MangOH Yellow - time/date doesn't persist with ulpm

Hello everyone,

I am hoping this isn’t a re-post, but I did not see anyone else report this issue I am noticing; so here it goes… When configuring the MangOH Yellow for ulpm it appears that after a ulpm cycle the system’s date and time do not persist. Instead I see that the date and time revert back to January 6th 1980. Additionally I noticed this issue also appears to occur if the device loses power abruptly (removing the USB cable while the device is on).

Does anyone know if there is a solution to getting the date/time to persist after a ulpm cycle? For what I am using this board for this is kind of a big deal if there is no solution. I didn’t see anyone else report this issue here, so I hope I am not alone here.

If anyone has any ideas/solutions I would greatly appreciate the help!

Thanks in advance!

Legato Version: 19.10.1
Low Power Manager Firmware Version: 002.013

Hi Steffono. I have seen the same thing with our system: WP77xx with custom hdw. My interp is that in achieving ultra low power consumption the choice was made not to keep a clock running. In my system, one of the early steps of a power-up after ULPM is to get in touch with the time/date server and re-establish the clock. So the only way to tell that the clock was ever wrong or off is to look at the beginnings of the log for that power-up.
If your system doesn’t quickly re-establish the correct time, it probably means that the stored uri for the time/date server is not properly saved. Others might chime in on where that is located.