Integrated circuit device with internal inspection circuitry

Abstract

A highly-integrated semiconductor IC device includes a semiconductive substrate, on which an internal function circuit is arranged to have a first plurality of input terminals and a second plurality of output terminals. A logic circuit is arranged on the substrate and is connected to the internal circuit through the output terminals. The logic circuit has a third plurality of output terminals, which are less in number than the outputs of the internal circuit. These logic output terminals are coupled to the same number of inspection terminals, which are adapted to be coupled to a known electric inspection tool. The logic circuit processes the voltage signals appearing at the output terminals of the internal circuit so as to cause these signals to decrease in number. The output signals of the logic circuit are sent to the inspection terminals as monitor signals, based on which an inspection is carried out to determine whether the internal circuit operates normally.