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:
Sep. 26, 2000
Filed:
Mar. 26, 1999
Terukazu Yusa, Tokyo, JP;
Michiaki Kuroiwa, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A ROM data read protect circuit according to the present invention comprises a non-volatile memory that stores a data for allowing or inhibiting reading of the ROM data and a logic circuit for control for controlling allowing or inhibiting of an operation for reading of data in a ROM according to the data stored in the non-volatile memory. When '0' is written in a first storage area of the non-volatile memory reading of the ROM data is inhibited, and when '0' is written in a second storage area of the non-volatile memory reading of the ROM data is allowed. A data can be written anytime in the first storage area but data can not be deleted from the first storage, so that the read inhibit mode is always effected in the initial state. A data can be written in the second storage area only when specific setting is executed but can not be deleted from the second storage.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile