T/C0作为外部事件计数器使用

/*****************************************************
This program was produced by the
CodeWizardAVR V2.05.5a Evaluation


Date    : 2011/12/15


Chip type               : ATmega16
Program type            : Application
AVR Core Clock frequency: 4.000000 MHz
Memory model            : Small
External RAM size       : 0
Data Stack size         : 256
*****************************************************/

#include <mega16.h>

// Timer 0 overflow interrupt service routine
interrupt [TIM0_OVF] void timer0_ovf_isr(void)
{
// Reinitialize Timer 0 value
TCNT0=0x83;
PORTA.0 =  ~PORTA.0;

}

// Declare your global variables here

void main(void)
{

 PORTA = 0x01;
 DDRA = 0x01;
 
 PORTB =0x01;
 DDRB = 0x00;

// Timer/Counter 0 initialization
// Clock source: T0 pin Rising Edge
// Mode: Normal top=0xFF
// OC0 output: Disconnected
TCCR0=0x07;
TCNT0=0x83;
OCR0=0x00;

TIMSK = 0x01;

// Global enable interrupts
#asm("sei")

while (1)
      {
      // Place your code here

      }                                           
}