3._c

这是关于AVR单片机学习的初步开发

//ICC-AVR application builder : 2005-3-29 下午 11:37:28
// Target : M8
// Crystal: 11.059Mhz

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

void port_init(void)
{
 PORTB = 0xFF;
 DDRB  = 0x02;
 PORTC = 0x7F; //m103 output only
 DDRC  = 0x00;
 PORTD = 0xFF;
 DDRD  = 0x00;
}

//TIMER1 initialisation - prescale:8
// WGM: 14) PWM fast, TOP=ICRn
// desired value: 50Hz
// actual value: 50.001Hz (0.0%)
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0x94; //setup
 TCNT1L = 0x02;
 OCR1AH = 0x6B;
 OCR1AL = 0xFE;
 OCR1BH = 0x6B;
 OCR1BL = 0xFE;
 ICR1H  = 0x6B;
 ICR1L  = 0xFE;
 TCCR1A = 0xA2;
 TCCR1B = 0x1A; //start Timer
}

//UART0 initialisation
// desired baud rate: 9600
// actual: baud rate:9600 (0.0%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
 UCSRB = 0x00; //disable while setting baud rate
 UCSRA = 0x00;
 UCSRC = 0x86;
 UBRRL = 0x47; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0xD8;
}

#pragma interrupt_handler uart0_rx_isr:12
void uart0_rx_isr(void)
{
 //uart has received a character in UDR
  char temp,data;
 unsigned int time;
 
 temp = UDR;
 data = temp;
 time = (data *31>>1)+691;
 OCR1AH = time >>8;
 OCR1AL = time;
 UDR =  0x00;
}

#pragma interrupt_handler uart0_tx_isr:14
void uart0_tx_isr(void)
{
 //character has been transmitted
 ;
 
}

//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();
 uart0_init();

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

//
void main(void)
{
 init_devices();
 //insert your functional code here...
}