/**
  **************************************************************************
  * @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, pc6-9 toggle each
  compare time.
  ch1 overflow rate = tmr2 counter clock / c1dt_val = 146.48 hz
  ch2 overflow rate = tmr2 counter clock / c2dt_val = 219.7 hz
  ch3 overflow rate = tmr2 counter clock / c3dt_val = 439.4 hz
  ch4 overflow rate = tmr2 counter clock / c4dt_val = 878.9 hz 
