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. 28, 2004
Filed:
Nov. 20, 2000
Charles Arthur Kilmer, Essex Junction, VT (US);
Shanker Singh, Morgan Hill, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and system for detecting a failure in a dynamic random access memory (DRAM) array having a plurality of cells organized in a matrix fashion of rows and columns. The method includes reading the content of a first row of cells of the memory array during a first refresh cycle. After obtaining the content from the first row of cells, a first complement of the content is generated. The generated first complement is then written back to the first row of cells during the writeback operation of the first refresh cycle. During the subsequent refresh cycle, the first complement in the first row of cells is read and a second complement of the first complement is generated. Next, the original content in the first row of cells is compared with the second complement. In response to the original content not being equal to the second complement, a control signal is generated to indicate a failure in the memory array. In a related embodiment, the second complement is written back to the first row of cells during the subsequent refresh cycle writeback operation to restore the content in the first row of cells to its original value.