该文档是介绍基于单片机的音乐盒设计，包括设计方案及程序。此音乐盒功能为：通过按键实现九首歌曲的上一首、下一首、暂停、停止、循环等功能。-This document is to introduce the music box design based on the sigle-chip, including the design  programs and procedures. This music box function:through exchange key to realiz