新手在学习28335的ADC模块中遇到的问题

买得研旭的板子，跟着手把手教学那本书在学，现在学到了ADC模块，根据研旭给的例程，对其中ADC模块产生中断的原理不懂，具体如下：（红色为我标记不懂的地方，其他颜色为例程程序）

#include "DSP2833x_Device.h"     // DSP2833x Headerfile Include File
#include "DSP2833x_Examples.h"   // DSP2833x Examples Include File

// Determine when the shift to right justify the data takes place
// Only one of these should be defined as 1.
// The other two should be defined as 0.
#define POST_SHIFT   0  // Shift results after the entire sample table is full
#define INLINE_SHIFT 1  // Shift results as the data is taken from the results regsiter
#define NO_SHIFT     0  // Do not shift the results

// ADC start parameters
#if (CPU_FRQ_150MHZ)     // Default - 150 MHz SYSCLKOUT
  #define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3)   = 25.0 MHz
#endif
#if (CPU_FRQ_100MHZ)
  #define ADC_MODCLK 0x2 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2)   = 25.0 MHz
#endif
#define ADC_CKPS   0x0   // ADC module clock = HSPCLK/1      = 25.5MHz/(1)   = 25.0 MHz
#define ADC_SHCLK  0x1   // S/H width in ADC module periods                  = 2 ADC cycle
#define AVG        1000  // Average sample limit
#define ZOFFSET    0x00  // Average Zero offset
#define BUF_SIZE   512  // Sample buffer size

// Global variable for this example
Uint16 SampleTable[BUF_SIZE];

main()
{
   Uint16 i;
   Uint16 array_index=0;

   InitSysCtrl();

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

   DINT;

   InitPieCtrl();

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

   InitPieVectTable();

   InitAdc();         // For this example, init the ADC

// Specific ADC setup for this example:
   AdcRegs.ADCTRL1.bit.ACQ_PS = ADC_SHCLK;  // Sequential mode: Sample rate   = 1/[(2+ACQ_PS)*ADC clock in ns]
                        //                     = 1/(3*40ns) =8.3MHz (for 150 MHz SYSCLKOUT)
                                            //                     = 1/(3*80ns) =4.17MHz (for 100 MHz SYSCLKOUT)
                                            // If Simultaneous mode enabled: Sample rate = 1/[(3+ACQ_PS)*ADC clock in ns]
   AdcRegs.ADCTRL3.bit.ADCCLKPS = ADC_CKPS;
   AdcRegs.ADCTRL1.bit.SEQ_CASC = 1;        // 1  Cascaded mode
   AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x1;
   AdcRegs.ADCTRL1.bit.CONT_RUN = 1;       // Setup continuous run

   AdcRegs.ADCTRL1.bit.SEQ_OVRD = 1;       // Enable Sequencer override feature
   AdcRegs.ADCCHSELSEQ1.all = 0x0;         // Initialize all ADC channel selects to A0
   AdcRegs.ADCCHSELSEQ2.all = 0x0;
   AdcRegs.ADCCHSELSEQ3.all = 0x0;
   AdcRegs.ADCCHSELSEQ4.all = 0x0;
   AdcRegs.ADCMAXCONV.bit.MAX_CONV1 = 0x1;  // convert and store in 8 results registers



// Clear SampleTable
   for (i=0; i    {
     SampleTable = 0;

   }


// Start SEQ1
   AdcRegs.ADCTRL2.all = 0x2000;这么写值，并没有使能SEQ1或SEQ2的中断，难道是例程错了吗？

        while(1)
        {
        //        array_index = 0;
                while(AdcRegs.ADCST.bit.INT_SEQ1 == 0);上面没有开中断，那么这里查询中断标志就没意义啊。
        //        GpioDataRegs.GPBSET.bit.GPIO34 = 1;  // Set GPIO34 for monitoring  -optional
                AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1;
                SampleTable[array_index++]= ( (AdcRegs.ADCRESULT0)>>4);
                if(array_index>(BUF_SIZE-1)) array_index=0;
                DELAY_US(100);
                GpioDataRegs.GPBCLEAR.bit.GPIO34 = 1;  // Clear GPIO34 for monitoring  -optional
         }

}

//===========================================================================
// No more.
//===========================================================================
感谢各位解答！！

0