3.1.4 VDDBU Backup Power

A 3V CR1220 coin cell (to be placed in the BT1 battery holder) is used to permanently maintain the VDDBU voltage.

This function allows the user to shut down the MPU and the system, thus entering Low-Power mode while maintaining the custom configuration that was previously set in the MPU backup area.

Jumper JP17/J85 must be in place for the proper operation of the MPU. It can be removed if the user needs to return the MPU to the initial configuration by resetting the Backup registers (BUREG).