复件 (2) pwm.c

AVR的PWM测试程序

#include <mega128.h>  
void hsdkkmg();		//打开看门狗
void hsqnbkmg();		//清内部看门  
void main()
{ 
     PORTA = 0x00;
 DDRA  = 0x00;
 PORTB = 0x00;
 DDRB  = 0x80;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x00;
 PORTE = 0x00;
 DDRE  = 0x00;
 PORTF = 0x00;
 DDRF  = 0x00;
 PORTG = 0x00;
 DDRG  = 0x00;  
 MCUCR = 0x00;
 EICRA = 0x00; //extended ext ints
 EICRB = 0x00; //extended ext ints
 EIMSK = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 ETIMSK = 0x00; //extended timer interrupt sourcesterrupt sources
{
 TCCR2 = 0x00; //stop
 TCNT2 = 127; //setup  高电位时间
 OCR2  = 127;         //低电位时间
 TCCR2 = 0x62; //start
}
 while(1)  
	{    
	    hsdkkmg();		//打开看门狗
		hsqnbkmg();		//清内部看门
	}
}   			
//打开看门狗
void hsdkkmg()
{  
	#asm ("cli")
	WDTCR = 0x1f;
	#asm ("sei")
}			
//清内部看门狗
void hsqnbkmg()
{
	#asm("wdr")
}