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. 13, 1999
Filed:
Apr. 21, 1998
John M Callahan, San Ramon, CA (US);
Enable Semiconductor, Inc., Milpitas, CA (US);
Abstract
A row identification circuit identifies which redundant-row fuse has been blown in a memory integrated-circuit by electrically interrogating the integrated-circuit using a switching circuit internal to the memory integrated-circuit. N data output terminals of the memory integrated circuit provide an n-bit binary-coded word which identifies a defective row. To bring out the binary fuse data, the chip is put into a test mode with a TESTF signal which shuts off a normal CMOS transmission gate as well as a latch feedback transmission gate and which turns on another CMOS transmission gate to pass a defective row address bit FUSEB to a data output terminal for the memory device. A switching circuit selectively switches either a defective row address bit TESTB or a data input signal DIN to a data output terminal of the memory integrated circuit. The switching circuit is selectively controlled by a test mode control signal TESTF. For an entire memory integrated circuit, a plurality of switching circuits are provided for each bit of the code word for providing the defective row number.