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. 05, 1991
Filed:
Mar. 03, 1989
Peter C DiGiulio, Easton, CT (US);
Warren G Hafner, Lake Carmel, NY (US);
Henry Stalzer, Danbury, CT (US);
Other;
Abstract
An electronic postage meter with a non-volatile memory security circuit apparatus is disclosed. The security circuit comprises means for limiting the amount of time the memories may be continuously enabled, means for preventing simultaneous enabling of both memories and means for preventing the write enabling of a memory if the write enable signal is active before a memory select signal is active. The circuit prevents memory access when a conflict is sensed across in an output related to the non-volatile memories. The security circuit provides additional protection to the non-volatile memory so that valuable critical accounting information located therein cannot be modified or destroyed.