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ben-wpan/atusb/fw/spi.c
2011-02-22 00:24:07 -03:00

59 lines
1.0 KiB
C

/*
* fw/spi.c - ATmega8 family SPI I/O
*
* Written 2011 by Werner Almesberger
* Copyright 2011 Werner Almesberger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <stdint.h>
#include <avr/io.h>
#include "board.h"
#include "spi.h"
void spi_begin(void)
{
CLR(nSS);
}
uint8_t spi_io(uint8_t v)
{
// while (!(UCSR1A & 1 << UDRE1));
UDR1 = v;
while (!(UCSR1A & 1 << RXC1));
return UDR1;
}
void spi_end(void)
{
// while (!(UCSR1A & 1 << TXC1));
SET(nSS);
}
void spi_init(void)
{
SET(nSS);
OUT(SCLK);
OUT(MOSI);
OUT(nSS);
IN(MISO);
UBRR1 = 0; /* set bit rate to zero to begin */
UCSR1C = 1 << UMSEL11 | 1 << UMSEL10;
/* set MSPI, MSB first, SPI data mode 0 */
UCSR1B = 1 << RXEN1 | 1 << TXEN1;
/* enable receiver and transmitter */
UBRR1 = 0; /* reconfirm the bit rate */
}