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Dzar's avatar
Dzar
Icon for Occasional Contributor rankOccasional Contributor
7 years ago
Solved

What should happen when I assert nPOR on my Cyclone V?

I want to reboot my HPS system in my Cyclone V. I can hold nPOR (power on reset) low when I power up and when I release it, my HPS boots just fine. But later, when I bring nPOR low, then high, my pro...
  • Dzar's avatar
    Dzar
    7 years ago

    Again, your answer is senseless. Of course I can boot again when I power cycle. What I cannot do is cold restart.

    It turns out this is a documented problem: https://rocketboards.org/foswiki/Documentation/SocBoardQspiBoot

    It would seem that Intel support would be aware of this and have not taken me more than a week of my own time to find. And, no, it has nothing to do with my binary. I hope my wasted time on this issue helps others find the needed solution.

Ahmed_H_Intel1's avatar
Ahmed_H_Intel1
Icon for Frequent Contributor rankFrequent Contributor
7 years ago
Hi, This issue happens mainly when something went wrong in the compilation process. Are you using the pre-compiled binaries to build your system? Are you booting from SD card? if yes, please check first the pre-compiled SD card image and let me know if you still have the same issue.
Dzar's avatar
Dzar
Icon for Occasional Contributor rankOccasional Contributor
7 years ago

I do not understand this.

  1. The nPOR PIN on the device should have nothing to do with any binaries. It's a physical pin doing physical things. It does not work as I would expect.
  2. The nPOR register from the HPS is a pyhsical thing that is not configrable, from anything I can see. It doesn't work as I expect, either.

I do not boot from an SD card. I boot from QSPI. We don' t have an SD card on our system. This is custom hardware so there are no pre-compiled binaries.

Please explain to me what I could configure/change in my FPGA bitfile or my source-code to possibly change the nPOR pin/register behavior. Could be I don't understand that, and it would be great if that's the issue, but I need to be pointed to some documentation on how to configure this, then. I simply don't see it.

Thanks!