Patent ID: 6704676
Filing Date: 2004-03-09
Classification: G01R

Abstract:
A method for identifying an operating property of an integrated circuit, which comprises:ascertaining the operating property of the integrated circuit in a first test run, assigning a first digital identifier value to a first value of the operating property thus ascertained, and permanently storing the first digital identifier value in a first memory element disposed within the integrated circuit; subsequently ascertaining the operating property again in a second test run, assigning a second digital identifier value to a second value of the operating property thus ascertained, and permanently storing the second digital identifier value in a second memory element disposed within the integrated circuit; and feeding the first digital identifier value being stored and the second digital identifier value being stored to an OR gate and logically combining the digital identifiers in bit-by-bit ORing of bits of the first digital identifier value and the second digital identifier value to form an output identifier, and marking the integrated circuit in dependence on the output identifier.