Patent Document ID: 20090178013
Application ID: 12345399
Patent Flag: 0

Claim One:
1. Computer-readable media containing software, which when read and executed by a computer, causes the computer to carry out a method for implementing an engineering change order (ECO) by modifying a first integrated circuit (IC) layout for a first IC to produce a second IC layout for a second IC, wherein the first and second ICs include active cell instances interconnected by nets to form subcircuits, and include spare cell instances not interconnected by nets, the method comprising the steps of: a. comparing netlists describing the first and second ICs to identify additions and deletions, wherein additions are subcircuits formed by active cell instances and nets included in the second IC but not in the first IC, and wherein deletions are subcircuits formed by active cell instances and nets included in the first IC but not included in the second IC; b. reclassifying active cell instances of the first IC that form the identified deletions as spare cell instances of the first IC; and c. performing ECO re-synthesis comprising generating a technology independent model depicting circuit behavior of the identified additions and selecting spare cell instances of the first IC to implement the circuit behavior depicted by the technology independent model.