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Yamada1's avatar
Yamada1
Icon for Occasional Contributor rankOccasional Contributor
1 year ago
Solved

About MAX10 IO pin pull-up

It would be helpful if you could tell me about the pull-up of the IO pin of MAX10.

1) In the UG-M10PWR, it is stated that the tri-state and weak pull-up resistors are enabled during power-up due to the POR circuit, but is this also the case during the power-down sequence?

2) If the power is completely turned off, will the weak pull-up resistor on the I/O pin not work? (In other words, will the I/O pin be floating?)

We apologize for the inconvenience and appreciate your understanding.

Generic Io
Power
  • FvM's avatar
    FvM
    1 year ago
    I can confirm that MAX10 pins are high impedance (> 10 Mohm) with 0 V supply.

7 Replies

  • AqidAyman_Altera's avatar
    AqidAyman_Altera
    Icon for Regular Contributor rankRegular Contributor
    1 year ago
    1. Based on the Max 10 Handbook, the output buffers of the Intel MAX 10 device are turned off during system power-up or power-down. The Intel MAX 10 device family does not drive out until the device is configured and working in the recommended operating conditions. The I/O pins are tri-stated during power up or power down. The internal weak pull-up resistors are disabled by default during power up. You need to enable the internal weak pull-up resistors through the Intel Quartus Prime software.
    2. The weak pull-up resistor in Intel MAX 10 device I/O elements (IOE) keep the I/O pins from floating. Before or during power down, you can drive signals into I/O pins, dedicated input pins, and dedicated clock pins without damaging the Intel MAX 10 devices.
    • Yamada1's avatar
      Yamada1
      Icon for Occasional Contributor rankOccasional Contributor
      1 year ago

      Thank you for answering.

      Thank you for explaining the details. Is it okay to understand the following?

      1) Weak pull-up is disabled by default, but can be enabled through settings from the Quartus Prime software.

      2) When weak pull-up is enabled, it prevents I/O pins from floating during power-up and power-down.

      3) I/O pins are floating when the power is completely off.

      Also, I apologize for the repeated questions, but I would appreciate it if you could explain the following points.

      4) If weak pull-up is enabled, are the I/O pins floating from power-on until POR operates? Or will the weak pull-up be enabled from the moment the power is turned on, and the power supply voltage will be visible during power-up?

      We apologize for the inconvenience and appreciate your understanding.

      • FvM's avatar
        FvM
        Icon for Super Contributor rankSuper Contributor
        1 year ago

        Hi,
        my reading of MAX10 device handbook gives a slightly different picture. There are basically three different states:
        1. Supply voltage below POR threshold
        According to Fig. 2.7 and related description, weak pull-up is unconditionally enabled, drivers are disabled.
        2. Configuration mode
        State of weak pull-up is controlled by ICB, default is enabled. See Table 2.5.
        3. User mode
        Weak pull-up is controlled by general and pin specific configuration.

        Regarding state during power down and missing supply. If power down triggers POR comparator, same situation as power up. Zero supply - not specified. Depends on Vgs,th of pull-up transistor, the question sounds somewhat sophistic to me.

  • AqidAyman_Altera's avatar
    AqidAyman_Altera
    Icon for Regular Contributor rankRegular Contributor
    1 year ago

    Hello Yamada,


    I wish to follow up with you.

    Is there any more support needed on your question?


    Regards,

    Aqid


  • AqidAyman_Altera's avatar
    AqidAyman_Altera
    Icon for Regular Contributor rankRegular Contributor
    1 year ago

    I hope the previous response was sufficient to help you proceed. As we do not receive any response from you on the previous reply have been provided, please login to ‘https://supporttickets.intel.com’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you by replying to this thread.