/**
  **************************************************************************
  * @file     readme.txt
  * @version  v2.0.0
  * @date     2021-11-26
  * @brief    readme
  **************************************************************************
  */

  this demo is based on the at-start board, in this demo, shows how to configure
  the tmr1 peripheral to a base interrupt. when systermclock/14400/10000 =
  1hz will generater overflow interrupt and toggle led3.
