Clock frequency

Discussion in 'Embedded Systems and Microcontrollers' started by patheticz, Nov 3, 2009.

  1. patheticz

    Thread Starter New Member

    Nov 3, 2009
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    How do i generate a clock frequency for a FPGA chip?
    beside using a crystal
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    I dunno -- What are your requirements for frequency, stability, accuracy et cetra. How can we answer your questions if you fail to supply any information?
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    Get a TTL or CMOS oscillator. Mouser and Digi-Key carry a wide selection.

    Here is a link to a manufacturer so you can get an idea of the frequencies available - most are standard -http://www.well.com/~oe/OscFreqs.html
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    You can also use a PLL, divider, and a VFO
     
  5. patheticz

    Thread Starter New Member

    Nov 3, 2009
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    Sorry for the lack of information
    First of all, the query arose because i am designing an embedded controller for a a power switching module that is supposed to be able to function at swtiching freq of at least 10kHz.
    then i was looking through the specification sheet and realized that the Virtex 5 and virtex 6 FPGA can operate at 400MHz -1000MHz.
    Therefore, i was not sure what methods can i use to generate signal for the clock if i am going to use either of the FPGA
     
  6. Papabravo

    Expert

    Feb 24, 2006
    10,136
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    Those frequencies are maximums. There is absolutely nothing that says you have to operate at such frequencies. In any case the way you genrate 10 kHz from a crystal or other type of oscillator is to pick a convenient frequency and divide it down.
     
  7. auri_z

    New Member

    Feb 5, 2009
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    it depend your requiments,if you need stability use crystal if not oscilator from some R and C can make it..
     
  8. patheticz

    Thread Starter New Member

    Nov 3, 2009
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    i am a bit confused here.
    does that mean by having an oscillator of 10kHz, i can also generate frequency that is higher than that?
     
  9. Nanophotonics

    Active Member

    Apr 2, 2009
    365
    3
    No, you always generate a lower clock frequency from a higher one.
     
  10. beenthere

    Retired Moderator

    Apr 20, 2004
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