On-board testing circuit and method for improving testing of integrated circuits

Abstract

A system allowing testing a plurality of integrated circuits mounted on a common substrate is described. The testing system includes a failure processor mounted on the substrate. The substrate has a first signal port adapted to be coupled to a testing device. The failure processor has a second signal port coupled to the first signal port and a plurality of test ports corresponding in number to the number of integrated circuits mounted on the substrate that are to be tested. Each of the test ports may be coupled to a respective one of the integrated circuits. The failure processor is constructed to apply stimulus signals to each of the integrated circuits and to record response signals generated by each of the integrated circuits in response to the stimulus signals provided to the integrated circuits. The failure processor is further constructed to provide report data based on the response signals and to couple the report data from the second signal port to the first signal port. As a result, many integrated circuits under test may share the first signal port through the failure processor, because the integrated circuits under test are not providing output data on the first signal port to an external test data evaluation apparatus. The efficiency with which integrated circuits may be tested is thereby increased.