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:
Dec. 04, 2007
Filed:
Nov. 12, 2004
Mark David Bellows, Rochester, MN (US);
Ryan Abel Heckendorf, Rochester, MN (US);
Mark David Bellows, Rochester, MN (US);
Ryan Abel Heckendorf, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A structure of sequencers, a method, and a computer program are provided for performing initial and periodic calibrations in an XDR™ memory system. A memory controller that performs these calibrations is divided into identical, independent halves, with each half containing a Current/Impedance Calibration (i/z Cal) sequencer and six Bank sequencers. The i/z Cal sequencer contains three pathways that perform the XIO current and termination calibrations, and the XDR™ DRAM current and termination impedance calibrations. Each Bank sequencer contains normal read and write operation pathways that are reused to accomplish receive setup, receive hold, transmit setup, transmit hold, XIO receive, and XIO transmit timing calibrations. Initial and periodic calibrations are necessary to ensure the precise transfer of data between the XIOs and the XDR™ DRAMs.