/*!
    \file    readme.txt
    \brief   description of the backup data demo
    
    \version 2026-02-03, V1.9.0, firmware for GD32E10x
*/

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*/

  This demo is based on the GD32E103V-EVAL-V1.0 board, it shows how to store user data 
in the backup data registers. Because the backup domain is still powered by VBAT 
when VDD is switched off, its contents will not be lost if a battery is connected 
to the VBAT pin.

  After every power-down and power-up operation, it checks whether value in the 
backup data registers is correct or not. If yes, LED2 is on, otherwise LED3 is on.

  Condition 1: Connect JP0 to Vmcu(+3v3). LED3 will be on when the board is powered up. 
Then execute a power-down and power-up operation, the light which is on is still LED3.

  Condition 2: Install a battery in BT1 and change JP0 connected to Vbat before the 
board is powered up. LED3 will be on when the board is powered up. Then execute a 
power-down and power-up operation, the light which is on will be LED2.

  BT1 should have a 3.3V battery, JP0 can change the VBAT source.  
