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Altera_Forum's avatar
Altera_Forum
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17 years ago

I/O pins Pull-Up Resistors

Hello,

I am designing an embedded board with the MAX II EPM240T100C5N device. I am going to use some of the pins on the device to drive Output pins and to read Input pins. I would like to know if I should place pull-up/pull-down resistors on these pins and if so what values should I use?

A colleague mentioned that the EPM240T100C5N has internal pull-up resistors. If so, how do I specify to use them? I am using Quartus II 8.0sp1 and I can not find a way to set the "Programmable Pull-Up Resistor" for each pin.

Thank you,

Eitan

7 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Yes, MAX II has programmable pull-ups as Altera FPGAs and they are generally sufficient for static or low speed input signals, e. g. when reading a keyboard or a jumper.

    They can be set per pin in Quartus Pin Planner tool (You have to enable the respective column in context menu) or in Assignment Editor.
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Thanks for you answer.

    You said that I have to enable the respective column in context menu.... How?

    Also, in the Pin Planner Tool. I see all the pins and their I/O standard. Is that what you mean? If not, please direct me to right place.

    Thanks

    Eitan
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    There are also a detailed Quartus II handbook and online-help. I really wonder, if the said information is really that hidden and how other users have been able to find it.

    Anyway, see some visual hints below. When you have succesfully enabled weak pull-up resistors on any pin, you may want to checkout, how the option looks alike in Assignment Editor.

    A context menu, B.T.W. is a MS Windows feature, not specific to Altera. It's activated by right mouse-click, usually.
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    Hello,

    this is an old thread but it seems to match what I am looking for.

    I'd like to enable pull-up resistors on a MAX3000 device (EPM3064A). The Pin Planner in Quartus 13.0 sp1 does not show me any of the context options of 8.0 above. Can anybody point me in the right direction how to emable pull-up resistors for inputs? Either in QuartusII or in the Verilog source file.

    Also how do you set low power mode for the macro cells?

    Kind Regards
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    There are no programmable pull-ups in MAX3000 devices.

    MAX3000 has a Logic Option Assignment "Turbo Bit" which can be set in the assignment editor.
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    The pull-up resistors are only active during programming. Seems I did not read the data sheet properly....

    Thank you for the hint with the assignment editor !