F5528 DCO频率输出24000，代码如下：
#define UCS_MCLK_DESIRED_FREQUENCY_IN_KHZ 24000
#define UCS_MCLK_FLLREF_RATIO 732
//Set Ratio and Desired MCLK Frequency and initialize DCO
UCS_initFLLSettle(
UCS_MCLK_DESIRED_FREQUENCY_IN_KHZ,
UCS_MCLK_FLLREF_RATIO
);
调用UCS_initFLLSettle MCU会重启，这个是什么原因？ 按理5528是支持最大25MHz
