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:
Aug. 01, 1995
Filed:
Nov. 16, 1992
Keith J Bertrand, Sunnyvale, CA (US);
Ampex Corporation, Redwood City, CA (US);
Abstract
A low cost, high speed data storage system provides word-by-word stale data detection while avoiding the need to both read and write a single memory location during a memory read operation. Two flag data storage bits are provided for each word location in addition to the normal data storage bits. As blocks of data are received by the storage system one of the two flag bits is assigned to the block on an alternating basis. Upon writing data to an address location, an assigned flag bit is written to a first state to indicate valid data. When reading, the corresponding assigned flag bit is output as a stale or invalid data signal and the nonassigned flag bit is set to a second state different from the first state in preparation for the next block of data.