Embedded lab #3

4bitcounter.c

#include <p89v51rx2.h>

void delay(unsigned int dela)
{
	unsigned int i,j;
	 
	for(i=0;i<=1000;i++)
	  for(j=0;j<=dela;j++);
}

sbit l1  = P3^0;
sbit l2  = P3^1;
sbit l3  = P3^6;
sbit l4  = P3^7;

void main() {
	int count = 0;
	int tmp;
	l2 = l3 = l4 = 1;
	
	while(1)
	{
		delay(250);
		count = (count + 1) % 16;
		
		tmp = count;
		
		l4 = !(tmp % 2);
		tmp /= 2;
		
		l3 = !(tmp % 2);
		tmp /= 2;
		
		l2 = !(tmp % 2);
		tmp /= 2;
		
		l1 = !(tmp % 2);
		tmp /= 2;
	}
}