F28335 ADC单通道单次采样 代码+注释

程序功能比较简单：主要在于配置 功能单通道的单次采样

1，CON0口采样

2，输出7位小数采样电压

#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   2  // Sample buffer size

// Global variable for this example
volatile Uint16 SampleTable[BUF_SIZE];
volatile float adc0=0;
main()
{
   Uint16 i;
  // Uint16 adc=0;
   Uint16 array_index;

   InitSysCtrl();

   EALLOW;
   SysCtrlRegs.HISPCP.all = ADC_MODCLK;	//  系统外设时钟6分频，一般ADC就用6分频
                                        //  这是因为ADC最高只能配置25MHz的频率
                                        //  所以最快转换一次的时间使80ns
   EDIS;


   DINT;

   InitPieCtrl();

   IER = 0x0000;
   IFR = 0x0000;

   InitPieVectTable();

   InitAdc();                                  //这个初始化程序，必须添加DSP2833x_Adc.C文件


   AdcRegs.ADCTRL1.bit.ACQ_PS = ADC_SHCLK;     //ADC采样时间选择
   AdcRegs.ADCTRL3.bit.ADCCLKPS = ADC_CKPS;    //ADC内核分频
   AdcRegs.ADCTRL1.bit.SEQ_CASC = 1;           //级联工作方式
   AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x1;      //设置CONV0 为第一个通道
   AdcRegs.ADCTRL1.bit.CONT_RUN = 0;           //连续运行模式

   AdcRegs.ADCTRL1.bit.SEQ_OVRD = 1;           //完成排序后，排序器指针回到最初状态
   AdcRegs.ADCCHSELSEQ1.all = 0x0;             //初始化SEQ1排序寄存器
   AdcRegs.ADCMAXCONV.bit.MAX_CONV1 = 0x0;     // 设置一对转换，共16通道



// Clear SampleTable
   for (i=0; i2)
		array_index = 0;


		while(AdcRegs.ADCST.bit.INT_SEQ1 == 0);                 //等待ADC的中断位为1


		AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1;                     //清楚排序器中断位

		SampleTable[array_index++]= ( (AdcRegs.ADCRESULT0)>>4); //将结果寄存器16位的值转换位10进制数

		adc0=(float)SampleTable[0] * 3.0 /4096.0;               // 转换为我们读取的数据类型
		                                                        // 数据类型转换另外一篇有说明



		DELAY_US(100);
	 }
  
}

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// No more.
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