We have a strange behavior when we run the DDR3 stress test (v2.10) on our iMX6SoloX boards.
We have calibrated the memory bus at 396 MHz and it works very well.
We can run our boards in stress test mode over extensive periods of time (also in a temperature chamber). It works perfect on 380 MHz, 396 MHz, etc.
However, it we set the frequency sweep to 360-440 MHz, it appears that the iMX6SoloX freeze when switching from 380 to 396 MHz. Not immediately, but after 5-10 switches. The behavior is not temperature dependent. The freeze will eventually always happen. We see the same behavior on all boards we have tested.
Note that the system does not freeze during the stress tests but (it appears to be) when changing operating frequency. The printouts from the stress test at 380 MHz show success but we do not see any printouts from the 396 MHz test that is about to start next.
It can possibly be the GUI application that freeze.
It can possibly be the iMX6SoloX that freeze.
It can possibly be USB communication that is lost.
We cannot really determine where the problem is.
It is worth noting that the old stress test application (v1.0.3) does not give this freeze problem. This application takes much longer so we do not have the same amount of data from this run. Up until now we have at least not experienced any freeze on this version of the stress test.
Can it be a problem in the application that runs the stress test on the iMX6SoloX (typically in the process of switching between frequencies)?
Is there any other tests that we can do to track down the problem?
Is the source code available for the stress test application that is downloaded?