Patent US 7,962,876

Static timing and/or noise analysis are performed on a netlist of an integrated circuit, to estimate behavior of the netlist and to identify at least one violation by said behavior of a corresponding requirement thereon, such as setup time, hold time or bump height in a quiescent net. Thereafter, effect of engineering change order (ECO) to correct the violation are automatically analyzed, based on the layout, the parasitics, the timing and/or noise behavior, and the violation, followed by generation of a constraint on the behavior (called “ECO” constraint), such as a timing constraint and/or a noise constraint. Next, the ECO constraint is automatically used, e.g. in a place and route tool, to select an ECO repair technique, from several ECO repair techniques that can overcome the violation. The selected ECO repair technique is automatically applied to the layout, to generate a modified layout which does not have the violation.