Abstract: A method of estimating capacitive cell load of cells in an integrated circuit (IC) design uses first maximum capacitive load values CMAX—LIB in calculating risk of electromigration failure in cells of the IC design. CMAX—LIB is saved for a cell whose risk of electromigration failure is acceptable. For a failed cell, a revised maximum capacitive load value CMAX—2 is reduced as the ratio of an actual current IACTUAL—1 relative to the electromigration current limit ILIMIT in the weakest element of the cell. A revised actual current IACTUAL—2 is obtained as a function of transition times with CMAX—2. CMAX—2 is saved for the cell if IACTUAL—2 is less than ILIMIT. Otherwise the steps of calculating CMAX—2 and IACTUAL—2 are re-iterated. CMAX—2 is reduced relative to CMAX—LIB for the first iteration and is further reduced relative to its previous value CMAX—2 for subsequent iterations.

Abstract: A layout method for an integrated circuit including vias connecting stacked metal layers through cuts in intermediate cut layers includes generating interconnection blockage and obstruction statements that define exclusion regions of the metal layers blocked by existing initial interconnections for routing additional interconnections. Shape, size and spacing data are generated for de-selection areas of the exclusion regions in the conductive layers. The de-selection areas are sufficiently far from the boundaries of the exclusion regions that cut spacing rules applied to the initial cuts within the de-selection areas do not block placement of additional cuts outside the exclusion regions of the conductive layers. Only those of the initial cuts within the exclusion regions that lie outside the de-selection areas are selected. Cut blockage and obstruction statements are generated for the selected cuts.

Abstract: A method of conducting timing analysis on an integrated circuit design includes performing a first routing operation on the design to generate a first routed design that includes redundant vias, and storing the first routed design in a first design database, and performing a second routing operation on the synthesized design to generate a second routed design that does not include redundant vias, and storing the second routed design in a second design database. Then, extractions are performed on the first and second designs and delay calculations are performing on the first and second extractions files. The first and second delay calculations are compared to determine a delay difference between the first and second designs and timing analysis is performed using the delay difference.

Abstract: A method of conducting timing analysis on an integrated circuit design includes performing a first routing operation on the design to generate a first routed design that includes redundant vias, and storing the first routed design in a first design database, and performing a second routing operation on the synthesized design to generate a second routed design that does not include redundant vias, and storing the second routed design in a second design database. Then, extractions are performed on the first and second designs and delay calculations are performing on the first and second extractions files. The first and second delay calculations are compared to determine a delay difference between the first and second designs and timing analysis is performed using the delay difference.