#include<iom128v.h>
#include<macros.h>
#define com0	
#define fosc 4000000 //晶振4MHZ
#define baud 2400	 //波特率
#define RXC_BUFF_SIZE 64
#define TXC_BUFF_SIZE 64
unsigned char RXC_BUFF[RXC_BUFF_SIZE];
unsigned char TXC_BUFF[TXC_BUFF_SIZE];
unsigned char RXC_RD;//接受緩沖區讀指針
unsigned char RXC_WR;//接受緩沖區寫指針
unsigned char TXC_RD;//發送緩沖區讀指針
unsigned char TXC_WR;//發送緩沖區寫指針
#ifdef com0
void uart0_init(void)
{
 UCSR0B = 0x00; //disable while setting baud rate
 UCSR0A = 0x00;
 UCSR0C =(1<<UCSZ01)|(1<<UCSZ00);//8bit+1bit stop
 UBRR0L=(fosc/16/(baud+1))%256;
 UBRR0H=(fosc/16/(baud+1))/256;
 UCSR0B =(1<<RXEN0)|(1<<TXEN0)|(1<<RXCIE0);//RXCEN TXCEN RXCIE
}
#else
void uart1_init(void)
{
 UCSR1B = 0x00; //disable while setting baud rate
 UCSR1A = 0x00;
 UCSR1C = (1<<UCSZ11)|(1<<UCSZ10);//8bit+1bit stop
 UBRR1L=(fosc/16/(baud+1))%256;
 UBRR1H=(fosc/16/(baud+1))/256;
 UCSR1B =(1<<RXEN1)|(1<<TXEN1)|(1<<RXCIE1);//RXCEN TXCEN RXCIE
}
#endif
void putchar(unsigned char c)
	{	 
     TXC_BUFF[TXC_WR]=c;
	 if(TXC_WR<(TXC_BUFF_SIZE-1))
	    TXC_WR++;
	 else  
	    TXC_WR=0;
	 #ifdef com0
	     UCSR0B|=(1<<UDRIE0);//開啟UDRE中斷
	 #else
	     UCSR1B|=(1<<UDRIE1);
	 #endif	
	}
unsigned char getchar(void)
  	{
	 unsigned temp;
     while(RXC_RD==RXC_WR)
	     ;
	 temp=RXC_BUFF[RXC_RD];
	 if(RXC_RD<(RXC_BUFF_SIZE-1))
	   RXC_RD++;
	 else
	   RXC_RD=0;  
	 return temp;    
	}			
void puts(char *s)
	{
	while (*s)
		{
		putchar(*s);
		s++;
		}	
    putchar(0x0a);
	putchar(0x0d);
	}
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 XDIV  = 0x00; //xtal divider
 XMCRA = 0x00; //external memory
 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
 //all peripherals are now initialised
}		
void main(void)
{
 unsigned char i;
 TXC_RD=0;
 TXC_WR=0;
 RXC_RD=0;
 RXC_WR=0;
 init_devices();
 #ifdef com0 
 	uart0_init(); 	
 #else
 	uart1_init(); 	
 #endif
 SEI();
 puts("HELLO!"); 
 while(1)
    {
     if (getchar()=='t')//按鍵盤t鍵開始測試
    	{
    	 puts("test ok!");
    	 for (i=0;i<10;i++)
    		 {
    		   putchar(0x30+i);
    		 }
    	 putchar(0x0a);
    	 putchar(0x0d); 		 
    	}	   	 
	}
}
//中斷例程	
#ifdef com0
    #pragma interrupt_handler uart0_rx_isr:iv_USART0_RXC
    void uart0_rx_isr(void)
    {
     RXC_BUFF[RXC_WR]=UDR0;
     if(RXC_WR<(RXC_BUFF_SIZE-1))
    	 RXC_WR++;
     else
    	 RXC_WR=0;	//uart has received a character in UDR
    }
    #pragma interrupt_handler uart0_udre_isr:iv_USART0_UDRE
    void uart0_udre_isr(void)
    {
     UDR0=TXC_BUFF[TXC_RD];//character transferred to shift register so UDR is now empty
	 if(TXC_RD<(TXC_BUFF_SIZE-1))
	    TXC_RD++;
	 else
	    TXC_RD=0;
	 if(TXC_RD==TXC_WR)
	    UCSR0B&=~(1<<UDRIE0);
    }
#else
    #pragma interrupt_handler uart1_rx_isr:iv_USART1_RXC
    void uart1_rx_isr(void)
    {
     RXC_BUFF[RXC_WR]=UDR1;
     if(RXC_WR<(RXC_BUFF_SIZE-1))
    	  RXC_WR++;
     else
    	  RXC_WR=0;	//uart has received a character in UDR
    }
    #pragma interrupt_handler uart1_udre_isr:iv_USART1_UDRE
    void uart1_udre_isr(void)
    {
     UDR1=TXC_BUFF[TXC_RD];//character transferred to shift register so UDR is now empty
	 if(TXC_RD<(TXC_BUFF_SIZE-1))
	    TXC_RD++;
	 else
	    TXC_RD=0;
	 if(TXC_RD==TXC_WR)
	    UCSR1B&=~(1<<UDRIE1);
    }
#endif