Patent ID: 7124385

Claim:
A method for generating an integrated circuit layout, comprising the steps of: receiving an integrated circuit netlist describing a plurality of transistors and a plurality of conductors for interconnecting the plurality of transistors, each of the plurality of transistors having a width in a layout corresponding to the integrated circuit netlist; determining that more than one of the plurality of transistors are the widest transistors and that the more than one widest transistors all have the same width; folding only one of the widest transistors to produce a folded transistor that is electrically equivalent to the widest transistor, the folded transistor having at least two fingers, each finger having a smaller width than the width of the widest transistors; creating a fold solution for the layout with the one folded transistor, wherein the steps of folding and creating are repeated for each of the plurality of transistors until all of the plurality of transistors have been folded at least once; wherein the plurality of transistors includes a plurality of N-channel transistors and a plurality of P-channel transistors and the steps of folding and creating are repeated for each transistor of the plurality of N-channel transistors to create an independent N-channel fold solution list and the steps of folding and creating are repeated for each transistor of the plurality of P-channel transistors to create an independent P-channel fold solution list; the method further comprising the steps of: receiving a dependency map for listing dependent pairs of N-channel and P-channel transistors from the integrated circuit netlist; summing the widths of the dependent pairs to generate a height lower bound; folding transistors of the dependent pairs having a height lower bound greater than a predetermined amount to produce an N-channel dependent fold list and a P-channel dependent fold list; and merging the independent N-channel fold solution list, the independent P-channel fold solution list, the N-channel dependent fold list and the P-channel dependent fold list to produce an initial fold solution list.