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:
Jan. 24, 1995
Filed:
Jan. 27, 1994
Yoshiyuki Haraguchi, Hyogo, JP;
Yutaka Arita, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor memory device having a circuit for preventing the operation of a test mode includes a first terminal for receiving an externally applied high voltage exceeding a power supply potential, a second terminal for receiving an externally applied test mode signal and a high voltage detector for detecting that a high voltage signal has been applied through the first terminal. A test mode signal holding circuit is responsive to the high voltage detector and holds the test mode signal applied through the second terminal. A test circuit is responsive to the test mode signal held in the test mode signal holding circuit and performs a test in the semiconductor memory device. A disabling circuit is provided to disable the high voltage detector.