体么人

51单片机时钟程序

//ICC-AVR application builder : 2007-8-1 21:29:13
// Target : M16
// Crystal: 4.0000Mhz

#include <iom16v.h>
#include <macros.h>

const led_tab[9]={    
        0x3F,/*0*/
        0x06,/*1*/
        0x5B,/*2*/
        0x4F,/*3*/
        0x66,/*4*/
        0x6D,/*5*/
        0x7D,/*6*/
        0x07,/*7*/
        0x7F,/*8*/
        0x6F,/*9*/
		};
unsigned char timer1_ovf_count;		

void port_init(void)
{
 PORTA = 0x00;
 DDRA  = 0xFF;
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x00;
}

//TIMER1 initialize - prescale:64
// WGM: 0) Normal, TOP=0xFFFF
// desired value: 1Hz
// actual value:  1.000Hz (0.0%)
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0x0B; //setup
 TCNT1L = 0xDC;

 TCCR1A = 0x00;
 TCCR1B = 0x03; //start Timer
}

#pragma interrupt_handler timer1_ovf_isr:iv_TIM1_OVF
void timer1_ovf_isr(void)
{
 //TIMER1 has overflowed
 TCNT1H = 0x0B; //reload counter high value
 TCNT1L = 0xDC; //reload counter low value
 timer1_ovf_count++;
 if(timer1_ovf_count==10)
 {
 timer1_ovf_count=0;
 }
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 timer1_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x04; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

void main(void)
{
  timer1_ovf_count=0;
  while(1)
  {
  PORTA=led_tab[timer1_ovf_count];
  }
}