spwm.c

本程序通过F2812实现SPWM,开发平台CCS

#include "DSP281x_Device.h"     // DSP281x Headerfile Include File
#include "DSP281x_Examples.h"   // DSP281x Examples Include File
#include "float.h"
#include "math.h"	
volatile unsigned int *Dataram_copy, *Dataram=(unsigned int*)0x100000;//RAM 起始地址为0X100000
volatile double sindata,angel,quzheng;   /*k代表角度*/
volatile unsigned int dotval1,half_period,currfreq,currampl,quad_period,flag,sinzh;
volatile unsigned long numdiv;
volatile unsigned long i,angel_step=0;

//Gpio 初始化
void Init_Gpio(void)
{EALLOW;
 GpioMuxRegs.GPAMUX.all=0x0003;//pwm0 1
 GpioMuxRegs.GPADIR.all=0x0003;//OUT
 GpioMuxRegs.GPDMUX.all=0x0000;//state
 GpioMuxRegs.GPADIR.all=0x0000;
 EDIS;
}
//EVA 初始化
void Init_EVA(void)
{/*T1 time 比较输出*/
 EvaRegs.GPTCONA.all=0xe065;
 EvaRegs.T1CNT=0;
 EvaRegs.T1PR=4095;
 EvaRegs.ACTRA.all=0x0556;//比较方式控制
 EvaRegs.DBTCONA.all=0x0f35;//死区1us
 EvaRegs.CMPR1=2048;
 EvaRegs.COMCONA.all=0x4b00;
 EvaRegs.COMCONA.all=0xcb00;//使能比较
 
 //EvaRegs.T1CON.all=0x104a;
 /*T4 time 周期采样*/
 EvbRegs.GPTCONB.all=0x0005;
 EvbRegs.T4PR=299;
 EvbRegs.T4CNT=0;
 EvbRegs.EVBIFRB.all=0x00ff;//清除标志
 //EvbRegs.T4CON.all=0x1042;//start T4
}


void main(void)
{
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP281x_SysCtrl.c file.
   InitSysCtrl();
   EALLOW;
   SysCtrlRegs.HISPCP.all = 0x0000;
   SysCtrlRegs.PCLKCR.bit.EVAENCLK=1;
   EDIS;

// Step 2. Initalize GPIO: 
// This example function is found in the DSP281x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
   Init_Gpio();  // Skipped for this example  

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

// Initialize 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 DSP281x_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 DSP281x_DefaultIsr.c.
// This function is found in DSP281x_PieVect.c.
   InitPieVectTable();
   
   for(i=0;i<=250000;i++)// Dataram<(Uint16*)0x107a13)//256K
    {angel=90.0/250000;//四分之一周期
     angel=angel*angel_step;
     angel=3.1415926*angel;
     angel=angel/180;/*数据类型优先级,sin弧度计算*/
     sindata=sin(angel);
     sindata=sindata*1024;
     sindata=sindata+1024;
     sindata=sindata*32;
     sinzh=sindata;
     quzheng=sindata-sinzh;
     if(quzheng>=0.5)
        sindata=sinzh+1;
     else
        sindata=sinzh;
     if(sindata>=65536)
       {*Dataram++=65535;
        angel_step++;
       }
     else 
       {*Dataram++=sindata;
        angel_step++;
       }
    }
 Init_EVA();
 EvbRegs.T4CON.all=0x1042;//start T4
 EvaRegs.T1CON.all=0x1048;
 asm(" clrc intm");
    
//PWM循环输出 
        Dataram=(unsigned int*)0x100000; 
        dotval1=32768; 
        half_period=0; //0为起点,1则过半周期
        currfreq=400;
        currampl=600;
        quad_period=0;// 0为起点,1则过1/4周期
        flag=1;//1:正前1/4周期；2:正后1/4周期; 3：负前1/4周期 ；4：负后1/4周期
CALVIB:
        //EvaRegs.CMPR1=0x0;
      switch(flag)
      
        {case 1:quad_period=0;half_period=0;break;
         case 2:quad_period=1;half_period=0;break;
         case 3:quad_period=0;half_period=1;break;
         case 4:quad_period=1;half_period=1;break;
         default: quad_period=0;half_period=0;break;
        }
        
        dotval1=*Dataram;
        dotval1=dotval1>>4;
       if(dotval1<0x800)//最小保护
            dotval1=0x800;	
        dotval1=dotval1-0x800;
        numdiv=currampl*dotval1;
        dotval1=numdiv>>10;
       if(dotval1>0x7ff)//最大保护
            dotval1=0x7ff;
            dotval1=dotval1+0x800;	//和T1PR=2048比较输出			
       if(half_period!=0)
        {   dotval1=0x1000-dotval1;
            dotval1++;
    	}
WAITT4:   
        if(!(EvbRegs.EVBIFRB.all&0x1))
            goto WAITT4; 		
        EvaRegs.CMPR1=dotval1;
          
       if(quad_period==1)
          Dataram=Dataram-currfreq;
                   
       else
          Dataram=Dataram+currfreq;
          
          Dataram_copy=Dataram;
          	
          EvbRegs.EVBIMRB.all=0x0; //禁止周期中断
        
        
        if((Dataram>=(unsigned int*)0x13d090)&&(half_period==0)&&(quad_period==0))//半周期,250000=224K
           {flag=2;//过1/4周期
            Dataram=(unsigned int*)0x13d090;
           }
        if((Dataram<=(unsigned int*)0x100000)&&(half_period==0)&&(quad_period==1))
           {flag=3;
            Dataram=(unsigned int*)0x100000;
           }
        if((Dataram>=(unsigned int*)0x13d090)&&(half_period==1)&&(quad_period==0))
           {flag=4;
            Dataram=(unsigned int*)0x13d090;
           }
        if((Dataram<=(unsigned int*)0x100000)&&(quad_period==1)&&(half_period==1))
           {flag=1;
            Dataram=(unsigned int*)0x100000;
            }

          
//一点结束

        EvbRegs.EVBIFRB.all=0x0ff;
        EvbRegs.EVBIMRB.all=0x0ff;//start 
        goto CALVIB;
}
//===========================================================================
// No more.
//=====