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YigalB1's avatar
YigalB1
Icon for New Contributor rankNew Contributor
4 months ago
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RESERVED_INPUT_WITH_WEAK_PULLUP pins in DE1- Lite

I would like to use 3 pins of the 40 pin connector of the DE10-Lite for UART implementation (Tx,Rx,GND).

At first I was thinking of using V10 & V9 because they are top left on the connector, so easy to align. Yet they are far from the GND, so I am thinking now about W7 & V5, because they are near to the GND, so easy to use with 3 pins connector.

However, the pinout table claims they are "RESERVED_INPUT_WITH_WEAK_PULLUP". Does it mean they can't be configured to be 3.3V input and output for the UART needs?

Fpga Devkit
  • FvM's avatar
    FvM
    4 months ago

    Hi,

    according to DE10-Lite schematic, all GPIO connector pins are connected to RX/TX capable pins in 3.3V IO banks, also questioned GPIO_7 and GPIO_9. I presume, you are seeing "RESERVED_INPUT_WITH_WEAK_PULLUP" in the .pin file of a specific project. It reflects the pin assignments of the design, not the capabilities of the FPGA. "Reserved input" is the assignment of an unused pin. You need to assign intended pins to top level signals in Pin Planner tool or Assignment Editor.

4 Replies

  • FvM's avatar
    FvM
    Icon for Super Contributor rankSuper Contributor
    4 months ago

    Hi,

    according to DE10-Lite schematic, all GPIO connector pins are connected to RX/TX capable pins in 3.3V IO banks, also questioned GPIO_7 and GPIO_9. I presume, you are seeing "RESERVED_INPUT_WITH_WEAK_PULLUP" in the .pin file of a specific project. It reflects the pin assignments of the design, not the capabilities of the FPGA. "Reserved input" is the assignment of an unused pin. You need to assign intended pins to top level signals in Pin Planner tool or Assignment Editor.

  • AqidAyman_Altera's avatar
    AqidAyman_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 months ago

    I’m glad that your question has been addressed, I now transition this thread to community support. If you have a new question, Please login to ‘https://supporttickets.intel.com/s/?language=en_US’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you on your follow-up questions.