TMS320F28377D: 28377d时钟问题

我用一个系统用的是28377D芯片，使用外部有源晶振20Mhz但使用driverlib.lib例程点亮led等程序一直死在时钟设置

static void
SysCtl_pollCpuTimer(void)
{
uint16_t loopCount = 0U;

//
// Delay for 1 ms while the XTAL powers up
//
// 2000 loops, 5 cycles per loop + 9 cycles overhead = 10009 cycles
//
SysCtl_delay(2000);

//
// Clear and overflow cpu timer 2 4x to guarantee operation
//
do
{
//
// Wait for cpu timer 2 to overflow
//
while(CPUTimer_getTimerOverflowStatus(CPUTIMER2_BASE)==false);
{
//
// If your application is stuck in this loop, please check if the
// input clock source is valid.
//
}

//
// Clear cpu timer 2 overflow flag
//
CPUTimer_clearOverflowFlag(CPUTIMER2_BASE);

//
// Increment the counter
//
loopCount++;

}while(loopCount < 4U);
}

函数内。

时钟配置如下

#define DEVICE_OSCSRC_FREQ 20000000U

//
// Define to pass to SysCtl_setClock(). Will configure the clock as follows:
// PLLSYSCLK = 20MHz (XTAL_OSC) * 20 (IMULT) * 1 (FMULT) / 2 (PLLCLK_BY_2)
//
#define DEVICE_SETCLOCK_CFG (SYSCTL_OSCSRC_XTAL | SYSCTL_IMULT(20) | \
SYSCTL_FMULT_NONE | SYSCTL_SYSDIV(2) | \
SYSCTL_PLL_ENABLE)

//
// 200MHz SYSCLK frequency based on the above DEVICE_SETCLOCK_CFG. Update the
// code below if a different clock configuration is used!
//
#define DEVICE_SYSCLK_FREQ ((DEVICE_OSCSRC_FREQ * 20 * 1) / 2)

请问ti工程师还有没有别的情况会死在这个函数的循环内