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:
Oct. 07, 2008
Filed:
Jul. 30, 2007
Shunichi Iwanari, Kyoto, JP;
Shunichi Iwanari, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd, Osaka, JP;
Abstract
A ferroelectric memory provided in a memory system stores in advance set data for data write time to memory cells. The set data include two types of data that differ between in a power-on state and in a power-off instruction time, When power is turned on, the set data that are stored in the ferroelectric memory are stored and retained in a latch circuit by a control circuit. Based on the set data retained in the latch circuit, data writing is performed in the ferroelectric memory respectively in the power-on state and in the power-off instruction time. Thus, operations of the ferroelectric memory can be controlled with desired operation timings according to operating conditions for each memory system. Excessive stress application to the ferroelectric memory during the power-on state is prevented and endurance deterioration is suppressed, while data retention characteristics after power-off are improved.