Serial Peripheral Interface (SPI)

See Quickstart guide for SAM SPI driver.

The SPI circuit is a synchronous serial data link that provides communication with external devices in Master or Slave mode. Connection to Peripheral DMA Controller channel capabilities optimizes data transfers.

Modules
	Related Project(s)
	In this section you can find all the projects related to the Serial Peripheral Interface (SPI).
	Quick Start Guide(s)
	In this section you can find a list of all Quick Start guides related to the Serial Peripheral Interface (SPI).

Macros
#define	SPI_WPMR_WPKEY_PASSWD   SPI_WPMR_WPKEY((uint32_t) 0x535049)

Functions
int16_t	spi_calc_baudrate_div (const uint32_t baudrate, uint32_t mck)
	Calculate the baudrate divider. More...
void	spi_configure_cs_behavior (Spi *p_spi, uint32_t ul_pcs_ch, uint32_t ul_cs_behavior)
	Configure CS behavior for SPI transfer (spi_cs_behavior_t). More...
void	spi_disable_clock (Spi *p_spi)
	Disable SPI clock. More...
void	spi_enable_clock (Spi *p_spi)
	Enable SPI clock. More...
uint32_t	spi_get_writeprotect_status (Spi *p_spi)
	Indicate write protect status. More...
spi_status_t	spi_read (Spi *p_spi, uint16_t *us_data, uint8_t *p_pcs)
	Read the received data and it's peripheral chip select value. More...
int16_t	spi_set_baudrate_div (Spi *p_spi, uint32_t ul_pcs_ch, uint8_t uc_baudrate_divider)
	Set Serial Clock Baud Rate divider value (SCBR). More...
void	spi_set_bits_per_transfer (Spi *p_spi, uint32_t ul_pcs_ch, uint32_t ul_bits)
	Set number of bits per transfer. More...
void	spi_set_clock_phase (Spi *p_spi, uint32_t ul_pcs_ch, uint32_t ul_phase)
	Set Data Capture Phase. More...
void	spi_set_clock_polarity (Spi *p_spi, uint32_t ul_pcs_ch, uint32_t ul_polarity)
	Set clock default state. More...
void	spi_set_delay_between_chip_select (Spi *p_spi, uint32_t ul_delay)
	Set delay between chip selects (in number of MCK clocks). More...
void	spi_set_peripheral_chip_select_value (Spi *p_spi, uint32_t ul_value)
	Set Peripheral Chip Select (PCS) value. More...
void	spi_set_transfer_delay (Spi *p_spi, uint32_t ul_pcs_ch, uint8_t uc_dlybs, uint8_t uc_dlybct)
	Configure timing for SPI transfer. More...
void	spi_set_writeprotect (Spi *p_spi, uint32_t ul_enable)
	Enable or disable write protection of SPI registers. More...
spi_status_t	spi_write (Spi *p_spi, uint16_t us_data, uint8_t uc_pcs, uint8_t uc_last)
	Write the transmitted data with specified peripheral chip select value. More...

#define SPI_WPMR_WPKEY_PASSWD   SPI_WPMR_WPKEY((uint32_t) 0x535049)

Referenced by spi_set_writeprotect().

int16_t spi_calc_baudrate_div	(	const uint32_t	baudrate,
		uint32_t	mck
	)

Calculate the baudrate divider.

Parameters

baudrate	Baudrate value.
mck	SPI module input clock frequency (MCK clock, Hz).

Returns

Divider or error code.

Return values

>	0 Success.
<	0 Error.

References div_ceil.

Referenced by spi_master_setup_device().

void spi_configure_cs_behavior	(	Spi *	p_spi,
		uint32_t	ul_pcs_ch,
		uint32_t	ul_cs_behavior
	)

Configure CS behavior for SPI transfer (spi_cs_behavior_t).

Parameters

p_spi	Pointer to an SPI instance.
ul_pcs_ch	Peripheral Chip Select channel (0~3).
ul_cs_behavior	Behavior of the Chip Select after transfer.

References SPI_CS_KEEP_LOW, SPI_CS_RISE_FORCED, and SPI_CS_RISE_NO_TX.

Referenced by ili9488_init(), and spi_master_setup_device().

void spi_disable_clock

(

Spi *

p_spi

)

Disable SPI clock.

Parameters

p_spi

Pointer to an SPI instance.

References sysclk_disable_peripheral_clock(), and UNUSED.

void spi_enable_clock

(

Spi *

p_spi

)

Enable SPI clock.

Parameters

p_spi

Pointer to an SPI instance.

References sysclk_enable_peripheral_clock(), and UNUSED.

Referenced by nm_bus_init(), spi_master_init(), spi_master_initialize(), and spi_slave_initialize().

uint32_t spi_get_writeprotect_status

(

Spi *

p_spi

)

Indicate write protect status.

Parameters

p_spi

Pointer to an SPI instance.

Returns

SPI_WPSR value.

spi_status_t spi_read	(	Spi *	p_spi,
		uint16_t *	us_data,
		uint8_t *	p_pcs
	)

Read the received data and it's peripheral chip select value.

While SPI works in fixed peripheral select mode, the peripheral chip select value is meaningless.

Parameters

p_spi	Pointer to an SPI instance.
data	Pointer to the location where to store the received data word.
p_pcs	Pointer to fill Peripheral Chip Select Value.

Return values

SPI_OK	on Success.
SPI_ERROR_TIMEOUT	on Time-out.

References SPI_ERROR_TIMEOUT, spi_get_peripheral_select_mode(), SPI_OK, and SPI_TIMEOUT.

int16_t spi_set_baudrate_div	(	Spi *	p_spi,
		uint32_t	ul_pcs_ch,
		uint8_t	uc_baudrate_divider
	)

Set Serial Clock Baud Rate divider value (SCBR).

Parameters

p_spi	Pointer to an SPI instance.
ul_pcs_ch	Peripheral Chip Select channel (0~3).
uc_baudrate_divider	Baudrate divider from MCK.

Returns

Return values

is	0 Success.
is	-1 Error.

Referenced by nm_bus_init(), spi_master_initialize(), and spi_master_setup_device().

void spi_set_bits_per_transfer	(	Spi *	p_spi,
		uint32_t	ul_pcs_ch,
		uint32_t	ul_bits
	)

Set number of bits per transfer.

Parameters

p_spi	Pointer to an SPI instance.
ul_pcs_ch	Peripheral Chip Select channel (0~3).
ul_bits	Number of bits (8~16), use the pattern defined in the device header file.

Referenced by nm_bus_init(), spi_master_initialize(), spi_master_setup_device(), and spi_slave_initialize().

void spi_set_clock_phase	(	Spi *	p_spi,
		uint32_t	ul_pcs_ch,
		uint32_t	ul_phase
	)

Set Data Capture Phase.

Parameters

p_spi	Pointer to an SPI instance.
ul_pcs_ch	Peripheral Chip Select channel (0~3).
ul_phase	Data capture on the rising/falling edge of clock.

Referenced by nm_bus_init(), spi_master_initialize(), spi_master_setup_device(), and spi_slave_initialize().

void spi_set_clock_polarity	(	Spi *	p_spi,
		uint32_t	ul_pcs_ch,
		uint32_t	ul_polarity
	)

Set clock default state.

Parameters

p_spi	Pointer to an SPI instance.
ul_pcs_ch	Peripheral Chip Select channel (0~3).
ul_polarity	Default clock state is logical one(high)/zero(low).

Referenced by nm_bus_init(), spi_master_initialize(), spi_master_setup_device(), and spi_slave_initialize().

void spi_set_delay_between_chip_select	(	Spi *	p_spi,
		uint32_t	ul_delay
	)

Set delay between chip selects (in number of MCK clocks).

If DLYBCS <= 6, 6 MCK clocks will be inserted by default.

Parameters

p_spi	Pointer to an SPI instance.
ul_delay	Delay between chip selects (in number of MCK clocks).

Referenced by spi_master_init().

void spi_set_peripheral_chip_select_value	(	Spi *	p_spi,
		uint32_t	ul_value
	)

Set Peripheral Chip Select (PCS) value.

Parameters

p_spi	Pointer to an SPI instance.
ul_value	Peripheral Chip Select value. If PCS decode mode is not used, use spi_get_pcs to build the value to use. On reset the decode mode is not enabled. The decode mode can be enabled/disabled by follow functions: spi_enable_peripheral_select_decode, spi_disable_peripheral_select_decode.

Referenced by nm_bus_init(), spi_deselect_device(), spi_master_init(), spi_master_initialize(), spi_select_device(), and spi_slave_initialize().

void spi_set_transfer_delay	(	Spi *	p_spi,
		uint32_t	ul_pcs_ch,
		uint8_t	uc_dlybs,
		uint8_t	uc_dlybct
	)

Configure timing for SPI transfer.

Parameters

p_spi	Pointer to an SPI instance.
ul_pcs_ch	Peripheral Chip Select channel (0~3).
uc_dlybs	Delay before SPCK (in number of MCK clocks).
uc_dlybct	Delay between consecutive transfers (in number of MCK clocks).

Referenced by nm_bus_init(), spi_master_initialize(), and spi_master_setup_device().

void spi_set_writeprotect	(	Spi *	p_spi,
		uint32_t	ul_enable
	)

Enable or disable write protection of SPI registers.

Parameters

p_spi	Pointer to an SPI instance.
ul_enable	1 to enable, 0 to disable.

References SPI_WPMR_WPKEY_PASSWD.

spi_status_t spi_write	(	Spi *	p_spi,
		uint16_t	us_data,
		uint8_t	uc_pcs,
		uint8_t	uc_last
	)

Write the transmitted data with specified peripheral chip select value.

Parameters

p_spi	Pointer to an SPI instance.
us_data	The data to transmit.
uc_pcs	Peripheral Chip Select Value while SPI works in peripheral select mode, otherwise it's meaningless.
uc_last	Indicate whether this data is the last one while SPI is working in variable peripheral select mode.

Return values

SPI_OK	on Success.
SPI_ERROR_TIMEOUT	on Time-out.

References SPI_ERROR_TIMEOUT, spi_get_peripheral_select_mode(), SPI_OK, and SPI_TIMEOUT.

Referenced by ili9488_write_ram(), ili9488_write_ram_prepare(), and ili9488_write_register().