Search: in
Clock recovery
Clock recovery in Encyclopedia Encyclopedia
  Tutorials     Encyclopedia     Videos     Books     Software     DVDs  

Clock recovery

Some digital data streams, especially high-speed serial data streams (such as the raw stream of data from the magnetic head of a disk drive) are sent without an accompanying clock signal. The receiver generates a clock from an approximate frequency reference, and then phase-aligns to the transitions in the data stream with a phase-locked loop (PLL). This process is commonly known as clock and data recovery (CDR).

In order for this scheme to work, a data stream must transition frequently enough to correct for any drift in the PLL's oscillator. The limit for how long a clock recovery unit can operate without a transition is known as its maximum consecutive identical digits (CID) specification. To ensure frequent transitions, some sort of encoding is used; 8B/10B encoding is very common, while Manchester encoding serves the same purpose in old revisions of 802.3 local area networks.

See also

fr:Synchronisation Symbole it:Clock recovery ja: pt:Recupera o de rel gio

Source: Wikipedia | The above article is available under the GNU FDL. | Edit this article

Search for Clock recovery in Tutorials
Search for Clock recovery in Encyclopedia
Search for Clock recovery in Videos
Search for Clock recovery in Books
Search for Clock recovery in Software
Search for Clock recovery in DVDs
Search for Clock recovery in Store


Clock recovery in Encyclopedia
Clock_recovery top Clock_recovery

Home - Add TutorGig to Your Site - Disclaimer

©2011-2013 All Rights Reserved. Privacy Statement