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

    \version 2026-02-25, V1.0.4, firmware for GD32F50x
*/

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*/

  This demo is based on the GD32F503V-EVAL-V1.1 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. 
  JP3 must be connected to 3.3V before the board is powered up, LED1 is off, LED2 and LED3 are 
on. After an external reset, LED1 and LED2 are off, LED3 is on. Change JP3 connected to external 
battery, then execute a power-down and power-up operation, LED1 and LED3 are on.

  BT1 should have a 3.3V battery, JP3 can change the VBAT source.
