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507 kaklik 1 
/*------------------------------------------------*/
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/* UART functions                                 */
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include "uart.h"
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#define	SYSCLK		9216000
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#define	BAUD		115200
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typedef struct _fifo {
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	uint8_t	idx_w;
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	uint8_t	idx_r;
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	uint8_t	count;
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	uint8_t buff[64];
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} FIFO;
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static volatile
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FIFO txfifo, rxfifo;
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/* Initialize UART */
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void uart_init()
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{
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	rxfifo.idx_r = 0;
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	rxfifo.idx_w = 0;
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	rxfifo.count = 0;
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	txfifo.idx_r = 0;
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	txfifo.idx_w = 0;
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	txfifo.count = 0;
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	UBRR0L = SYSCLK/BAUD/16-1;
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	UCSR0B = _BV(RXEN0)|_BV(RXCIE0)|_BV(TXEN0);
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}
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/* Get a received character */
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uint8_t uart_test ()
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{
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	return rxfifo.count;
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}
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uint8_t uart_get ()
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{
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	uint8_t d, i;
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	i = rxfifo.idx_r;
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	while(rxfifo.count == 0);
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	d = rxfifo.buff[i++];
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	cli();
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	rxfifo.count--;
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	sei();
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	if(i >= sizeof(rxfifo.buff))
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		i = 0;
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	rxfifo.idx_r = i;
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	return d;
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}
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/* Put a character to transmit */
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void uart_put (uint8_t d)
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{
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	uint8_t i;
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	i = txfifo.idx_w;
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	while(txfifo.count >= sizeof(txfifo.buff));
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	txfifo.buff[i++] = d;
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	cli();
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	txfifo.count++;
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	UCSR0B = _BV(RXEN0)|_BV(RXCIE0)|_BV(TXEN0)|_BV(UDRIE0);
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	sei();
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	if(i >= sizeof(txfifo.buff))
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		i = 0;
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	txfifo.idx_w = i;
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}
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/* UART RXC interrupt */
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SIGNAL(SIG_UART0_RECV)
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{
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	uint8_t d, n, i;
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	d = UDR0;
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	n = rxfifo.count;
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	if(n < sizeof(rxfifo.buff)) {
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		rxfifo.count = ++n;
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		i = rxfifo.idx_w;
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		rxfifo.buff[i++] = d;
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		if(i >= sizeof(rxfifo.buff))
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			i = 0;
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		rxfifo.idx_w = i;
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	}
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}
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/* UART UDRE interrupt */
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SIGNAL(SIG_UART0_DATA)
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{
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	uint8_t n, i;
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	n = txfifo.count;
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	if(n) {
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		txfifo.count = --n;
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		i = txfifo.idx_r;
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		UDR0 = txfifo.buff[i++];
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		if(i >= sizeof(txfifo.buff))
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			i = 0;
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		txfifo.idx_r = i;
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	}
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	if(n == 0)
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		UCSR0B = _BV(RXEN0)|_BV(RXCIE0)|_BV(TXEN0);
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}
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