SPI master driver

Multi-instance SPI master driver. More...

Modules
	SPI/SPIM peripheral driver configuration

Data Structures
struct	nrf_drv_spi_t
	SPI master driver instance data structure. More...
struct	nrf_drv_spi_config_t
	SPI master driver instance configuration structure. More...
struct	nrf_drv_spi_xfer_desc_t
	Single transfer descriptor structure. More...
struct	nrf_drv_spi_evt_t

Macros
#define	SPI0_INSTANCE_INDEX   0
#define	SPI1_INSTANCE_INDEX   SPI0_INSTANCE_INDEX+SPI0_ENABLED
#define	SPI2_INSTANCE_INDEX   SPI1_INSTANCE_INDEX+SPI1_ENABLED
#define	NRF_DRV_SPI_INSTANCE(id)
	Macro for creating an SPI master driver instance. More...
#define	NRF_DRV_SPI_PIN_NOT_USED   0xFF
	This value can be provided instead of a pin number for signals MOSI, MISO, and Slave Select to specify that the given signal is not used and therefore does not need to be connected to a pin.
#define	NRF_DRV_SPI_DEFAULT_CONFIG
	SPI master instance default configuration. More...
#define	NRF_DRV_SPI_FLAG_TX_POSTINC   (1UL << 0)
#define	NRF_DRV_SPI_FLAG_RX_POSTINC   (1UL << 1)
#define	NRF_DRV_SPI_FLAG_NO_XFER_EVT_HANDLER   (1UL << 2)
#define	NRF_DRV_SPI_FLAG_HOLD_XFER   (1UL << 3)
#define	NRF_DRV_SPI_FLAG_REPEATED_XFER   (1UL << 4)
#define	NRF_DRV_SPI_SINGLE_XFER(p_tx, tx_len, p_rx, rx_len)
	Macro for setting up single transfer descriptor. More...
#define	NRF_DRV_SPI_XFER_TRX(p_tx_buf, tx_length, p_rx_buf, rx_length)   NRF_DRV_SPI_SINGLE_XFER(p_tx_buf, tx_length, p_rx_buf, rx_length)
	Macro for setting duplex TX RX transfer.
#define	NRF_DRV_SPI_XFER_TX(p_buf, length)   NRF_DRV_SPI_SINGLE_XFER(p_buf, length, NULL, 0)
	Macro for setting TX transfer.
#define	NRF_DRV_SPI_XFER_RX(p_buf, length)   NRF_DRV_SPI_SINGLE_XFER(NULL, 0, p_buf, length)
	Macro for setting RX transfer.

Typedefs
typedef void(*	nrf_drv_spi_handler_t )(nrf_drv_spi_evt_t const *p_event)
	SPI master driver event handler type.

Enumerations
enum	nrf_drv_spi_frequency_t {   NRF_DRV_SPI_FREQ_125K = NRF_SPI_FREQ_125K,   NRF_DRV_SPI_FREQ_250K = NRF_SPI_FREQ_250K,   NRF_DRV_SPI_FREQ_500K = NRF_SPI_FREQ_500K,   NRF_DRV_SPI_FREQ_1M = NRF_SPI_FREQ_1M,   NRF_DRV_SPI_FREQ_2M = NRF_SPI_FREQ_2M,   NRF_DRV_SPI_FREQ_4M = NRF_SPI_FREQ_4M,   NRF_DRV_SPI_FREQ_8M = NRF_SPI_FREQ_8M }
	SPI data rates. More...
enum	nrf_drv_spi_mode_t {   NRF_DRV_SPI_MODE_0 = NRF_SPI_MODE_0,   NRF_DRV_SPI_MODE_1 = NRF_SPI_MODE_1,   NRF_DRV_SPI_MODE_2 = NRF_SPI_MODE_2,   NRF_DRV_SPI_MODE_3 = NRF_SPI_MODE_3 }
	SPI modes. More...
enum	nrf_drv_spi_bit_order_t {   NRF_DRV_SPI_BIT_ORDER_MSB_FIRST = NRF_SPI_BIT_ORDER_MSB_FIRST,   NRF_DRV_SPI_BIT_ORDER_LSB_FIRST = NRF_SPI_BIT_ORDER_LSB_FIRST }
	SPI bit orders. More...
enum	nrf_drv_spi_evt_type_t { NRF_DRV_SPI_EVENT_DONE }
	SPI master driver event types, passed to the handler routine provided during initialization. More...

Functions
ret_code_t	nrf_drv_spi_init (nrf_drv_spi_t const *const p_instance, nrf_drv_spi_config_t const *p_config, nrf_drv_spi_handler_t handler)
	Function for initializing the SPI master driver instance. More...
void	nrf_drv_spi_uninit (nrf_drv_spi_t const *const p_instance)
	Function for uninitializing the SPI master driver instance. More...
ret_code_t	nrf_drv_spi_transfer (nrf_drv_spi_t const *const p_instance, uint8_t const *p_tx_buffer, uint8_t tx_buffer_length, uint8_t *p_rx_buffer, uint8_t rx_buffer_length)
	Function for starting the SPI data transfer. More...
ret_code_t	nrf_drv_spi_xfer (nrf_drv_spi_t const *const p_instance, nrf_drv_spi_xfer_desc_t const *p_xfer_desc, uint32_t flags)
	Function for starting the SPI data transfer with additional option flags. More...
uint32_t	nrf_drv_spi_start_task_get (nrf_drv_spi_t const *p_instance)
	Function for returning the address of a SPIM start task. More...
uint32_t	nrf_drv_spi_end_event_get (nrf_drv_spi_t const *p_instance)
	Function for returning the address of a END SPIM event. More...

Detailed Description

Multi-instance SPI master driver.

Macro Definition Documentation

#define NRF_DRV_SPI_DEFAULT_CONFIG

Value:

{ \
 .sck_pin = NRF_DRV_SPI_PIN_NOT_USED, \
 .mosi_pin = NRF_DRV_SPI_PIN_NOT_USED, \
 .miso_pin = NRF_DRV_SPI_PIN_NOT_USED, \
 .ss_pin = NRF_DRV_SPI_PIN_NOT_USED, \
 .irq_priority = SPI_DEFAULT_CONFIG_IRQ_PRIORITY, \
 .orc = 0xFF, \
 .frequency = NRF_DRV_SPI_FREQ_4M, \
 .mode = NRF_DRV_SPI_MODE_0, \
 .bit_order = NRF_DRV_SPI_BIT_ORDER_MSB_FIRST, \
}

SPI master instance default configuration.

#define NRF_DRV_SPI_FLAG_HOLD_XFER   (1UL << 3)

Set up the transfer but do not start it.

#define NRF_DRV_SPI_FLAG_NO_XFER_EVT_HANDLER   (1UL << 2)

Interrupt after each transfer is suppressed, and the event handler is not called.

#define NRF_DRV_SPI_FLAG_REPEATED_XFER   (1UL << 4)

Flag indicating that the transfer will be executed multiple times.

#define NRF_DRV_SPI_FLAG_RX_POSTINC   (1UL << 1)

RX buffer address incremented after transfer.

#define NRF_DRV_SPI_FLAG_TX_POSTINC   (1UL << 0)

TX buffer address incremented after transfer.

#define NRF_DRV_SPI_INSTANCE

(

id

)

Value:

{ \
 .p_registers = NRF_DRV_SPI_PERIPHERAL(id), \
 .irq = CONCAT_3(SPI, id, _IRQ), \
 .drv_inst_idx = CONCAT_3(SPI, id, _INSTANCE_INDEX), \
 .use_easy_dma = CONCAT_3(SPI, id, _USE_EASY_DMA) \
}

Macro for creating an SPI master driver instance.

#define NRF_DRV_SPI_SINGLE_XFER	(		p_tx,
			tx_len,
			p_rx,
			rx_len
	)

Value:

{ \
 .p_tx_buffer = (uint8_t const *)(p_tx), \
 .tx_length = (tx_len), \
 .p_rx_buffer = (p_rx), \
 .rx_length = (rx_len), \
 }

Macro for setting up single transfer descriptor.

This macro is for internal use only.

Enumeration Type Documentation

enum nrf_drv_spi_bit_order_t

SPI bit orders.

Enumerator
NRF_DRV_SPI_BIT_ORDER_MSB_FIRST	Most significant bit shifted out first.
NRF_DRV_SPI_BIT_ORDER_LSB_FIRST	Least significant bit shifted out first.

enum nrf_drv_spi_evt_type_t

SPI master driver event types, passed to the handler routine provided during initialization.

Enumerator
NRF_DRV_SPI_EVENT_DONE	Transfer done.

enum nrf_drv_spi_frequency_t

SPI data rates.

Enumerator
NRF_DRV_SPI_FREQ_125K	125 kbps.
NRF_DRV_SPI_FREQ_250K	250 kbps.
NRF_DRV_SPI_FREQ_500K	500 kbps.
NRF_DRV_SPI_FREQ_1M	1 Mbps.
NRF_DRV_SPI_FREQ_2M	2 Mbps.
NRF_DRV_SPI_FREQ_4M	4 Mbps.
NRF_DRV_SPI_FREQ_8M	8 Mbps.

enum nrf_drv_spi_mode_t

SPI modes.

Enumerator
NRF_DRV_SPI_MODE_0	SCK active high, sample on leading edge of clock.
NRF_DRV_SPI_MODE_1	SCK active high, sample on trailing edge of clock.
NRF_DRV_SPI_MODE_2	SCK active low, sample on leading edge of clock.
NRF_DRV_SPI_MODE_3	SCK active low, sample on trailing edge of clock.

Function Documentation

uint32_t nrf_drv_spi_end_event_get

(

nrf_drv_spi_t const *

p_instance

)

Function for returning the address of a END SPIM event.

A END event can be used to detect the end of a transfer if the NRF_DRV_SPI_FLAG_NO_XFER_EVT_HANDLER option is used.

Parameters

[in]

p_instance

Pointer to the driver instance structure.

Returns

END event address.

ret_code_t nrf_drv_spi_init	(	nrf_drv_spi_t const *const	p_instance,
		nrf_drv_spi_config_t const *	p_config,
		nrf_drv_spi_handler_t	handler
	)

Function for initializing the SPI master driver instance.

This function configures and enables the specified peripheral.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_config	Pointer to the structure with the initial configuration. If NULL, the default configuration is used.
	handler	Event handler provided by the user. If NULL, transfers will be performed in blocking mode.

Return values

NRF_SUCCESS	If initialization was successful.
NRF_ERROR_INVALID_STATE	If the driver was already initialized.
NRF_ERROR_BUSY	If some other peripheral with the same instance ID is already in use. This is possible only if PERIPHERAL_RESOURCE_SHARING_ENABLED is set to a value other than zero.

uint32_t nrf_drv_spi_start_task_get

(

nrf_drv_spi_t const *

p_instance

)

Function for returning the address of a SPIM start task.

This function should be used if nrf_drv_spi_xfer was called with the flag NRF_DRV_SPI_FLAG_HOLD_XFER. In that case, the transfer is not started by the driver, but it must be started externally by PPI.

Parameters

[in]

p_instance

Pointer to the driver instance structure.

Returns

Start task address.

ret_code_t nrf_drv_spi_transfer	(	nrf_drv_spi_t const *const	p_instance,
		uint8_t const *	p_tx_buffer,
		uint8_t	tx_buffer_length,
		uint8_t *	p_rx_buffer,
		uint8_t	rx_buffer_length
	)

Function for starting the SPI data transfer.

If an event handler was provided in the nrf_drv_spi_init call, this function returns immediately and the handler is called when the transfer is done. Otherwise, the transfer is performed in blocking mode, which means that this function returns when the transfer is finished.

Note

Peripherals using EasyDMA (for example, SPIM) require the transfer buffers to be placed in the Data RAM region. If they are not and an SPIM instance is used, this function will fail with the error code NRF_ERROR_INVALID_ADDR.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_tx_buffer	Pointer to the transmit buffer. Can be NULL if there is nothing to send.
	tx_buffer_length	Length of the transmit buffer.
[in]	p_rx_buffer	Pointer to the receive buffer. Can be NULL if there is nothing to receive.
	rx_buffer_length	Length of the receive buffer.

Return values

NRF_SUCCESS	If the operation was successful.
NRF_ERROR_BUSY	If a previously started transfer has not finished yet.
NRF_ERROR_INVALID_ADDR	If the provided buffers are not placed in the Data RAM region.

void nrf_drv_spi_uninit

(

nrf_drv_spi_t const *const

p_instance

)

Function for uninitializing the SPI master driver instance.

Parameters

[in]

p_instance

Pointer to the driver instance structure.

ret_code_t nrf_drv_spi_xfer	(	nrf_drv_spi_t const *const	p_instance,
		nrf_drv_spi_xfer_desc_t const *	p_xfer_desc,
		uint32_t	flags
	)

Function for starting the SPI data transfer with additional option flags.

Function enables customizing the transfer by using option flags.

Additional options are provided using the flags parameter:

• NRF_DRV_SPI_FLAG_TX_POSTINC and NRF_DRV_SPI_FLAG_RX_POSTINC: Post-incrementation of buffer addresses. Supported only by SPIM.
• NRF_DRV_SPI_FLAG_HOLD_XFER: Driver is not starting the transfer. Use this flag if the transfer is triggered externally by PPI. Supported only by SPIM. Use nrf_drv_twi_start_task_get to get the address of the start task.
• NRF_DRV_SPI_FLAG_NO_XFER_EVT_HANDLER: No user event handler after transfer completion. This also means no interrupt at the end of the transfer. Supported only by SPIM. If NRF_DRV_SPI_FLAG_NO_XFER_EVT_HANDLER is used, the driver does not set the instance into busy state, so you must ensure that the next transfers are set up when SPIM is not active. nrf_drv_spi_end_event_get function can be used to detect end of transfer. Option can be used together with NRF_DRV_SPI_FLAG_REPEATED_XFER to prepare a sequence of SPI transfers without interruptions.
• NRF_DRV_SPI_FLAG_REPEATED_XFER: Prepare for repeated transfers. You can set up a number of transfers that will be triggered externally (for example by PPI). An example is a TXRX transfer with the options NRF_DRV_SPI_FLAG_RX_POSTINC, NRF_DRV_SPI_FLAG_NO_XFER_EVT_HANDLER, and NRF_DRV_SPI_FLAG_REPEATED_XFER. After the transfer is set up, a set of transfers can be triggered by PPI that will read, for example, the same register of an external component and put it into a RAM buffer without any interrupts. nrf_drv_spi_end_event_get can be used to get the address of the END event, which can be used to count the number of transfers. If NRF_DRV_SPI_FLAG_REPEATED_XFER is used, the driver does not set the instance into busy state, so you must ensure that the next transfers are set up when SPIM is not active. Supported only by SPIM.

  Note

  Function is intended to be used only in non-blocking mode.

  Parameters

  p_instance	Pointer to the driver instance structure.
  p_xfer_desc	Pointer to the transfer descriptor.
  flags	Transfer options (0 for default settings).

  Return values

  NRF_SUCCESS	If the procedure was successful.
  NRF_ERROR_BUSY	If the driver is not ready for a new transfer.
  NRF_ERROR_NOT_SUPPORTED	If the provided parameters are not supported.
  NRF_ERROR_INVALID_ADDR	If the provided buffers are not placed in the Data RAM region.