#include <mega16.h>
#define xtal 1000000

char digits[8]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07};
unsigned char;
unsigned char p_state;
unsigned char key;
unsigned char i;

void main(void)
{

PORTB=0x00;
DDRB=0xFF;
DDRD = 0xFF;
PORTD = digits[0];
DDRC = 0x00;
PORTC = 0xFF;

// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: 15.625 kHz
// Mode: Phase correct PWM top=FFh
// OC0 output: Non-Inverted PWM
TCCR0=0x63;
TCNT0=0x00;
OCR0=10;

while (1)
{
        if(!PINC.0)
	{
	        if(key!=p_state)
	        {
	                if(i==7)
	                {
	                        i=0;
        	                PORTC=digits[0];
        	        }
        	        else
        	                i++;
	        
	                PORTD = digits[i];
	                OCR0 = i*10+10;
        	        p_state=key;
	        };
	}
	else
	        p_state=0xFF;	

      };
}