After an unknown event, the real-time circuit on the SCM20260N enters a state where it cannot sleep for more than a few minutes. Any larger time value for Power.Shutdown causes an immediate reset. The only solution is to reconnect the backup battery (CR20320) to the SCM20260N. I do not use pin PA0 in the application. PA0 is used for wake-up only. RTC is valid.
This works correctly:
Power.Shutdown(true, rtcC.Now.AddSeconds(10 * 60));
This causes an immediate reset.
Power.Shutdown(true, rtcC.Now.AddDays(1));
I also noticed the same behavior on the SCM20260D Dev Board Rev C, there I reconnected the entire SCM20260D module for correct operation.
How can I restart the real-time circuit without disconnecting the backup battery?