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:
Jun. 22, 1999
Filed:
Aug. 27, 1997
Applicant:
Inventors:
Richard S Gunsaulus, Highland Heights, OH (US);
Otomar S Schmidt, Richmond Heights, OH (US);
Assignee:
Allen-Bradley Company, LLC, Milwaukee, WI (US);
Primary Examiner:
Int. Cl.
CPC ...
G06F / ; H03M / ;
U.S. Cl.
CPC ...
371 511 ; 371 491 ;
Abstract
A memory system uses standard memory devices not normally supporting parity bits. Parity bits for multiple memory devices are stored in a dedicated parity device shared among multiple memory devices. Inadvertent erasure of the parity information, when writing to a single memory device, is prevented by a prereading of the parity device prior to a writing to the single memory device. Special circuitry stores the preread parity information and merges it back with the calculated parity bit for the written data to preserve complete parity information.