pwm_m.c

F2812上实现正弦脉宽调制,里边有通过编译的头文件

#include "DSP28_Device.h"
#include "stdio.h"
#include "math.h"
#include "float.h"
#define NX 404
#define PI 3.1415925
float M=0.8;
int k0,h1,h2;
double a[NX];
extern int  tp = 1250;

void zkb();
interrupt void eva_T1UFINT_ISR(void);

void main(void){   

    k0 = 0;
    h1 = 0;
    h2 = 0;
    InitSysCtrl();
    DINT;   //禁止全局中断
    IER=0;
    IFR=0;    
    EALLOW;
    // Enable PWM pins
    GpioMuxRegs.GPAMUX.all = 0x00FF; // EVA PWM 1-6  pins
    // GpioMuxRegs.GPBMUX.all = 0x00FF; // EVB PWM 7-12 pins
    EDIS;   
    InitPieCtrl();
    InitPieVectTable();    
    EALLOW;
    PieVectTable.T1UFINT=&eva_T1UFINT_ISR;
    EDIS;    
    IER|=M_INT2;
    PieCtrl.PIEIER2.bit.INTx6=1;   
    InitEv();
    zkb();           
    EvaRegs.T1CON.all=EvaRegs.T1CON.all|0x0040;  //启动定时器1
    EINT;
    while(1)
     {
        asm("NOP");
     }
       }	
void zkb()
{
  unsigned int n=0;        
  float q,l,j;
  while (n<=NX)         
  {
    q=(n+0.75);    //为消除偶次偕波，减少谐波角度出发，选择从A相3/4周期进行采样
    q=q*2*PI;      
    q/=405; 
    j=sin(q);      
    l=0.5*tp*(1+M*j);//M为调制比     //计算占空比表达式   
 /* l=1875*(1+M*j);//M为调制比     //计算占空比表达式
    if(l>=375&&l<=3375)
       a[n]=l;  
     else
        {
       if(l>3375)
         a[n]=3375;
       else
       a[n]=375;
       }  
     
     n=n+1;
 */
     if((l>=(tp*0.1))&&(l<=(tp*0.9)))
      a[n]=l; 
       else
        {
       if(l>(tp*0.9))
         a[n]=tp*0.9;
       else
       a[n]=tp*0.1;
       }  
     
     n=n+1;
       }
}
interrupt void eva_T1UFINT_ISR(void)    // EV-A
{
  int h2;
  int flag;
  flag=(EvaRegs.EVAIFRA.all) & 0x0200;  //T1UFINT中下益中断标志位置1 
        if(flag!=0x0200) 
            {
           EINT;
           return;
             } 
        else
         {
           if(k0<=NX)
          {
           h1=k0+135;      //B相表达式
            if(h1>=404)
              h1=h1-404;
              h2=k0+270;   //C相表达式
             if(h2>=404)
              h2=h2-404;
           EvaRegs.CMPR1=a[k0];
           EvaRegs.CMPR2=a[h1];                                                                                                                                                                            
           EvaRegs.CMPR3=a[h2]; 
           k0=k0+1;
           }
          else       
           {
             k0=0; 
           }
          }
  
    EvaRegs.EVAIMRA.bit.T1UFINT=1;
    EvaRegs.EVAIFRA.bit.T1UFINT=1;
    PieCtrl.PIEACK.all=0x0002;
    EINT;                       //开全局中断

    
}


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// No more.
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