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RLee42's avatar
RLee42
Icon for Occasional Contributor rankOccasional Contributor
5 years ago

question about dual-purpose pins used as normal I/O

I'm using 10M08SAE144I7 for the new design. Since the normal IO number is not enough for this design, in order to add more IO, I disable all the dual-purpose pins in the device by unticking all the options for dual-purpose pins. I think in this way these pins can be used as normal IO.

With this setting, I download .sof file to the FPGA, everything works fine. However, if I download .pof file into FPGA, the FPGA doesn't work at all after board reset. I guess maybe some dual-purpose pins can't be used as normal IO but not sure which ones are. Can you tell me which dual-purpose pins definitely can't be used as normal IO?

3 Replies

  • AminT_Intel's avatar
    AminT_Intel
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hello,

    The option "Enable nCOFIG, nSTATUS, and CONF_DONE pins" is needed for configuration. Can you enable that option and see if it works?

    Thank you.

    • RLee42's avatar
      RLee42
      Icon for Occasional Contributor rankOccasional Contributor
      5 years ago

      Thank you for your reply.

      I've already hard-wired the nCONFIG, CONF_DONE pins to control other components as the output pins, and the nSTATUS pin as GPIO connecting with another MCU. They are already used as the user I/O on the PCB so I think that option may conflict with the hardware.

      However, I've made an experiment that I jumped wire the nCONFIG, CONF_DONE to 3.3v through 10k resistor, then the FPGA can run successfully after reboot. I think these two pins should better be left alone and pull-up for the next version.