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:
Apr. 25, 2000
Filed:
Feb. 05, 1999
Applicant:
Inventor:
Jun Setogawa, Hyogo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
365233 ; 36518904 ; 36518907 ; 365194 ;
Abstract
When the frequency of an external clock signal is higher than a prescribed frequency in an SDRAM, an output signal from a clock frequency detection circuit is at an L level, a transfer control signal is fixed to an H level, and first and second data buses are coupled together. Thus, a malfunction when the transfer control signal attains an H level in a pulse manner while read data is not output to the first data bus can be prevented. Accordingly, an SDRAM having a larger operating frequency range can be obtained.