The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 1996
Filed:
May. 26, 1995
Kent B Waterson, Everman, TX (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An integrated circuit (IC) with multiple input-only, output-only and combination input/output terminals which can be functionally tested at both the IC and circuit board levels includes programmably-designated, internal test signal buses for allowing functional tests to be performed upon portions of the IC not normally accessible via its outside terminals. Programmably-controlled signal switches allow input and output test signals to be routed directly to and from those functional areas of the IC sought to be tested. Further included are a logic circuit for logically ANDing all of the input signals and programmably-controlled output signal buffers for selectively driving each output terminal to a logic zero, logic one or high impedance state, thereby allowing tests to be conducted to ensure that the various input and output terminals are not electrically shorted to one another or circuit ground.