pwm.c

用ICC编写的程序包括SPI

#include "pwm.h"


unsigned char pwm_value[2]={0x7f,0x7f};
unsigned char pwm_flag;
//TIMER1 initialize - prescale:1
// WGM: 8) PWM phz freq correct, TOP=ICRn
// desired value: 14.4KHz
// actual value: 14.456KHz (0.4%)
void pwm_init(void)
{
 DDRD|=BIT(OC1B)|BIT(OC1A);
 //PORTD|=BIT(OC1B)|BIT(OC1A);
 TCCR1B = 0x00; //stop
 TCNT1H = 0x00; //setup
 TCNT1L = 0x00;
 OCR1AH = 0x00;
 OCR1AL = 0x7F;
 OCR1BH = 0x00;
 OCR1BL = 0x7F;
 ICR1H  = 0x00;
 ICR1L  = 0xFF;
 TCCR1A = 0xA0;
 TCCR1B = 0x11; //start Timer
 pwm_flag=0;
}

void pwm_change(void)
{ 
   if(pwm_value[0]<3)
      pwm_value[0]=3;
   if(pwm_value[0]>253)
      pwm_value[0]=253;
   OCR1AH=0x00;
   OCR1AL=pwm_value[0];
   
   if(pwm_value[1]<3)
      pwm_value[1]=3;
   if(pwm_value[1]>253)
      pwm_value[1]=253;
   OCR1BH=0x00;
   OCR1BL=pwm_value[1];
}