이거 해석좀!!

// Target : M128
// Crystal: 16.000Mhz
#include <stdio.h>
#include <iom128v.h>
#include <macros.h>

char state;
char data;
char count;
char len_L,len_H;
char r_data[23];
char complete;

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: 19200
// actual: baud rate:19231 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
 UCSR0B = 0x00; //disable while setting baud rate
 UCSR0A = 0x00;
 UCSR0C = 0x06;
 UBRR0L = 0x33; //set baud rate lo
 UBRR0H = 0x00; //set baud rate hi
 UCSR0B = 0x18;
}

//UART1 initialize
// desired baud rate:57600
// actual baud rate:58824 (2.1%)
// char size: 8 bit
// parity: Disabled
void uart1_init(void)
{
 UCSR1B = 0x00; //disable while setting baud rate
 UCSR1A = 0x00;
 UCSR1C = 0x06;
 UBRR1L = 0x10; //set baud rate lo
 UBRR1H = 0x00; //set baud rate hi
 UCSR1B = 0x98;
}

#pragma interrupt_handler uart1_rx_isr:31
void uart1_rx_isr(void)
{
 //uart has received a character in UDR
 data=UDR1;
 
 if(state==4)
 {
  if(data==0x03)
 {
  state=0;
  count=0;
  complete=1;
 }
  
 }else if(state==3)
 {
  r_data[count]=data;
 count++;
 if(count==len_L)state=4;
   
 }else if(state==2)
 {
 len_H=data;
 state=3;
 }else if(state==1)
 {
 len_L=data;
 state=2;
 }else if(data==0x02)state=1;
 
}

//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 delay_ms(unsigned int ms)
{
 unsigned int i;
 while(ms--)
 {
  i=2727;
  while(i--);
 }
}

void USART_Transmit( unsigned char data )
{
 /* Wait for empty transmit buffer */
 while ( !( UCSR1A & (1<<UDRE1)) );
 /* Put data into buffer, sends the data */
 UDR1 = data;
}

void check_ID(void)
{
 char i;
 char send[]={0x02,0x01,0x00,0x70,0x73,0x03};
 printf("Check ID.\\r\\n");

 for(i=0;i<6;i++)USART_Transmit(send[i]);
}

void Read_data(char addr)
{
 char i;
 char lrc=0x00;
 char send[]={0x02,0x02,0x00,0x71,0x00,0x00,0x03};
 send[4]=addr;
 printf("Read data.\\r\\n");

 for(i=0;i<7;i++)
 {
  if(i==5)send[5]=lrc;

  USART_Transmit(send[i]);
  lrc^=send[i];
 }
 
}
void Write_data(char addr, char *str)
{
 char i;
 char lrc=0x00;
 char send[]={0x02,0x12,0x00,0x72,0x00};
 send[4]=addr;

 printf("Write data.\\r\\n");

 for(i=0;i<5;i++)
 {
  USART_Transmit(send[i]);
  lrc^=send[i];
 }
 for(i=0;i<16;i++)
 {
  if(*str==NULL)USART_Transmit(0x00);
  else
  {
   USART_Transmit(*str);
   lrc^=*str;
   str++;

  }
 }
 USART_Transmit(lrc);
 USART_Transmit(0x03);
 
}

void init_var(void)
{
 data=0;
 len_L=len_H=0;
 state=0;
 complete=0;
 
}
void main(void)
{
 char i;
 char *str="Korea";
 init_var();
 init_devices();
 
 delay_ms(500);
 //check_ID();
 //Write_data(0x01, str);
 Write_data(0x01, "우리나라");
 delay_ms(3000);
 Read_data(0x01);

 while(1)
 {
  if(complete==1)
  {
   for(i=0;i<len_L;i++)
   {
    if(r_data[i]!=NULL)printf("%c",r_data[i]);
   }
   printf("\\r\\n");
   complete=0;
  }
 }
}