World Library  
Flag as Inappropriate
Email this Article

Quad data rate

Article Id: WHEBN0011284769
Reproduction Date:

Title: Quad data rate  
Author: World Heritage Encyclopedia
Language: English
Subject: Double data rate
Publisher: World Heritage Encyclopedia

Quad data rate

Quad data rate (or quad pumping) is a communication signaling technique wherein data are transmitted at four points in the clock cycle: on the rising and falling edges, and at two intermediate points between them. The intermediate points are defined by a 2nd clock that is 90° out of phase from the first. The effect is to deliver four bits of data per signal line per clock cycle.

In a quad data rate system, the data lines operate at twice the frequency of the clock signal. This is in contrast to double data rate systems where the clock and data lines operate at the same frequency.

QDR technology was introduced by Intel in their Willamette core Pentium 4 CPU, and is currently employed in their Atom, Pentium 4, Celeron, Pentium D, and Core 2 Processor ranges. This technology has allowed Intel to produce chipsets and microprocessors that can communicate with each other at data rates expected of the traditional FSB technology running from 400 MT/s to 1600 MT/s, while maintaining a lower and thus more stable actual clock frequency of 100 MHz to 400 MHz.

See also

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.