此程序为KEIL环境下开发的代码（开发环境备选里没有KEIL），功能在成功运行后可以播放“生日快乐”歌。所需要的开发硬件为AT89C51为主芯片的单片机。-This program is developed under the code in KEIL environment (development environment, where there is no alternative KEIL), features a successful running play " Happy Birthday"　song. Required the development of hardware-based chip microcontroller AT89C51.