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.

Date of Patent:
Dec. 23, 2003

Filed:

Nov. 01, 2002
Applicant:
Inventors:

Masaki Okuda, Kawasaki, JP;

Hiroyuki Kobayashi, Kawasaki, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C 1/604 ;
U.S. Cl.
CPC ...
G11C 1/604 ;
Abstract

A phase adjustment circuit delays an external clock signal to generate an adjusted clock signal. A phase comparator compares phases of the external clock signal and the adjusted clock signal, and outputs a phase adjustment signal for adjusting a delay time of the phase adjustment circuit. A data output circuit outputs read data to a data terminal in synchronization with the adjusted clock signal. A data input circuit receives write data supplied to the data terminal, in synchronization with the adjusted clock signal. When performing input of the write data and output of the read data successively, switching control between the input operation of the write data and the output operation of the read data only has to be completed within one clock cycle. The clock cycle can thus be reduced to the time required for the switching control. Consequently, maximum frequency of the external clock signal can be increased.


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