led._c

这是关于AVR单片机学习的初步开发

//ICC-AVR application builder : 2005-3-2 上午 11:46:11
// Target : M8
// Crystal: 11.059Mhz

#include <iom8v.h>
#include <macros.h>

void port_init(void)
{
 PORTB = 0x00;
 DDRB  = 0xFF;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x7F;
 PORTD = 0x00;
 DDRD  = 0xFF;
}

//TIMER1 initialisation - prescale:256
// WGM: 0) Normal, TOP=0xFFFF
// desired value: 1Sec
// actual value:  1.000Sec (0.0%)
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0x57; //setup
 TCNT1L = 0x41;
 OCR1AH = 0xA8;
 OCR1AL = 0xBF;
 OCR1BH = 0xA8;
 OCR1BL = 0xBF;
 ICR1H  = 0xA8;
 ICR1L  = 0xBF;
 TCCR1A = 0x00;
 TCCR1B = 0x04; //start Timer
}

#pragma interrupt_handler timer1_ovf_isr:9
void timer1_ovf_isr(void)
{
 //TIMER1 has overflowed
 TCNT1H = 0x57; //reload counter high value
 TCNT1L = 0x41; //reload counter low value
 
 
 
 PORTB = ~PORTB;
 PORTC = ~PORTC;
 PORTD = ~PORTD;
 
 TCCR1A = 0x00;
 TCCR1B = 0x04; //start Timer
}

//call this routine to initialise 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 initialised
}


void main(void)
{
while(1);

}