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:
Jan. 22, 2002
Filed:
May. 23, 2001
Thomas B. Chadwick, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A content addressable memory device comprises a NAND-NOR chain comprised an alternating sequence of NAND and NOR stages; the NAND stages, each including a first CAM cell comprising a first memory cell that stores a first data bit and a first compare cell that compares the first data bit with a first compare bit and generates a first compare signal indicating whether the first data bit matches the first compare bit and a logical NAND gate that combines the first compare signals of other first CAM cells in the NAND stage; the NOR stages, each including a second CAM cell comprising a second memory cell that stores a second data bit and a second compare cell that compares the second data bit with a second compare bit and generates a second compare signal indicating whether the second data bit matches the second compare bit and a logical NOR gate that combines the second compare signals of other second CAM cells in the NOR stage; and the NAND-NOR chain generating a match signal indicating a match of all the compare bits to all the data bits in the content addressable memory device.