Identification of functional components in combinational circuits

摘要

Identifying the subcircuits in a detailed circuit description is a fundamental operation in both circuit validation and design recovery. Existing identification techniques rely on finding an exact match for a subcircuit structure within the description. These techniques fail to identify subcircuits that are functionally equivalent but have been obfuscated because a different technology is being used or because the design has been optimized. This report presents a mechanism for identifying subcircuits that are functionally equivalent, irrespective of obfuscating details. It also describes the initial progress made in transforming detailed circuit descriptions into corresponding descriptions based on subcircuits. Such progress depends on enumerating all of the candidate subcircuits within the original detailed description and functionally matching each candidate. The report presents unique solutions for reducing the amount of computation needed for this enumeration.