C6657 UART波特率

在SYSBIOS中调用UART driver进行UART通讯时，发现在PC端无法正常接收信息。用示波器检测发现波特率并不等于设置的115200，实际只有12500。主频率使用BIOS_setCpuFreq(&freq)设置成1000MHz。下面代码还需要初始化什么来匹配好波特率呢？

 char echoPrompt[] = "12345";

UART_init();

UART_Params_init(&params);
params.baudRate = 115200;
params.writeDataMode = UART_DATA_BINARY;
params.readDataMode = UART_DATA_BINARY;
params.readReturnMode = UART_RETURN_FULL;
params.readEcho = UART_ECHO_OFF;
uart_handle = UART_open(UART_INSTANCE, &params);
if (!uart_handle) {
System_printf("UART did not open");
}
int ret = UART_write(uart_handle,echoPrompt,sizeof(echoPrompt));
System_printf("The UART wrote %d bytes\n", ret);