The Stamp9G20 does not boot when using a backup battery but works normally without. What is happening?

This can have two reasons, which both prevent the boot from DataFlash:

  1. If you just plugged in the Stamp and booted the system for the first time, this is most probably caused by some undefined value in the Reset Controller Mode register. To prevent this from happening remove the battery, switch on the system and than place the battery into the socket.
  2. The system already booted with a battery but you switched it off shortly after powering it. If you have done this while the last message of U-Boot was "WARNING: Caches not enabled", use the following update to fix the problem: http://www.armbedded.eu/node/696