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. 16, 2003
Filed:
Jan. 28, 2002
Dieter Weiss, Munich, DE;
Giesecke & Devrient GmbH, Munich, DE;
Abstract
To permit safe writing of the pointer (P) pointing to the current record in a cyclic memory or ring memory, e.g. an EEPROM, the new record (D'# ) is written to the memory location (R ) containing the oldest record, and then the pointer (P) is updated. The pointer (P) consists of a first pointer (P , P *) and a second pointer (P , P *) redundant with respect to the first pointer. Each pointer contains a check value in the form of the inverse or complement code of the actual pointer. Due to the second pointer and the check value, the pointer is written with optimal safety. In case of a disturbance in the course of pointer updating, the old first pointer can later alternatively be recovered from the second pointer or the second pointer updated with the aid of the new first pointer.