Statistical static timing analysis in non-linear regions

Abstract

A method is described for simulating the f-sigma timing path delay of an integrated circuit design when local transistor variations determine the stochastic delay. This is achieved by determining an estimated delay time for a first timing path using non-linear operating point analysis of local variations (NLOPALV). An operating point is calculated for each cell that is included in a timing path in the integrated circuit design. The f-sigma operating point of a cell-arc is a point on the cell-arc delay function (CADF). An f-sigma delay value is determined for each cell using the selected operating point on the CADF of the cell. The determined delay values of the plurality of cells in the timing path may then be combined to predict the estimated delay for the entire timing path. The method may be extended to deal with slew rate, predict hold time statistics, prune paths, and deal with convergent paths.