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:
Apr. 19, 1994
Filed:
Apr. 23, 1993
Yoshiyuki Haraguchi, Hyogo, JP;
Yutaka Arita, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
When a pre-shipment test of a SRAM is requested, a pulse signal PL having a pulse width exceeding a predetermined time length is applied through a terminal 62. A pulse width detecting circuit 80 detects the pulse width of the applied pulse signal to provide a holding signal HD. A test mode signal holding circuit 90 holds an externally applied test mode request signal TM' in response to the holding signal HD. After the completion of the pre-shipment test, pulse width detecting circuit 80 is disabled by a fusion of a fuse 71. Fuse 71 is fused after the pre-shipment test is conducted, whereby the test mode operation is prevented from undesirably occurring.