/* The function is used to set HCLK clock source.  */
void SysCtlHCLKSourceSet(unsigned long ulHclkSrcSel)
/* The function is used to set HCLK clock source.  */
void SysCtlHCLKSourceSet(unsigned long ulHclkSrcSel)
{
    unsigned long ulRegValue;
	xASSERT((ulEnable == SYSCTL_HLCK_S_INT48M) ||
    		(ulEnable == SYSCTL_HLCK_S_EXT32K) ||
    		(ulEnable == SYSCTL_HLCK_S_INT16K));
    SysCtlKeyAddrUnlock();
    ulRegValue = xHWREG(SYSCLK_CLKSEL0);
    ulRegValue &= ~SYSCLK_CLKSEL0_HCLK_S_M;
    ulRegValue |= ulHclkSrcSel;
    xHWREG(SYSCLK_CLKSEL0) = ulRegValue;
    SysCtlKeyAddrLock();
}