SAM USART in SPI mode driver functions.

#include "usart_spi.h"
#include "sysclk.h"

Functions
void	usart_spi_deselect_device (Usart p_usart, struct usart_spi_device device)
	De-select the given device on the SPI bus. More...

void	usart_spi_disable (Usart *p_usart)
	Disable the USART for the specified USART in SPI mode. More...

void	usart_spi_enable (Usart *p_usart)
	Enable the USART for the specified USART in SPI mode. More...

void	usart_spi_init (Usart *p_usart)
	Enable the USART system clock in SPI master mode. More...

uint32_t	usart_spi_is_rx_full (Usart *p_usart)
	Check if both receive buffers are full. More...

uint32_t	usart_spi_is_rx_ready (Usart *p_usart)
	Check whether the USART in SPI master mode contains a received character. More...

uint32_t	usart_spi_is_tx_empty (Usart *p_usart)
	Check whether there are data in Transmit Holding Register or Transmit Shift Register in SPI master mode. More...

uint32_t	usart_spi_is_tx_ready (Usart *p_usart)
	Check if the USART Transmit Holding Register is empty or not in SPI mode. More...

uint32_t	usart_spi_read_packet (Usart p_usart, uint8_t data, size_t len)
	Receive a sequence of bytes from a USART in SPI mode device. More...

void	usart_spi_read_single (Usart p_usart, uint8_t data)
	Receive one byte from an SPI device using USART in SPI mode. More...

void	usart_spi_select_device (Usart p_usart, struct usart_spi_device device)
	Select the given device on the SPI bus. More...

void	usart_spi_setup_device (Usart p_usart, struct usart_spi_device device, spi_flags_t flags, unsigned long baud_rate, board_spi_select_id_t sel_id)
	Set up a USART in SPI master mode device. More...

uint32_t	usart_spi_write_packet (Usart p_usart, const uint8_t data, size_t len)
	Send a sequence of bytes to an SPI device using USART in SPI mode. More...

void	usart_spi_write_single (Usart *p_usart, uint8_t data)
	Write one byte to an SPI device using USART in SPI mode. More...

void usart_spi_deselect_device	(	Usart *	p_usart,
		struct usart_spi_device *	device
	)

De-select the given device on the SPI bus.

Parameters

p_usart	Base address of the USART instance.
device	SPI device.

References UNUSED, and usart_spi_release_chip_select().

Referenced by at25dfx_spi_deselect_device(), ssd1306_write_command(), and ssd1306_write_data().

void usart_spi_disable ( Usart * p_usart )

Disable the USART for the specified USART in SPI mode.

Ensure that nothing is transferred while setting up buffers.

Parameters

p_usart Base address of the USART instance.

References usart_disable_rx(), and usart_disable_tx().

void usart_spi_enable ( Usart * p_usart )

Enable the USART for the specified USART in SPI mode.

Parameters

p_usart Base address of the USART instance.

References usart_enable_rx(), and usart_enable_tx().

void usart_spi_init ( Usart * p_usart )

Enable the USART system clock in SPI master mode.

Parameters

p_usart Pointer to Base address of the USART instance.

References sysclk_enable_peripheral_clock().

Referenced by at25dfx_spi_init(), at45dbx_spi_init(), and ssd1306_interface_init().

uint32_t usart_spi_is_rx_full ( Usart * p_usart )

Check if both receive buffers are full.

Parameters

p_usart Base address of the USART instance.

Return values

1	Receive buffers are full.
0	Receive buffers are not full.

References usart_is_rx_buf_full().

uint32_t usart_spi_is_rx_ready ( Usart * p_usart )

Check whether the USART in SPI master mode contains a received character.

Parameters

p_usart Base address of the USART instance.

Return values

1	Some data have been received.
0	No data has been received.

References usart_is_rx_ready().

uint32_t usart_spi_is_tx_empty ( Usart * p_usart )

Check whether there are data in Transmit Holding Register or Transmit Shift Register in SPI master mode.

Parameters

p_usart Base address of the USART instance.

Return values

1	The two registers are empty.
0	One of the two registers contains data.

References usart_is_tx_empty().

uint32_t usart_spi_is_tx_ready ( Usart * p_usart )

Check if the USART Transmit Holding Register is empty or not in SPI mode.

Parameters

p_usart Base address of the USART instance.

Return values

1	There is no data in the Transmit Holding Register.
0	There are data in the Transmit Holding Register.

References usart_is_tx_ready().

uint32_t usart_spi_read_packet	(	Usart *	p_usart,
		uint8_t *	data,
		size_t	len
	)

Receive a sequence of bytes from a USART in SPI mode device.

All bytes sent out on usart bus are sent as value 0.

Parameters

p_usart	Base address of the usart instance.
data	Data buffer to put read data.
len	Length of data.

Returns: 0 if the USART in SPI master mode reads packet successfully.

Precondition: USART device must be selected with usart_spi_select_device() first.

References CONFIG_USART_SPI_DUMMY, usart_getchar(), and usart_putchar().

Referenced by at25dfx_spi_read_byte(), and at25dfx_spi_read_packet().

void usart_spi_read_single	(	Usart *	p_usart,
		uint8_t *	data
	)

Receive one byte from an SPI device using USART in SPI mode.

Parameters

p_usart	Base address of the USART instance.
data	Pointer to the data byte where to store the received data.

Precondition: USART device must be selected with usart_spi_select_device() first.

References CONFIG_USART_SPI_DUMMY, usart_getchar(), and usart_putchar().

void usart_spi_select_device	(	Usart *	p_usart,
		struct usart_spi_device *	device
	)

Select the given device on the SPI bus.

Parameters

p_usart	Base address of the USART instance.
device	SPI device.

References UNUSED, and usart_spi_force_chip_select().

Referenced by at25dfx_spi_select_device(), ssd1306_write_command(), and ssd1306_write_data().

void usart_spi_setup_device	(	Usart *	p_usart,
		struct usart_spi_device *	device,
		spi_flags_t	flags,
		unsigned long	baud_rate,
		board_spi_select_id_t	sel_id
	)

Set up a USART in SPI master mode device.

The returned device descriptor structure must be passed to the driver whenever that device should be used as current slave device.

Parameters

p_usart	Base address of the USART instance.
device	Pointer to usart device struct that should be initialized.
flags	USART configuration flags. Common flags for all implementations are the usart modes, which should be SPI_MODE_0, SPI_MODE_1, SPI_MODE_2, SPI_MODE_3.
baud_rate	Baud rate for communication with slave device in Hz.
sel_id	Board specific select id.

References usart_spi_opt_t::baudrate, usart_spi_opt_t::channel_mode, usart_spi_opt_t::char_length, usart_spi_opt_t::spi_mode, sysclk_get_pba_hz(), UNUSED, usart_enable_rx(), usart_enable_tx(), and usart_init_spi_master().

Referenced by at25dfx_spi_init(), and ssd1306_interface_init().

uint32_t usart_spi_write_packet	(	Usart *	p_usart,
		const uint8_t *	data,
		size_t	len
	)

Send a sequence of bytes to an SPI device using USART in SPI mode.

Received bytes on the USART in SPI mode are discarded.

Parameters

p_usart	Base address of the USART instance.
data	Data buffer to write.
len	Length of data.

Returns: 0 if the USART in SPI master mode sends packet successfully.

Precondition: USART device must be selected with usart_spi_select_device() first.

References usart_getchar(), and usart_putchar().

Referenced by at25dfx_spi_write_byte(), and at25dfx_spi_write_packet().

void usart_spi_write_single	(	Usart *	p_usart,
		uint8_t	data
	)

Write one byte to an SPI device using USART in SPI mode.

Parameters

p_usart	Base address of the USART instance.
data	The data to be sent out.

References usart_putchar().

Microchip® Advanced Software Framework

Functions