Patent ID: 7640469

Claim:
An electronic element comprising: an electronic circuit to be tested, wherein the electronic circuit comprises a plurality of storing components coupled in series to form scan chains, wherein each scan chain has an input terminal to receive a scan test signal sequence to test the storing components of the scan chain, and an output terminal, an actual value signal of the scan chain being provided at the output terminals of the scan chain in response to the scan test signal sequence which is shifted through the scan chain; and a comparator circuit having first input terminals and second input terminals and an output terminal, each of the output terminals of the scan chains respectively being coupled to one of the a first input terminals, the second input terminals to receive desired value signals, and the comparator circuit to compare the actual value signals provided at the output terminals of the scan chains with the desired value signals and provide the comparison to the output terminal of the comparator circuit; wherein the electronic element is set up to process signals of a 3-value logic, wherein one of the logic levels of the 3-value logic is formed as a masking logic level to mask undefined states of the actual value signals that occur in the comparator circuit.