//[소스] getch()함수 만들기 : 인터럽트방식으로 시리얼 통신에서 데이터 수신하기

//ICC-AVR application builder : 2011-01-19 오전 11:44:58
// Target : M128
// Crystal: 16.000Mhz

#include <iom128v.h>
#include <stdio.h>
#include <macros.h>

#define UART0 0
#define UART1 1
#define ON 1
#define OFF 0

volatile int which=UART0;
volatile unsigned char RXdata0, RXdata1;
volatile int RXon0=OFF, RXon1=OFF;
// printf 함수 사용시 추가할 것.
int putchar(char c)
{
  if(which==UART0){ 
        while (((UCSR0A>>UDRE0)&0x01) == 0) ;  // UDRE, data register empty
    UDR0 = c;
  }
  if(which==UART1){ 
        while (((UCSR1A>>UDRE0)&0x01) == 0) ;  // UDRE, data register empty
    UDR1 = c;
  }
  return c;
}
// scanf 함수 사용시 추가할 것.
int getchar(void)
{
  if(which==UART0){
    while ((UCSR0A & 0x80) == 0);
    return UDR0;
  }
  if(which==UART1){
    while ((UCSR1A & 0x80) == 0);
    return UDR1;
  }
}

// getch 함수 사용시 추가할 것.
int getch(void)
{
  unsigned char ch0, ch1;

  if(which==UART0){
    if(RXon0==ON){
          ch0=RXdata0;
          RXon0=OFF;
    }else ch0=0x00;
        return ch0;
  }
 
  if(which==UART1){
    if(RXon1==ON){
          ch1=RXdata1;
          RXon1=OFF;
    }else ch1=0x00;
        return ch1;
  }
}

void port_init(void)
{
 PORTA = 0x00;
 DDRA  = 0x00;
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x00;
 PORTE = 0x00;
 DDRE  = 0x00;
 PORTF = 0x00;
 DDRF  = 0x00;
 PORTG = 0x00;
 DDRG  = 0x00;
}

//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
 UCSR0B = 0x00; //disable while setting baud rate
 UCSR0A = 0x00;
 UCSR0C = 0x06;
 UBRR0L = 0x67; //set baud rate lo
 UBRR0H = 0x00; //set baud rate hi
 UCSR0B = 0x98;
}

#pragma interrupt_handler uart0_rx_isr:iv_USART0_RXC
void uart0_rx_isr(void)
{
 //uart has received a character in UDR
  RXdata0=UDR0;
  RXon0=ON;
}

//UART1 initialize
// desired baud rate:9600
// actual baud rate:9615 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart1_init(void)
{
 UCSR1B = 0x00; //disable while setting baud rate
 UCSR1A = 0x00;
 UCSR1C = 0x06;
 UBRR1L = 0x67; //set baud rate lo
 UBRR1H = 0x00; //set baud rate hi
 UCSR1B = 0x98;
}

#pragma interrupt_handler uart1_rx_isr:iv_USART1_RXC
void uart1_rx_isr(void)
{
 //uart has received a character in UDR
  RXdata1=UDR1;
  RXon1=ON;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 XDIV  = 0x00; //xtal divider
 XMCRA = 0x00; //external memory
 port_init();
 uart0_init();
 uart1_init();

 MCUCR = 0x00;
 EICRA = 0x00; //extended ext ints
 EICRB = 0x00; //extended ext ints
 EIMSK = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 ETIMSK = 0x00; //extended timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

//
void main(void)
{
  init_devices();
  //insert your functional code here...
  while(1){
    if(getch()=='a'){
          printf("a pressed");
        }
        if(getch()=='b'){
          printf("b pressed");
        }   
  }
}