Semiconductor device with mechanism for leak defect detection

A semiconductor device, comprising:

• a first chip;
• a second chip;
• a package containing said first chip and said second chip, wherein said first chip includes:
• a plurality of signal terminals connected to said second chip;
• a first power supply terminal connected to an exterior of said package;
• a second power supply terminal connected to an exterior of said package;
• a core circuit coupled to said plurality of signal terminals and said first power supply terminal;
• a plurality of first transistors coupled between the respective signal terminals and said second power supply terminal;
• and
• a plurality of second transistors coupled between the respective signal terminals and a ground potential,
• wherein said core circuit is configured to make said first transistors conductive and nonconductive alternately and make said second transistors nonconductive and conductive alternately at a time of test operation, such that one of a first transistor and a second transistor being conductive with respect to a given signal terminal requires another one of the first transistor and the second transistor to be nonconductive with respect to said given signal terminal.