Zynq ULPI with USB3320 over temperature USB Stream Hangs
We are using a XC7Z020-1CLG484I with a USB3320C-EZK connected to the PS as ULPI and PetaLinux 2018.3. We use the PS configure USB as GagetFS. The USB enumerates with the PC with no problem. We have problems when we start streaming data, certain boards fail over various temperature ranges. Some boards fail at lower temp 0'C, while warmer they are fine. Others around 25'C, and still others around 40'C. For each board outside the failure temperature, they are stable for many days. For each board this temperature for failure is very repeatable. We have one board that we cannot find a failure point, and another that fails quite nicely at 25'C. When it fails the data bus stops toggling, but the clock is still running. No error message comes up on the PetaLinux console. The trace length of the data and clock lines are 102mm +/- 27mm. Any ideas on what might be causing this? It seems to be a timing issue, but each board is a little different than the next.