spwm3.c

TMS320F2812的SPWM原程序,不明白的地方请与我联系!

 //实现了SPWM的输出
#include "DSP281x_Device.h"
#include "stdio.h"
#include "math.h"
#include "float.h"
#define NX 404
#define PI 3.1415925
float M=0.8;
int k0=0,h1=0;
double a[NX];
void zkb();
interrupt void eva_T1UFINT_ISR(void);
 unsigned int n=0; 
  float q,l,j;
void main(void)
{
    InitSysCtrl(); //系统初始化
    DINT;         //禁止全局中断
    IER=0x0000;
    IFR=0x0000;
    
    EALLOW;     
    GpioMuxRegs.GPAMUX.all = 0x00FF; // EVA PWM 1-6  pins
    EDIS;
   
    InitPieCtrl();     
    InitPieVectTable();
    
    EALLOW;        //使能定时器1下益中断
    PieVectTable.T1UFINT=&eva_T1UFINT_ISR;
    EDIS;
    
    IER|=M_INT2;  //开中断2
    PieCtrlRegs.PIEIER2.bit.INTx6=1; //开下益中断
  
////////////////////
 
  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=1875*(1+M*j);//M为调制比     //计算占空比表达式
    //if(l>=187&l<=1687)(此处网友设置为错误的）
   if(l>=375&l<=3375)
     a[n]=l;  
    else
        {
        if(l>3375)
         a[n]=3375;
        else
         a[n]=375;
        }  
     
   n=n+1;
  }
//////////////////////////////
  
    
  ///init_eva
///////////////////////////////
 EvaRegs.ACTRA.all=0x0666;
 EvaRegs.DBTCONA.all = 0x0000;  // Disable deadband
 EvaRegs.COMCONA.all = 0xa600;  //使能比较操作

 EvaRegs.EVAIMRA.all=0x0200; //EVAIMRA(EVA的中断屏蔽寄存器A).T1UIINT(通用定时器1的下溢中断使能)
 EvaRegs.EVAIMRB.all=0x0000;
 EvaRegs.EVAIMRC.all=0x0000;
 EvaRegs.EVAIFRA.all=0xffff;//EVAIFRA(EVA的中断标志寄存器.T1UIINT(通用定时器1的下溢中断标志)
 EvaRegs.EVAIFRB.all=0xffff;//写1清除定时器1的下溢中断标志
 EvaRegs.EVAIFRC.all=0xffff;                             
 EvaRegs.CMPR1=0;           //初始化寄存器的值
 EvaRegs.CMPR2=0;
 EvaRegs.CMPR3=0;        
 
 EvaRegs.GPTCONA.all=0x0041;
    //周期必须大于最大的正弦表格值
 EvaRegs.T1PR = 3750;       // Timer1 period PWM载波周期为 65536个定标的定时器时钟周期 
 //EvaRegs.T1PR = 0xffff;
 //EvaRegs.T1CNT = 937;      // Timer1 counter 
 EvaRegs.T1CNT = 937;
 //EvaRegs.T1CON.all = 0x0b4e;  // 选择模式产生PWM波10
 
 EvaRegs.T1CON.all = 0x0b4e;
 EINT;
 
 
 
 return;
///////////////////////////
  EvaRegs.T1CON.all=EvaRegs.T1CON.all|0x0040;  //启动定时器1
  
      
           for(;;);  
} 

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];  //更新比较寄存器2的值                                                                                                                                                                          
       EvaRegs.CMPR3=a[h2];  //更新比较寄存器3的值
       k0=k0+1;
       }
      else       
       {
        k0=0; 
       }
      }
  
    EvaRegs.EVAIMRA.bit.T1UFINT=1; //清除中断屏蔽标志
    EvaRegs.EVAIFRA.bit.T1UFINT=1; //清楚中断使能标志
    PieCtrlRegs.PIEACK.all=0x0002;     //响应同组中断
    EINT;                          //开全局中断
}