/*!
    \file    readme.txt
    \brief   description of the backup data demo

    \version 2025-08-08, V1.3.0, firmware for GD32E51x
*/

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*/

  This demo is based on the GD32E517Z-EVAL-V1.0 board, it shows how to store user data 
in the backup data registers.
  As the backup domain still powered by VBAT when VDD is switched off, its contents
are not lost if a battery is connected to VBAT pin. 
  JP1 must be connected to 3.3V before the board is powered up, and LED2, LED3 and 
LED4 are on. After an external reset, LED2 and LED3 are off, LED4 is on. Change JP1 
connected to external battery, then execute a power-down and power-up operation, 
LED1, LED3 and LED4 are on.

  BT1 should have a 3.3V battery, JP1 can change the VBAT source.  
