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

[Dzar]

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 processor is simply hung and it did not reboot, as I would have expected.

The same thing happens when I write the cold reset bit in the reset manager or when the FPGA asserts it's version of the cold reset.

I would expect the cold reset to actually cold reset which, to me, means the HPS should boot from the BOOT ROM all the way though as it would as power up. But it does not.

Am I doing something wrong? What is the expected behavior when the power on reset (cold reset) is asserted, then deasserted?

[Ahmed_H_Intel1]

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]

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!

[Ahmed_H_Intel1]

Hi, First of all, I make sure that the compiled binaries are correct, it might let some files overwritten. So the question here first "Can you boot again if you power off and ON again?" If no, this means there is something went wrong in binaries compilation that cause this issue

[Dzar · Accepted solution]

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]

Hi, Yes this Rocket-Boards page show the solution of this issue, Please follow it to get it solved. https://rocketboards.org/foswiki/Documentation/SocBoardQspiBoot Possible solutions: https://rocketboards.org/foswiki/Documentation/SocBoardQspiBoot#Possible_Solutions Regards,