Method for use of hierarchy in extraction

摘要

A method and system for extracting circuit characteristics from a circuit design comprises extracting first cell characteristics from a portion of said circuit design using a first set of environmental conditions. The invention then extracts second cell characteristics from the portion of the circuit design using a second set of environmental conditions. The invention determines a difference between the first cell characteristics and the second cell characteristics and labels a placeability of the portion of the circuit design based on the difference.