TM4C123GH6PM's ADC become abnormal while activate its PWM function

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/sysctl.h"
#include "driverlib/adc.h"
#define TARGET_IS_BLIZZARD_RB1
#include "driverlib/rom.h"
#include "driverlib/sysctl.h"
#include "driverlib/pin_map.h"
#include "driverlib/gpio.h"
#include "driverlib/pwm.h"

int main(void)
{
	//create array for storing data read from ADC FIFO
	uint32_t ui32ADC0Value[4];
	volatile uint32_t ui32TempAvg;
	volatile uint32_t ui32TempValueC;
	volatile uint32_t ui32TempValueF;
	volatile uint32_t ui32Load;

	//enable clock
	ROM_SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);

	//TEST Enable GPIO
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
	GPIOPinTypeADC(GPIO_PORTD_BASE,GPIO_PIN_1);	//Configure PD0 as ADC

	//enable adc peripheral
	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);

	//average the sample, 64 means take 64 samples and do averaging, so total sampling time will be 64 *4
	ROM_ADCHardwareOversampleConfigure(ADC0_BASE, 64);

	//reprogramming sampling rate (pending)

	//configure ADC sequencer, sample sequencer 1, processor triggered sequence with highest priority
	ROM_ADCSequenceConfigure(ADC0_BASE, 1, ADC_TRIGGER_PROCESSOR, 0);

	//configure all four steps in the ADC sequencer, last sequencer require extra setting (ADC_CTL_LE for setting interrupt flag, ADC_CTL_END tell ADC is last)
	ROM_ADCSequenceStepConfigure(ADC0_BASE, 1, 0, ADC_CTL_CH6);
	ROM_ADCSequenceStepConfigure(ADC0_BASE, 1, 1, ADC_CTL_CH6);
	ROM_ADCSequenceStepConfigure(ADC0_BASE, 1, 2, ADC_CTL_CH6);
	ROM_ADCSequenceStepConfigure(ADC0_BASE, 1, 3, ADC_CTL_CH6|ADC_CTL_IE|ADC_CTL_END);

	//enable ADC sequencer 1
	ADCSequenceEnable(ADC0_BASE, 1);

/*	// Initialise PB7 M0PWM1
	ROM_SysCtlPWMClockSet(SYSCTL_PWMDIV_1);				// clock defined in sysctl.c
	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM0);		// TM4C123GH6PM has two modules (0 and 1)
	ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
	ROM_GPIOPinTypePWM(GPIO_PORTB_BASE, GPIO_PIN_7);
	GPIOPinConfigure(GPIO_PB7_M0PWM1);

	ROM_PWMGenConfigure(PWM0_BASE, PWM_GEN_0, PWM_GEN_MODE_UP_DOWN | PWM_GEN_MODE_NO_SYNC);
	ui32Load = (ROM_SysCtlClockGet() / 25000) - 1;
	ROM_PWMGenPeriodSet(PWM0_BASE, PWM_GEN_0, ui32Load);
	ROM_PWMPulseWidthSet(PWM0_BASE, PWM_OUT_1, 900);
	ROM_PWMOutputState(PWM0_BASE, PWM_OUT_1_BIT, true);
	ROM_PWMGenEnable(PWM0_BASE, PWM_GEN_0);
*/

	while(1)
	{
		//clear interrupt
		ROM_ADCIntClear(ADC0_BASE, 1);
		ROM_ADCProcessorTrigger(ADC0_BASE, 1);

		//wait the conversion to complete
		while(!ROM_ADCIntStatus(ADC0_BASE, 1, false)){}

		//after conversion done, start reading out the sequencer FIFO
		ROM_ADCSequenceDataGet(ADC0_BASE, 1, ui32ADC0Value);

		//do averaging, 2 for rounding issue
		ui32TempAvg = (ui32ADC0Value[0] + ui32ADC0Value[1] + ui32ADC0Value[2] + ui32ADC0Value[3] + 2) / 4;

/*		//do conversion from Celsius to Farenheit
		ui32TempValueC = (1475 - ((2475 * ui32TempAvg))/ 4096 )/10;

		ui32TempValueF = ((ui32TempValueC *9) +160)/5;
*/


	}


}