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:
Aug. 23, 2011
Filed:
Jul. 08, 2009
Shinobu Asayama, Kanagawa, JP;
Toshio Komuro, Kanagawa, JP;
Shinobu Asayama, Kanagawa, JP;
Toshio Komuro, Kanagawa, JP;
Renesas Electronics Corporation, Kawasaki-shi, Kanagawa, JP;
Abstract
Disclosed herewith is a semiconductor device having an SRAM cell array capable of easily evaluating the performance of transistors and the systematic fluctuation of wiring capacity/resistance. In order to form an inversion circuit required to form a ring oscillator, a test cell is disposed at each of the four corners of the SRAM cell array and the ring oscillator is operated while charging/discharging the subject bit line. Concretely, the ring oscillator is formed on a memory cell array and the ring oscillator includes test cells disposed at least at the four corners of the memory cell array respectively. At this time, a wiring that is equivalent to a bit line is used to connect the test cells to each another.