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:
May. 29, 2007
Filed:
Sep. 14, 2005
Jeong-seok Chae, Goynag-si, KR;
Yoon-jay Cho, Seoul, KR;
Hyo-jin Kim, Suwon-si, KR;
Abstract
An input and output circuit includes a common input and output node, an abnormal voltage detector and a clock generating circuit. The common input and output node is used as an output node in a normal operation mode and used as an input node in a test operation mode where an abnormal voltage level is inputted to the common input and output node. The abnormal voltage detector generates an abnormal voltage signal based upon a detection of the abnormal voltage level at the common input and output node in the test operation mode. The clock generating circuit outputs a first clock signal to the common input and output node in the normal operation mode and outputs a second clock signal to an external circuit in response to the abnormal voltage signal in the test operation mode. Therefore, time and expenses for testing the input and output circuit may be reduced.