3.txt

使用AT89S52单片机的简易电子琴程序的KEIL工程

#include "AT89X51.H" 
#define  bell P1_7
unsigned int tab1[]={63766,63969,64135,64207,64356,64485,64595};
unsigned int j;
void main(void) 
{ 
	TMOD=0x01; 
	EA=1; 
	ET0=1;
	EX0=0;
	EX1=0; 
    while(1) 
	{ 
	    while(P3_2==0)
		{ 
			
			TH0=tab1[0]/256; 
			TL0=tab1[0]%256; 
			j=0;
			TR0=1;
		}
		while(P3_3==0)
		{ 
	
			TH0=tab1[1]/256; 
			TL0=tab1[1]%256; 
		    j=1;
			TR0=1;
		}
 
	} 
}
void timer0_int(void) interrupt 1  
{ 		
	bell=!bell;
	TH0=tab1[j]/256; 
	TL0=tab1[j]%256;
}