这是msp430f449单片机系统时钟源控制和选择的控制方式源代码，可以选择片外高速晶振，片外标准时钟晶振，片内RC振荡器三个时钟源-This is the MSP430F449 single-chip system clock source control and choice of source code control, you can choose high-speed chip oscillator, standards-ch