Image Number 12 for United States Patent #7183570.
Test circuits located on semiconductor die enable a tester to test a plurality of die/ICs in parallel by inputting both stimulus and response patterns to the plurality of die/ICs. The response patterns from the tester are input to the test circuits along with the output response of the die/IC to be compared. The response patterns include one of expected data and mask data input on an output pad of the die/IC and the other of expected data and mask data input on another pad of the die/IC, which may be an input pad or an output pad. In addition to functional testing, scan testing of die and ICs is also possible.