Patent ID: 8219953

Claim:
An apparatus for designing a circuit, the circuit containing a plurality of metal paths, the apparatus comprising: at least one non-transitory computer readable medium; and a non-transitory computer readable program code stored on said at least one non-transitory computer readable medium, said non-transitory computer readable program code comprising instructions for: receiving a value specifying a desired reliability measure for electromigration (EM) to be provided for said circuit; receiving a first current density limit and a second current density limit, wherein said first current density limit represents a maximum value of current density corresponding to said desired reliability measure, and said second current density limit represents a maximum value of current density corresponding to a maximum allowed temperature rise in a metal path; determining a duty cycle parameter representing a ratio of an average current and an rms (root mean squared) current in a metal path for each metal path contained in said plurality of metal paths; determining for each metal path contained in said plurality of metal paths a maximum current allowed to flow based on the duty cycle computed, said first current density limit and said second current density limit; and performing a reliability analysis of said circuit.