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Altera_Forum's avatar
Altera_Forum
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7 years ago

unused prn/clrn inputs

Noob question if I may.

In the schematic editor, how should I pull up unused prn/clrn inputs to a flip flop?

Currently I tie them to an unassigned input pin default vcc. Circuit works fine, but that doesn't seem right.

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Hi,

    --- Quote Start ---

    In the schematic editor, how should I pull up unused prn/clrn inputs to a flip flop

    --- Quote End ---

    Using Assignment Editor you can pull up, check the screenshot.

    https://www.altera.com/support/support-resources/operation-and-testing/io/io-features.html#programmablepullupresistor

    Let me know if this has helped resolve the issue you are facing or if you need any further assistance.

    Best Regards

    Vikas Jathar

    (This message was posted on behalf of Intel Corporation)
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    I know about pin pullups, thanks. My question was about unused flip flop inputs. Using discreet logic I would pull these up. Currently I'm assuming if I leave them unconnected the synthesizer will optimise the function out. Seems to work.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Hi,

    Can you please brief your question with Schematic editor (screenshot), what are you trying to do & what issue are you facing?

    Best Regards

    Vikas Jathar

    (This message was posted on behalf of Intel Corporation)