TM4C123G ADC digital comparator didn't work

I am stuck on digital comparator for couple days. I need some help..... The system has 4 analog inputs with timer trigger for ADC. An interrupt is triggered after ADC finished. One of anlogy input also sent to digital comparator. If the input value is higher than some value, then make count. The ADC and interrupt work good, but the digital comparator int status not right (or not triggered). I check the comparator int staus in the interrupt. Below is the code for ADC initial and interrupt. 

#define ADC_CTL_CT      ADC_CTL_CH15
#define ADC_CTL_PT      ADC_CTL_CH14
#define ADC_CTL_IN1     ADC_CTL_CH13
#define ADC_CTL_IN2     ADC_CTL_CH12

void
InitADC()
{
SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC1);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER2);
ADCHardwareOversampleConfigure(ADC1_BASE, 2);

GPIOPinTypeADC(GPIO_PORTD_BASE,GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);

ADCSequenceDisable(ADC1_BASE,0);
ADCSequenceConfigure(ADC1_BASE, 0, ADC_TRIGGER_TIMER, 0);
ADCSequenceStepConfigure(ADC1_BASE, 0, 0, ADC_CTL_CT|ADC_CTL_CMP0);
ADCSequenceStepConfigure(ADC1_BASE, 0, 1, ADC_CTL_CT);
ADCSequenceStepConfigure(ADC1_BASE, 0, 2, ADC_CTL_PT);
ADCSequenceStepConfigure(ADC1_BASE, 0, 3, ADC_CTL_IN1);
ADCSequenceStepConfigure(ADC1_BASE, 0, 4, ADC_CTL_IN2 | ADC_CTL_END | ADC_CTL_IE);

ADCSequenceEnable(ADC1_BASE, 0);

ADCComparatorConfigure(ADC1_BASE,0,ADC_COMP_TRIG_NONE|ADC_COMP_INT_HIGH_HONCE);
ADCComparatorRegionSet(ADC1_BASE, 0, 2100, 2200);
ADCComparatorReset(ADC1_BASE, 0, true, true);
ADCComparatorIntEnable(ADC1_BASE,0);

ADCIntEnable(ADC1_BASE, 0);
IntEnable(INT_ADC1SS0);

//set timer for adc1 converter trigger 50us
TimerConfigure(TIMER2_BASE, (TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_PERIODIC | TIMER_CFG_B_PERIODIC));
TimerLoadSet(TIMER2_BASE, TIMER_A, (SysCtlClockGet() * ADCTIMERPERIOD) - 1);
TimerControlTrigger(TIMER2_BASE, TIMER_A, true);
TimerEnable(TIMER2_BASE, TIMER_A);

}

uint32_t g_ui32ADC1Result[5];

//
void
ADC1IntHandler()
{

uint32_t ui32ComINTFlag;
static uint8_t ui8NumCycle=0;

ADCIntClear(ADC1_BASE, 0);

ADCSequenceDataGet(ADC1_BASE, 0, g_ui32ADC1Result);

ui32ComINTFlag=ADCComparatorIntStatus(ADC1_BASE);   //The comparatorInt status always zero ?????

if(ui32ComINTFlag!=0) 
{
ADCComparatorIntClear(ADC1_BASE, ui32ComINTFlag);
ui8NumCycle++;
}

}