请问ccs3.3里面程序运行到 asm（“ NOP”）就不动了是怎么回事？

main()
{

InitSysCtrl();

EALLOW;
SysCtrlRegs.HISPCP.all = ADC_MODCLK; // HSPCLK = SYSCLKOUT/ADC_MODCLK
EDIS;

InitEPwm1Gpio();

InitEPwm2Gpio();
InitEPwm3Gpio();

InitEPwm4Gpio();

InitAdc(); 
DINT;

InitPieCtrl();

IER = 0x0000;
IFR = 0x0000;

InitPieVectTable();

PieVectTable.ADCINT = &adc_isr;
PieVectTable.EPWM1_INT = &epwm1_isr;
EDIS; // This is needed to disable write to EALLOW protected registers

InitPower_cal();

DataClear();

EALLOW;
GpioCtrlRegs.GPAMUX2.bit.GPIO25 = 0; // GPIO0 = GPIO0
GpioCtrlRegs.GPADIR.bit.GPIO25 = 1;
EDIS;
GpioDataRegs.GPADAT.bit.GPIO25 = 1;

EALLOW; 
PieVectTable.ADCINT = &adc_isr;
PieVectTable.EPWM1_INT = &epwm1_isr;
EDIS; 

InitEPwm1Example();
GpioCtrlRegs.GPAMUX2.bit.GPIO25 = 0; 
GpioCtrlRegs.GPADIR.bit.GPIO25 = 1;
GpioDataRegs.GPADAT.bit.GPIO25 = 0;//////////////////0闭合继电器

EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
EDIS;

// Enable EPWM INTn in the PIE: Group 3 interrupt 1-3
PieCtrlRegs.PIEIER3.bit.INTx1 = 1;
// Enable ADCINT in PIE
PieCtrlRegs.PIEIER1.bit.INTx6 = 1;
IER |= M_INT1; // Enable CPU Interrupt 1
// Enable CPU INT3 which is connected to EPWM1-3 INT:
IER |= M_INT3;

/* EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
EDIS;
*/
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM

for(;;)
{
asm(" NOP");
}
}

程序就指向asm(" NOP"); 不知道是怎么回事？这是正常的吗？我想让它进中断，可是进不去。