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:
Mar. 28, 1995
Filed:
Feb. 03, 1993
Tomotaka Ozeki, Toride, JP;
Yuzou Matsuo, Ibaraki, JP;
Hitachi Maxell, Ltd., Ibaraki, JP;
Abstract
A function of write protection against careless writing in a memory card is realized by means other than a mechanical switch. Existing address lines exceeding the capacity of a memory and an existing write control line are used as inputs to a gate circuit so that data can be written in the memory only in the case where a specific value can be decoded. Accordingly, a write address space is limited to a specific address space other than the lowermost address space. Accordingly, data cannot be written if the specific address space cannot be known. As a result, the function of write protection can be provided without using any switch and without introducing any nonstandardized terminal and any control signal.