msp430f5438 uart串口波特率设置32768Hz,波特率19200

用32768Hz配置19200可能会有问题，实际上32768/3是波特率的最大值，在User Guider中也是在32768下的建议波特率最高到9600.

以下是摘自e2e论坛的回答

However, 32768/19200 is1.7, so the first bit would be 1/32768s, the next one 2/32768s, then again 1/32768s etc. The resulting bitlenght-error will be far, far beyond any acceptable limit.
With higher frequencies, the divider gets larger, and the difference between UCBR and UCBR+1 gets smaller, so the maximum bitrate error gets smaller. Or the baudrate can be higher. The maximum baudrate for the USCI is IMHO 1MBd. A faster clock source will not allow higher baudrates, only a higher divider and therefore a smaller error (if it isn't an exact multiple anyway). or allow the 16x overclocking

参照下表，32768不能设置19200的波特率，附件中有一个430波特率计算器使用很方便，只要输入频率和波特率就可以计算出来了。