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:
Nov. 19, 2002
Filed:
Sep. 16, 1999
Kenneth S. Gray, Jericho, VT (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A redundant memory system includes an address bus, a random access memory, a content addressable memory, a replacement memory, and a data bus. The random access memory includes a number of addressable memory locations each accessed by a different one of a number of addresses provided by the address bus. The content addressable memory stores a number of defective location addresses each corresponding to a defective addressable memory location of the random access memory and responds to a match between an address provided by the address bus and one of the defective location addresses to activate one of a number of match lines. The replacement memory is coupled to the content addressable memory by the match lines and includes a number of replacement memory locations each accessed by activating a different one of the lines. The data bus receives addressable memory information from the random access memory when addressed by one of the addresses other than one of the defective location addresses and receives replacement information from the replacement memory in response to activate a respective match line. Defective information in the addressable memory is accessed in response to addressing by one of the defective location addresses, but output of the defective information is prevented during a read operation by the match line activation.