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:
Dec. 15, 1998
Filed:
May. 13, 1996
Takashi Orimoto, Tokyo, JP;
Ryo Ishikawa, Saitama-ken, JP;
Shigeto Suzuki, Tokyo, JP;
Katsuyoshi Kaneko, Tokyo, JP;
Takashi Shirasaka, Tokyo, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
An electronic device maintains data utilizing a ferroelectric memory, not requiring a backup power source voltage. Data such as schedule data and telephone number data is stored in a ferroelectric RAM which switches between a dynamic mode and a nonvolatile mode. When a clock mode is designated by a 'CLK' key, a memory control circuit causes the ferroelectric RAM to be switched to the nonvolatile mode to maintain the data stored therein. When a schedule mode or a telephone mode is designated by means of a 'Sch' key or a 'Tel' key, the ferroelectric RAM is switched to the nonvolatile mode to write/read data therein/therefrom. When it is detected that a battery voltage is lowered or the battery is removed from the electronic device, the ferroelectric RAM is switched to the nonvolatile mode to protect the stored data.