DSP2808 ADC problem.

I have build a project (2808, CCS 5.5) for ADC based on a example project "Example_280xAdcSoc", key information are:

1. Dual-sequencer and Sequencing sampling mode, internal reference is activated.

2. CONV00~CONV04 five channels are used for conversion, corresponding regs ADCResult0~ADCResult5.

3. ePWM1 is set as the trigger for ADC conversion

4. connect the CONV00 to 3.3V and CONV01~CONV04 to GND.

The problem: I observed the data in ADCResult0~ADCResult4, and find that the values of ADCResult0 and ADCResult1 are same, and the values of ADCReslut2~ADCResult4 are same. This is very weird considering my connection (step 4). Moreover, ADCResult0 and ADCResult1 are 17872, ADCReslut2~ADCResult4 are 13880. Because I do not know the value of the internal reference (step 1), I do not know whether  the results is right or not. Maybe this is because of my codes, anyone can help me?

The customized codes are listed as follows:

#include "DSP280x_Device.h"       // DSP280x Headerfile Include File
#include "DSP280x_Examples.h"     // DSP280x Examples Include File
#include "Customized_Function.h"  // Customized Function

// Prototype statements for functions found within this file.
interrupt void adc_isr(void);

// Global variables used in this example:
int Voltage[5];
int Flag;

main()
{
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP280x_SysCtrl.c file.
   InitSysCtrl();

// For this example, set HSPCLK to SYSCLKOUT / 8 (12.5Mhz assuming 100Mhz SYSCLKOUT or 7.5 MHz assuming 60 MHz SYSCLKOUT)
   EALLOW;
   SysCtrlRegs.HISPCP.all = 0x0000;  // HSPCLK = SYSCLKOUT/8
   EDIS;

// Step 2. Initialize GPIO:
// InitGpio();  // Skipped for this example

// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
   DINT;

// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP280x_PieCtrl.c file.
   InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:
   IER = 0x0000;
   IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in DSP280x_DefaultIsr.c.
// This function is found in DSP280x_PieVect.c.
   InitPieVectTable();

// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
   EALLOW;  // This is needed to write to EALLOW protected register
   PieVectTable.ADCINT = &adc_isr;
   EDIS;    // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP280x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
   InitAdc();  // For this example, init the ADC

// Step 5. User specific code, enable interrupts:

// Enable ADCINT in PIE
   PieCtrlRegs.PIEIER1.bit.INTx6 = 1;
   IER |= M_INT1; // Enable CPU Interrupt 1
   EINT;          // Enable Global interrupt INTM
   ERTM;          // Enable Global realtime interrupt DBGM

// Configure ADC
   AdcRegs.ADCTRL1.bit.SEQ_CASC=0;        //setDual-sequencer mode
   AdcRegs.ADCTRL3.bit.SMODE_SEL=0;       //set Sequencing sampling mode
   AdcRegs.ADCREFSEL.bit.REF_SEL=0x00;    //reference select bit, 00 is internal bandgap reference
   AdcRegs.ADCTRL3.bit.ADCBGRFDN=0x03;    //power up the bandgap reference
   AdcRegs.ADCMAXCONV.all = 0x0004;       // Setup 5 conversions on SEQ1
   AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x0; // Setup ADCINA0 as 1st SEQ1 conv.
   AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x1; // Setup ADCINA1 as 2nd SEQ1 conv.
   AdcRegs.ADCCHSELSEQ1.bit.CONV02 = 0x2; // Setup ADCINA2 as 3rd SEQ1 conv.
   AdcRegs.ADCCHSELSEQ1.bit.CONV03 = 0x3; // Setup ADCINA3 as 4th SEQ1 conv.
   AdcRegs.ADCCHSELSEQ2.bit.CONV04 = 0x4; // Setup ADCINA4 as 5th SEQ1 conv.
   AdcRegs.ADCTRL2.bit.EPWM_SOCA_SEQ1 = 1;// Enable SOCA from ePWM to start SEQ1
   AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1;  // Enable SEQ1 interrupt (every EOS)

// Assumes ePWM1 clock is already enabled in InitSysCtrl();
   EPwm1Regs.ETSEL.bit.SOCAEN = 1;        // Enable SOC on A group, SOC means start of conversion
   EPwm1Regs.ETSEL.bit.SOCASEL = 4;       // Select SOC from CPMA on upcount
   EPwm1Regs.ETPS.bit.SOCAPRD = 1;        // Generate pulse on 1st event
   EPwm1Regs.CMPA.half.CMPA = 0x0000;	  // Set compare A value
   EPwm1Regs.TBPRD = 0x0001;              // Set period for ePWM1
   EPwm1Regs.TBCTL.bit.CTRMODE = 0;       // count up and start

// Wait for ADC interrupt

   for(;;)
   {
      if (FLAG==1)//customized codes
           {
      	      Customized_Function();//
             
              FLAG=0;

              // Reinitialize for next ADC sequence
              AdcRegs.ADCTRL2.bit.RST_SEQ1 = 1;         // Reset SEQ1
              AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1;       // Clear INT SEQ1 bit
              PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;   // Acknowledge interrupt to PIE
           }
   }
}


interrupt void  adc_isr(void)
{
  Voltage[0] = (((int)(AdcRegs.ADCRESULT0 >>4))*3)/4095;
  Voltage[1] = (((int)(AdcRegs.ADCRESULT1 >>4))*3)/4095;
  Voltage[2] = (((int)(AdcRegs.ADCRESULT2 >>4))*3)/4095;
  Voltage[3] = (((int)(AdcRegs.ADCRESULT3 >>4))*3)/4095;
  Voltage[4]= (((int)(AdcRegs.ADCRESULT4 >>4))*3)/4095;

  // Conversion finished, start over
  FLAG=1;

  return;
}