/*
	查詢方式UART測試程序 
	main.c
	MCU:AT90S2313
	時鐘：4MHz
	
	芯藝 2004-09-18
*/

#include <avr/io.h>

#define uchar unsigned char
#define uint unsigned int

void putc(uchar c)
{
	loop_until_bit_is_set(UCR,UDRE);
	UDR=c;
}

uchar getc(void)
{
	loop_until_bit_is_set(UCR,RXC);	
	return UDR;
}

int  main(void) 
{
	//uart 初始化
 	UCR=(1<<RXEN)|(1<<TXEN);	
	UBRR=25; //baud=9600    UBRR=CK/(9600*16) -1   
	
	while(1)
	{
		putc(getc());
	}
}