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:
Sep. 08, 1987
Filed:
Aug. 05, 1985
Masaki Kumanoya, Itami, JP;
Kazuyasu Fujishima, Itami, JP;
Hideshi Miyatake, Itami, JP;
Hideto Hidaka, Itami, JP;
Katsumi Dosaka, Itami, JP;
Yasumasa Nishimura, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor memory comprises memory cells (15-18, 27-30), a data writing terminal (1), a data readout terminal (48), transistors (3-10, 35-42), address signal input terminals (23-26), subdecode signal input terminals (43-46), driving signal generating circuits (49-52), parallel readout circuits (79-82) and test mode switching signal input terminal (53, 88). In writing of function test data for the memory cells, the driving signal generating circuits turn all of the transistors (3-10) on in response to a test mode switching signal with no regard to address signals, thereby to simultaneously write data in the memory cells (15-18). Further, in readout of the function test data for the memory cells, the parallel readout circuits read the storage contents of the memory cells (27-30) storing the test data in response to a test mode switching signal with no regard to subdecode signals. Logic circuit means (90, 91, 94) may be provided to output logical value corresponding to the test data stored in the memory cells when all of the logical values of the test data are at the same level.