wherein the standard cell candidacy table comprises driving strengths of the candidacy standard cells; performing interpolation calculation between the driving strengths of the candidacy standard cells so as to obtain the driving strength of the output pin of the target cell; and analyzing a partial circuit of the target cell so as to obtain the driving strength of the output pin of the target cell if the interpolation calculation between the driving strengths of the candidacy standard cells being incapable of obtaining the driving strength of the output pin of the target cell; wherein the partial circuit of the target cell comprises a partial circuit of the last level device and a partial circuit of at least one second last level device within the target cell which is connected to input terminals of the last level device and used for driving the last level device.