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. 03, 1993
Filed:
Sep. 25, 1991
Applicant:
Inventors:
Shinichi Mori, Hyogo, JP;
Osamu Ueda, Hyogo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
365210 ; 36518901 ;
Abstract
A semiconductor storage device formed on a single chip includes a ROM, a RAM and an input/output port. When a mode setting signal designates a normal mode, access is made to one of the ROM, RAM and input/output port in response to an address signal. The ROM is accessed when the mode setting signal designates a ROM write mode and the address signal designates an address assigned to the ROM. A dummy data is output from a data input/output terminal when the mode setting signal designates the ROM write mode, the address signal designates an address outside an address region assigned to the ROM, and a read signal is applied to the device.