在CCS环境下用C写的TI的msp430f6638的一个电子琴程序，按不同的按键时，改变频率，蜂鸣器发出不同的声音，并且可实现按一个键播放一段乐曲。-In the CCS environment written in C TI' s msp430f6638 an organ program, when you press a different key, change the frequency, the buzzer sounds different, and can be achiev