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Altera_Forum's avatar
Altera_Forum
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18 years ago

Using GCLK by a Quartz Crystal

Hi all,

Can I use a quartz crystal to drive the GCLK pin of FPGAs? I mean just like the microcontroller XTAL pin which needs a quartz crystal with 2 capacitors?

Thanks in advance.

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    There have been some discussions of this on the comp.arch.fpga newsgroup. It isn't at all reliable.

    Leon
  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    That's an interesting question, though! Has anybody here ever tried to use the FPGA itself to build a crystal oscillator? It's quite easy to have a simple inverter from on pin to another. So after configuration, the FPGA should oscillate with the crystal. Any experience with that?

  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    No, you need a crystal oscillator or an unbuffered CMOS inverter to build an oscillator.