Patent ID: 8813006

Claim:
A non-transitory machine readable media having instructions stored thereon that when executed by a machine causes the machine to perform operations comprising: determining input transistors directly coupled to one or more input pins but not one or more output pins of a subcircuit, the subcircuit including a number of transistors; performing a timing analysis over one or more timing arcs of the subcircuit between the one or more input pins and the one or more output pins of the subcircuit to determine nominal subcircuit timing of the one or more timing arcs; performing an initial sensitivity analysis of subcircuit timing for a single perturbation of a first parameter in each transistor of the subcircuit over the one or more timing arcs; performing an input slew sensitivity analysis for within die process variations over the one or more timing arcs of the subcircuit between the one or more input pins and the one or more output pins of the subcircuit by perturbing the input transistors for one or more process variations over a plurality of input slew rates; and annotating results of the initial sensitivity analysis and the input slew sensitivity analysis to timing information of the subcircuit in a cell library; wherein the number of transistors to perturb to perform the input slew sensitivity analysis for within die process variations over the one or more timing arcs is fewer to reduce the number of simulations to characterize the subcircuit for within die variations.