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Altera_Forum's avatar
Altera_Forum
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18 years ago

Pull Up Resistors

I've added the following assignment to enable a pull up resistor on an input pin on a 20K100E device.

set_instance_assignment -name PASSIVE_RESISTOR "PULL-UP" -to my_input_signal

When I compile the project there isn't any reference to this pull up in the warnings but I can't find any confirmation that it's been included either.

Any ideas on how to confirm whether or not there in a pull up on the pin?

Thanks

Ben

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    I don't have an apex design in front of me, but I believe opening the Compilation Report and going to Fitter -> Resource Utilization and there will be three sections, Input Pins, Output Pins and Bidir Pins, with details like this on each one. (This information is definitely there for newer families.)

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    Thanks for replying but there isn't a pull up column in that file and there isn't any mention of pull ups in the .pin file.

    Do you know if you can actually enable pull ups for these devices? I assumed there would be a warning if I couldn't.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    I don't think there is one, which would make sense why there is no column for it.