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Yamada1's avatar
Yamada1
Icon for Occasional Contributor rankOccasional Contributor
1 year ago
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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 ...
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  • FvM's avatar
    FvM
    1 year ago
    I can confirm that MAX10 pins are high impedance (> 10 Mohm) with 0 V supply.
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.