Patent ID: 7913144

Claim:
A diagnosis device for diagnosing a fault location of logical behavior caused by a physical defect existing in a multi-layered logic circuit, by representing the logical behavior with different distinction symbols assigned onto fanout branches, an active element of the logic circuit being connected between different layers and to one or a plurality of passive elements, the passive element including a connection element for connecting active elements in the logic circuit between different layers, the diagnosis device comprising: symbol injection means for an active element for assigning distinction symbols, which represent logical behaviors by one or a plurality of defects existing in the active element and/or in each of a plurality of signal lines from fanout branches which can propagate output signals of the active element, to each of a plurality of signal lines from fanout branches which can propagate output signals of the active element; symbol injection means for a passive element for assigning new extended distinction symbols, which represent logical behaviors by one or a plurality of defects existing in the passive element and/or in each of a plurality of signal lines from fanout branches which can propagate output signals of the passive element, to each of a plurality of signal lines from fanout branches which can propagate output signals of the passive element; and fault locating means for locating the fault location by making use of distinction symbols assigned by the symbol injection means for an active element and the symbol injection means for a passive element.