We are struggling with a DM365 design. During first prototype run, things looked good and we're able to run Linux and run many tests. Only very minor changes were made to the PCB and on the current spin we are seeing issues where the system will run for a short while and then lock up. Only a HW reset will bring the board back.
To date the first run of prototypes do not see this issue, only boards from the second run. The issue appears to be easier to reproduce when we've set the DM365 to record out to USB.
We have followed all DDR2 routing guidelines and this section of the board had no changes from rev1 to rev2. All boards being tested are running the same SW.
We have looked at the power rails and 1V8, 3v3 look clean. 1V35 has a 10Hz noise due to the video recording (processing 10 frame per second), ripple Vp-p=140mV. Tried to increase 1V35 to 1V4 that didn’t help.
Reviewed \TRST and added a pull down to make sure it's set properly.
Looking for some help and suggestions?
Thanks
j