TMS320F280023C: Problems with ADC setup

Hi,

I have set up SOC2 on my microcontroller to trigger on the ePWM1 SOCA output signal.

There is a varying voltage on my input pin (A2), but despite the ISR being entered frequently (checked with a counter variable) the value of the ADC result register doesn't change. It just stays fixed at 2045-2046.

Here is my initialisation code and ISR code. Please help me figure out what I'm missing.

void init_adc(void)
{
    EALLOW;
    CpuSysRegs.PCLKCR13.bit.ADC_A=1;
    EDIS;
    ADC_setVREF(ADCA_BASE, ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V);

    EALLOW;
    AdcaRegs.ADCCTL1.bit.ADCPWDNZ=1;        // Power on the ADC

    AdcaRegs.ADCCTL2.bit.PRESCALE = 2;      // ADCCLK=50MHz for SYSCLK=100MHz

    //SOC2: triggered by EPWM1-SOCA, 270ns acquisition window, sampling on channel 2
    AdcaRegs.ADCSOC2CTL.bit.TRIGSEL = 0x5;
    AdcaRegs.ADCSOC2CTL.bit.ACQPS = 26;
    AdcaRegs.ADCSOC2CTL.bit.CHSEL = 2;

    AdcaRegs.ADCCTL1.bit.INTPULSEPOS=1;     // Interrupt pulse generation occurs at the end of conversion, 1 cycle before result latching on to the result reg
    AdcaRegs.ADCINTSEL1N2.bit.INT2SEL=2;    // Set EOC2 as interrupt trigger for ADCINT2
    AdcaRegs.ADCINTSEL1N2.bit.INT2CONT=0;
    AdcaRegs.ADCINTSEL1N2.bit.INT2E=1;
    EDIS;

    DEVICE_DELAY_US(5000);
}

__interrupt void ADC2_ISR(void)
{
    adcval_raw = AdcaResultRegs.ADCRESULT2;
    adcval = 3.3*(((float)adcval_raw)/4096);
    soaCurrent = ((1.65-adcval)/(20*0.004));
    EPwm1Regs.ETCLR.bit.SOCA=1;
    AdcaRegs.ADCINTFLGCLR.bit.ADCINT2=1;
    PieCtrlRegs.PIEACK.bit.ACK10=1;
}

Thanks in advance.

Regards,

Vishnu