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:
Jul. 27, 1999
Filed:
Jul. 03, 1996
Kiyoshi Nishimura, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
In a data security system, after completion of writing into a P-ROM, a switching circuit is open to thereby disconnect the connection between an internal bus and an external bus. In this state, it is impossible to read the contents out of the P-ROM. To read the contents, a protection releasing terminal is brought to 'H'. This causes a switching circuit to conduct to make possible read-out. The 'H' signal is simultaneously supplied to an erasion signal generating circuit to erase a part selected by an erasion selecting switch. Secrecy is substantially maintained because a program in the P-ROM is not entirely read. The remainder except the erased portion can undergo checking for correctness of writing.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile