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Altera_Forum's avatar
Altera_Forum
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17 years ago

Cyclone III Dedicated clock inputs during configuration

Hi All:

We have a question about the state of Dedicated Clock Inputs during configuration on Cyclone III devices.

The handbook says that the "Programable Pull-up Resistors" are not available on the dedicated clock input pins.

Is this also true during configuration? IE they will not have a weak pullup during configuration?

If the dedicated clock inputs are not used, and you have unused pins set as input w/weak pullup With the unused clock inputs not have the pullup in this case as well?

Thanks

Pete

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I'm pretty sure it means they don't physically exist, and therefore there is no way for them to have a pullup during configuration. If you're not using the dedicated clock input, you're supposed to tie it off(directly high or low, or a pull-up/down).

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    --- Quote Start ---

    If you're not using the dedicated clock input, you're supposed to tie it off(directly high or low, or a pull-up/down).

    --- Quote End ---

    Hello Rysc,

    What is the implication if one doesn't tie off the unused dedicated clocks?
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I wouldn't expect dramatic consequences, only a slightly increased current consumption is likely to happen.