/**
  **************************************************************************
  * @file     readme.txt
  * @brief    readme
  **************************************************************************
  */

  this demo is based on the ht32f49163_sk board, in this demo, shows how to
  use PVM to write the saved data in time when power down.
  --led4 on               : code running
  --led2 on and led3 off  : data is successfully saved
  --led2 off and led3 on  : no data being saved or data saved fail
