pwm.c

该程序的功能是完成电机的PWM变换

/*************************************************
本程序通过2407的pwm单元产生占空比连续变化的pwm波形
**************************************************/
#include "register.h"
unsigned char i=0,direct=0;
int pwmval=0;

initsys()
{
  asm(" setc INTM ");
  asm(" setc SXM ");
  asm(" clrc OVM ");
  asm(" clrc CNF ");
  *SCSR1=0X82FE;  //CLKIN=10M,CLKOUT=2*CLKIN=20M
  *WDCR=0X0E8;
  *IMR=0X0002;
  *IFR=0X0FFFF;
   WSGR=0X00;        //禁止所有等待状态
  
}

int initpwm()
{
 *MCRA=*MCRA|0X0CC0;  //初始化IO口
 *ACTRA=*ACTRA|0X0606;/*PWM1,5高位有效,PWM2,6低位有效*/
                      
 *DBTCONA=0X0AA8;/*使能死区单元,(10*4)/CLKOUT=2us*/
             
 *T1CON=0X0800;    //定时器为连续增减计数模式
 *T1PER=1000;   /*设置Timer1的周期寄存器值，
                定时器周期为2*1000/CLKOUT=100us，对称输出方式*/
 
 *T1CNT=0x0000; 
              
 *CMPR1=0; 
 *CMPR3=0;                 
                  
 *COMCONA=0x8200;  //使能pwm
 
 *EVAIMRA=*EVAIMRA|0X0080;
 *EVAIFRA=*EVAIFRA|0X0080; //使能Timer1的周期中断和清除标志位

}
main()
{
   initsys();
   initpwm();
   *T1CON=*T1CON|0X0040;
   asm(" clrc INTM "); //******开中段******//
   while(1)
   {
    ;
   }
   
}


void interrupt timer1int()
{

  
    if(pwmval<1000)
    
    pwmval+=100;
     
    else  pwmval=0; 
   
   *CMPR1=pwmval; 
   *CMPR3=pwmval;
    
  *EVAIFRA=*EVAIFRA|0X0080; //******清除中断标志位******//
  asm(" clrc INTM ");
  return;
 
}
void interrupt nothing()
{
 return;
}