RM57LX how to setup eQEP edge capture unit

QCTMRLAT and QCPRDLAT register(or any other) don't have any value show up when reading quadrature signal in eQEP1A and eQEP1B.

I have enable eQEP Peripherals in PINMUX ,and have set EQEP1  Position Counter mode in QUADRATURE_COUNT, nothing work.

Main function:

void main(void)
{
/* USER CODE BEGIN (3) */
	uint16 period, timer, status;

	QEPInit();
	eqepEnableCapture(eqepREG1);
	eqepEnableCounter(eqepREG1);
	eqepSetCaptureLatchMode(eqepREG1,QEPCTL_Qclm_Latch_on_CPU_Read);
	eqepSetUnitPosnPrescale(eqepREG1,QCAPCTL_Upps_Div_2_Prescale); //QCAPCTL[UPPS] = 0010, Enable edge capture unit
	eqepSetCapturePrescale(eqepREG1,QCAPCTL_Ccps_Capture_Div_128);

	while(1)
	{
		timer = eqepReadCaptureTimerLatch(eqepREG1);
		period = eqepReadCapturePeriodLatch(eqepREG1);
		status = eqepReadStatus(eqepREG1);
		eqepREG1->QEPSTS |= (1 << 7);
		if((status >> 7) & 0x01 )	//QEPSTS:UPEVNT  = 1, unit position event detected
		{
			eqepReadPosnCount(eqepREG1);	//Latch value into QCTMRLAT and QCPRDLAT
			eqepREG1->QEPSTS |= (1 << 7);	//write 1 to clear QEPSTS:UPEVNT
		}


	}
/* USER CODE END */
}