U.S. patents available from 1976 to present.
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Dynamic memory device, a memory module, and a method of refreshing a dynamic memory device

Patent 5629898 Issued on May 13, 1997. Estimated Expiration Date: Icon_subject February 29, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Inventors

Assignee

Application

No. 607977 filed on 02/29/1996

US Classes:

365/222, Data refresh365/195, Inhibit365/230.03, Plural blocks or banks365/233, Sync/clocking365/236Counting

Examiners

Primary: Nelms, David C.
Assistant: Niranjan, F.

Attorney, Agent or Firm

Foreign Patent References

  • 51-127629 JP. 11/19/1976
  • 61-217988 JP. 09/19/1986

International Class

G11C 007/00

Foreign Application Priority Data

1995-03-03 JP

Abstract

A period pulse corresponding to the shortest information retention time of those of dynamic memory cells is counted to form a refresh address to be assigned to a plurality of word lines. A carry signal outputted from the refresh address counter is divided by a divider. For each of said plurality of word lines assigned with the refresh address, one of a short period corresponding to an output pulse of a timer or a long period corresponding to the divided pulse from the divider is stored in a storage circuit as refresh time setting information. A memory cell refresh operation to be performed by the refresh address is made valid or invalid for each word line according to the refresh time setting information stored in the storage circuit and the refresh time setting information itself is made invalid by the output pulse of the divider.

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