/****************************************************************************/
/* UART test program														*/
/* MPU: ATmega644P															*/
/* ENV: WinAVR-20060421														*/
/*																			*/
/* 2009.04.05	new															*/
/*															(C) jujurou		*/
/****************************************************************************/

#include	<avr/io.h>
#include	<util/delay.h>


void	main(void)
{
	volatile uint8_t	uart_read_data;
	uint8_t				uart_status;

	PORTA	= 0b11111111;	/* PUPUPUPUPUPUPUPU	*/
	DDRA	= 0b00000000;	/* 入入入入入入入入	*/
	PORTB	= 0b11111111;	/* PUPUPUPUPUPUPUPU	*/
	DDRB	= 0b00000000;	/* 入入入入入入入入	*/
	PORTC	= 0b11111111;	/* PUPUPUPUPUPUPUPU	*/
	DDRC	= 0b00000000;	/* 入入入入入入入入	*/
	PORTD	= 0b11111100;	/* PUPUPUPUPUPU１０	*/
	DDRD	= 0b00000010;	/* 入入入入入入出入	*/

	UBRR0	= 25;			/* 8MHz 19200bps	*/
	UCSR0C	= 0b00000110;
	UCSR0A	= 0b01100000;
	UCSR0B	= 0b00011000;

	uart_read_data	= UDR0;

#if 0
	/* 送信テスト	*/
	UDR0	= 'A';
	while (1) {
		loop_until_bit_is_set(UCSR0A, UDRE0);
		UDR0	= 'A';
	}
#else
	/* 受送信テスト	*/
	while (1) {
		loop_until_bit_is_set(UCSR0A, RXC0);
		uart_status		= UCSR0A;
		if ((uart_status & 0b00011100) == 0) {
			uart_read_data	= UDR0;
			loop_until_bit_is_set(UCSR0A, UDRE0);
			UDR0	= uart_read_data - 1;
		} else {
			uart_read_data	= UDR0;
		}
	}
#endif


	return;
}