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

  this demo is based on the ht32f49395_sk board, in this demo, show how to build
  a composite device device of usb audio class protocol and hid protocol. the codec use wm8988
  the demo support:
  1. microphone and speaker
  2. frequency 16k and 48k
  3. bit width 16bit
  4. speaker feedback
