cllock.c

AVR Devolpment Board

#include "avr/io.h"
#include "util/delay.h"
#include "avr/pgmspace.h"
#include "avr/interrupt.h"

const prog_char SegCode[]={
0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,/* 0,1,2,3,4,5,6,7,8,9 */
0x77,0x7c,0x39,0x5e,0x79,0x71,0x00,0x40           /* a,b,c,d,e,f, ,-     */
};

#define SPACE  16
#define LINE   17 

volatile unsigned char DisBuffer[8];
volatile unsigned long ClockCnt=0;


void TimerConfig(void)
{
	TCCR0=(1<<CS01)|(1<<CS00);     //控制寄存器，工作方式及时钟选择
	TCNT0=(256-250);//计数值	
	TIMSK=0x01;     //中断控制
	sei();
}

SIGNAL(TIMER0_OVF_vect)
{
	static unsigned char i=0;
	static unsigned int  Cnt=0;
	TCNT0=(256-250);
	
	PORTB = pgm_read_byte(&SegCode[DisBuffer[i]]);
	PORTA|= (1<<PA4);
	PORTA&=~(1<<PA4);	
				
	PORTB = (1<<i);
	PORTA|= (1<<PA5);
	PORTA&=~(1<<PA5);

	i++;
	if(i==8)
		i=0;

	Cnt++;
	if(Cnt==500)
	{
		Cnt=0;
		ClockCnt++;
		if(ClockCnt>=86400)
			ClockCnt=0;
	}
}

int main(void)
{
	/* Set LED and Smg LE pin as output , databus as output */
	DDRA |=(1<<PA4)|(1<<PA5)|(1<<PA6); 
	DDRB  = 0xFF;

	/* Off the LED display */
	
	PORTB = 0xFF;
	PORTA|= (1<<PA6);
	PORTA&=~(1<<PA6);

	TimerConfig();
	while(1)
	{
		DisBuffer[0]=ClockCnt/3600/10;
		DisBuffer[1]=ClockCnt/3600%10;
		DisBuffer[2]=LINE;
		DisBuffer[3]=ClockCnt/60/10%6;
		DisBuffer[4]=ClockCnt/60%10;
		DisBuffer[5]=LINE;
		DisBuffer[6]=ClockCnt/10%6;
		DisBuffer[7]=ClockCnt%10;
	}
	return 0;
}