pwm.c

基于C51单片机的平滑三角波PWM发生程序,及protues仿真

#include<pic.h>
static bit flag;
void main(void)
{
TRISC=0X7B;
PR2=0XFF;
TMR2IE=1;
PEIE=1;
GIE=1;
CCP1CON=0X0C;
CCPR1L=0;
T2CON=0;
TMR2ON=1;
while(1);
}
void interrupt isr(void)
{
 PORTC^=0X80;
 TMR2IF=0;
 if(!flag)
  {
   CCPR1L++;
   if(CCPR1L==0xff)
     {
     flag=1;
     }
    }
 else
   {
    CCPR1L--;
    if(CCPR1L==0)
     {
     flag=0;
      }
    }
   }