Hardware SPI
[Architecture and hardware specific services]

Files
file	spi.c
	SPI implementation (license: GPLv2).
file	spi.h
	SPI header (license: GPLv2).
file	spi_config.h
	SPI support configuration (license: GPLv2 or LGPLv2.1).
Functions
void	spi_init ()
	Initializes the SPI interface.
void	spi_send_byte (uint8_t b)
	Sends a byte over the SPI bus.
uint8_t	spi_rec_byte ()
	Receives a byte from the SPI bus.
void	spi_send_data (const uint8_t *data, uint16_t data_len)
	Sends data contained in a buffer over the SPI bus.
void	spi_rec_data (uint8_t *buffer, uint16_t buffer_len)
	Receives multiple bytes from the SPI bus and writes them to a buffer.
void	spi_low_frequency ()
	Switches to the lowest SPI frequency possible.
void	spi_high_frequency ()
	Switches to the highest SPI frequency possible.

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Function Documentation

void spi_init

(

)

Initializes the SPI interface.

By default, the highest SPI frequency available is used.

void spi_send_byte

(

uint8_t

b

)

Sends a byte over the SPI bus.

Parameters:

[in]

b

The byte to send.

uint8_t spi_rec_byte

(

)

Receives a byte from the SPI bus.

Returns:

The received byte.

void spi_send_data	(	const uint8_t *	data,
		uint16_t	data_len
	)

Sends data contained in a buffer over the SPI bus.

Parameters:

[in]	data	A pointer to the buffer which contains the data to send.
[in]	data_len	The number of bytes to send.

void spi_rec_data	(	uint8_t *	buffer,
		uint16_t	buffer_len
	)

Receives multiple bytes from the SPI bus and writes them to a buffer.

Parameters:

[out]	buffer	A pointer to the buffer into which the data gets written.
[in]	buffer_len	The number of bytes to read.