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. 24, 1988
Filed:
Jul. 21, 1987
Osamu Minato, Tokyo, JP;
Toshiaki Masuhara, Tokyo, JP;
Katsuhiro Shimohigashi, Musashimurayama, JP;
Shoji Hanamura, Kokubunji, JP;
Shigeru Honjyo, Hachioji, JP;
Nobuyuki Moriwaki, Kodaira, JP;
Fumio Kojima, Higashiyamato, JP;
Hitachi Ltd., Tokyo, JP;
Hitachi VLSI Eng. Corp., Tokyo, JP;
Abstract
A semiconductor memory is provided with automatic refresh means including a timer, a refresh counter and a refresh buffer each formed on a semiconductor chip mounted with an asynchronous memory, for automatically performing a periodic refresh operation on the basis of a basic clock signal which is generated in response to the detection of a logical change in the output of the refresh counter. The automatic refresh counter includes means for performing one of a read operation and a write operation which are based upon a regular address signal asynchronous with the periodic refresh operation, in preference to the periodic refresh operation.