TWI slave APIs. More...

Modules
	TWIS peripheral driver configuration

Data Structures
struct	nrf_drv_twis_t
	TWIS driver instance structure. More...

struct	nrf_drv_twis_evt_t
	TWIS driver event structure. More...

struct	nrf_drv_twis_config_t
	Structure for TWIS configuration. More...

Macros
#define	NRF_DRV_TWIS_INSTANCE_x (id)

#define	NRF_DRV_TWIS_INSTANCE (id) NRF_DRV_TWIS_INSTANCE_x(id)
	Macro for creating TWIS driver instance. More...

#define	TWIS0_INSTANCE_INDEX 0

#define	TWIS1_INSTANCE_INDEX TWIS0_INSTANCE_INDEX+ TWIS0_ENABLED

#define	NRF_DRV_TWIS_DEFAULT_CONFIG
	Generate default configuration for TWIS driver instance. More...

Typedefs
typedef void(*	nrf_drv_twis_event_handler_t )( nrf_drv_twis_evt_t const *const p_event)
	TWI slave event callback function type. More...

Enumerations
enum	nrf_drv_twis_evt_type_t { TWIS_EVT_READ_REQ , TWIS_EVT_READ_DONE , TWIS_EVT_READ_ERROR , TWIS_EVT_WRITE_REQ , TWIS_EVT_WRITE_DONE , TWIS_EVT_WRITE_ERROR , TWIS_EVT_GENERAL_ERROR }
	Event callback function event definitions. More...

enum	nrf_drv_twis_error_t { NRF_DRV_TWIS_ERROR_OVERFLOW = NRF_TWIS_ERROR_OVERFLOW, NRF_DRV_TWIS_ERROR_DATA_NACK = NRF_TWIS_ERROR_DATA_NACK, NRF_DRV_TWIS_ERROR_OVERREAD = NRF_TWIS_ERROR_OVERREAD, NRF_DRV_TWIS_ERROR_UNEXPECTED_EVENT = 1 << 8 }
	Possible error sources. More...

Functions
ret_code_t	nrf_drv_twis_init ( nrf_drv_twis_t const const p_instance, nrf_drv_twis_config_t const p_config, nrf_drv_twis_event_handler_t const event_handler)
	Function for initializing the TWIS driver instance. More...

void	nrf_drv_twis_uninit ( nrf_drv_twis_t const *const p_instance)
	Function for uninitializing the TWIS driver instance. More...

void	nrf_drv_twis_enable ( nrf_drv_twis_t const *const p_instance)
	Enable TWIS instance. More...

void	nrf_drv_twis_disable ( nrf_drv_twis_t const *const p_instance)
	Disable TWIS instance. More...

uint32_t	nrf_drv_twis_error_get_and_clear ( nrf_drv_twis_t const *const p_instance)
	Get and clear last error flags. More...

ret_code_t	nrf_drv_twis_tx_prepare ( nrf_drv_twis_t const const p_instance, void const const p_buf, size_t size)
	Prepare data for sending. More...

size_t	nrf_drv_twis_tx_amount ( nrf_drv_twis_t const *const p_instance)
	Get number of transmitted bytes. More...

ret_code_t	nrf_drv_twis_rx_prepare ( nrf_drv_twis_t const const p_instance, void const p_buf, size_t size)
	Prepare data for receiving. More...

size_t	nrf_drv_twis_rx_amount ( nrf_drv_twis_t const *const p_instance)
	Get number of received bytes. More...

bool	nrf_drv_twis_is_busy ( nrf_drv_twis_t const *const p_instance)
	Function checks if driver is busy right now. More...

bool	nrf_drv_twis_is_waiting_tx_buff ( nrf_drv_twis_t const *const p_instance)
	Function checks if driver is waiting for tx buffer. More...

bool	nrf_drv_twis_is_waiting_rx_buff ( nrf_drv_twis_t const *const p_instance)
	Function checks if driver is waiting for rx buffer. More...

bool	nrf_drv_twis_is_pending_tx ( nrf_drv_twis_t const *const p_instance)
	Check if driver is sending data. More...

bool	nrf_drv_twis_is_pending_rx ( nrf_drv_twis_t const *const p_instance)
	Check if driver is receiving data. More...

Detailed Description

TWI slave APIs.

Macro Definition Documentation

#define NRF_DRV_TWIS_DEFAULT_CONFIG

Value:

         { \
        
         .addr               = {
         
          TWIS_DEFAULT_CONFIG_ADDR0
         
         ,
         
          TWIS_DEFAULT_CONFIG_ADDR1
         
         }, \
        
         .scl                = 31, \
        
         .scl_pull           = (
         
          nrf_gpio_pin_pull_t
         
         )
         
          TWIS_DEFAULT_CONFIG_SCL_PULL
         
         , \
        
         .sda                = 31, \
        
         .sda_pull           = (
         
          nrf_gpio_pin_pull_t
         
         )
         
          TWIS_DEFAULT_CONFIG_SDA_PULL
         
         , \
        
         .interrupt_priority =
         
          TWIS_DEFAULT_CONFIG_IRQ_PRIORITY
         
         \
        
         }

Generate default configuration for TWIS driver instance.

#define NRF_DRV_TWIS_INSTANCE ( id ) NRF_DRV_TWIS_INSTANCE_x(id)

Macro for creating TWIS driver instance.

Parameters

[in] id Instance index. Use 0 for TWIS0 and 1 for TWIS1

#define NRF_DRV_TWIS_INSTANCE_x ( id )

Value:

         { \
        
         TWIS##
         
          id
         
         ##_INSTANCE_INDEX \
        
         }

Typedef Documentation

typedef void(* nrf_drv_twis_event_handler_t)( nrf_drv_twis_evt_t const *const p_event)

TWI slave event callback function type.

Parameters

[in] p_event Event information structure.

Enumeration Type Documentation

enum nrf_drv_twis_error_t

Possible error sources.

This is flag enum - values from this enum can be connected using logical or operator.

Note: We could use directly nrf_twis_error_t . Error type enum is redefined here becouse of possible future extension (eg. supporting timeouts and synchronous mode).

Enumerator
NRF_DRV_TWIS_ERROR_OVERFLOW	RX buffer overflow detected, and prevented
NRF_DRV_TWIS_ERROR_DATA_NACK	NACK sent after receiving a data byte
NRF_DRV_TWIS_ERROR_OVERREAD	TX buffer over-read detected, and prevented
NRF_DRV_TWIS_ERROR_UNEXPECTED_EVENT	Unexpected event detected by state machine

enum nrf_drv_twis_evt_type_t

Event callback function event definitions.

Enumerator
TWIS_EVT_READ_REQ	Read request detected. If there is no buffer prepared, buf_req flag in the even will be set. Call then nrf_drv_twis_tx_prepare to give parameters for buffer.
TWIS_EVT_READ_DONE	Read request has finished - free any data.
TWIS_EVT_READ_ERROR	Read request finished with error.
TWIS_EVT_WRITE_REQ	Write request detected. If there is no buffer prepared, buf_req flag in the even will be set. Call then nrf_drv_twis_rx_prepare to give parameters for buffer.
TWIS_EVT_WRITE_DONE	Write request has finished - process data.
TWIS_EVT_WRITE_ERROR	Write request finished with error.
TWIS_EVT_GENERAL_ERROR	Error that happens not inside WRITE or READ transaction.

Function Documentation

void nrf_drv_twis_disable ( nrf_drv_twis_t const *const p_instance )

Disable TWIS instance.

Disabling TWIS instance gives possibility to turn off the TWIS while holding configuration done by nrf_drv_twis_init

Parameters

p_instance Pointer to the driver instance structure.

void nrf_drv_twis_enable ( nrf_drv_twis_t const *const p_instance )

Enable TWIS instance.

This function enables TWIS instance. Function defined if there is needs for dynamically enabling and disabling the peripheral. Use nrf_drv_twis_enable and nrf_drv_twis_disable functions. They do not change any configuration registers.

Parameters

p_instance Pointer to the driver instance structure.

uint32_t nrf_drv_twis_error_get_and_clear ( nrf_drv_twis_t const *const p_instance )

Get and clear last error flags.

Function gets information about errors. This is also the only possibility to exit from error substate of the internal state machine.

Parameters

[in] p_instance Pointer to the driver instance structure.

Returns: Error flags defined in nrf_drv_twis_error_t

Attention: This function clears error state and flags.

ret_code_t nrf_drv_twis_init	(	nrf_drv_twis_t const *const	p_instance ,
		nrf_drv_twis_config_t const *	p_config ,
		nrf_drv_twis_event_handler_t const	event_handler
	)

Function for initializing the TWIS driver instance.

Function initializes and enables TWIS driver.

Attention: After driver initialization enable it by nrf_drv_twis_enable

Parameters

[in] p_instance Pointer to the driver instance structure.

Attention: p_instance has to be global object. It would be used by interrupts so make it sure that object would not be destroyed when function is leaving.

Parameters

[in]	p_config	Initial configuration.
[in]	event_handler	Event handler provided by the user.

Return values

NRF_SUCCESS	If initialization was successful.
NRF_ERROR_INVALID_STATE	If the driver is 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.

bool nrf_drv_twis_is_busy ( nrf_drv_twis_t const *const p_instance )

Function checks if driver is busy right now.

Actual driver substate is tested. If driver is in any other state than IDLE or ERROR this function returns true.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	Driver is in state other than ERROR or IDLE
false	There is no transmission pending.

bool nrf_drv_twis_is_pending_rx ( nrf_drv_twis_t const *const p_instance )

Check if driver is receiving data.

If this function returns true, it means that there is ongoing input transmission.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	There is ongoing input transmission.
false	Driver is in other state.

bool nrf_drv_twis_is_pending_tx ( nrf_drv_twis_t const *const p_instance )

Check if driver is sending data.

If this function returns true, it means that there is ongoing output transmission.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	There is ongoing output transmission.
false	Driver is in other state.

bool nrf_drv_twis_is_waiting_rx_buff ( nrf_drv_twis_t const *const p_instance )

Function checks if driver is waiting for rx buffer.

If this function returns true, it means that driver is staled expecting of the nrf_drv_twis_rx_prepare function call.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	Driver waits for nrf_drv_twis_rx_prepare
false	Driver is not in the state where it waits for preparing rx buffer.

bool nrf_drv_twis_is_waiting_tx_buff ( nrf_drv_twis_t const *const p_instance )

Function checks if driver is waiting for tx buffer.

If this function returns true, it means that driver is stalled expecting of the nrf_drv_twis_tx_prepare function call.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	Driver waits for nrf_drv_twis_tx_prepare
false	Driver is not in the state where it waits for preparing tx buffer.

size_t nrf_drv_twis_rx_amount ( nrf_drv_twis_t const *const p_instance )

Get number of received bytes.

Function returns number of bytes received. This function may be called after TWIS_EVT_WRITE_DONE or TWIS_EVT_WRITE_ERROR events.

Parameters

[in] p_instance Pointer to the driver instance structure.

Returns: Number of bytes received.

ret_code_t nrf_drv_twis_rx_prepare	(	nrf_drv_twis_t const *const	p_instance ,
		void *const	p_buf ,
		size_t	size
	)

Prepare data for receiving.

This function should be used in response for TWIS_EVT_WRITE_REQ event.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_buf	Buffer that would be filled with received data

Attention: Receiving buffer has to be placed in RAM.

Parameters

size	Size of the buffer (maximum amount of data to receive)

Return values

NRF_SUCCESS	Preparation finished properly
NRF_ERROR_INVALID_ADDR	Given p_buf is not placed inside the RAM
NRF_ERROR_INVALID_LENGTH	Wrong value in size parameter
NRF_ERROR_INVALID_STATE	Module not initialized or not enabled

size_t nrf_drv_twis_tx_amount ( nrf_drv_twis_t const *const p_instance )

Get number of transmitted bytes.

Function returns number of bytes sent. This function may be called after TWIS_EVT_READ_DONE or TWIS_EVT_READ_ERROR events.

Parameters

[in] p_instance Pointer to the driver instance structure.

Returns: Number of bytes sent.

ret_code_t nrf_drv_twis_tx_prepare	(	nrf_drv_twis_t const *const	p_instance ,
		void const *const	p_buf ,
		size_t	size
	)

Prepare data for sending.

This function should be used in response for TWIS_EVT_READ_REQ event.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_buf	Transmission buffer

Attention: Transmission buffer has to be placed in RAM.

Parameters

size	Maximum number of bytes that master may read from buffer given.

Return values

NRF_SUCCESS	Preparation finished properly
NRF_ERROR_INVALID_ADDR	Given p_buf is not placed inside the RAM
NRF_ERROR_INVALID_LENGTH	Wrong value in size parameter
NRF_ERROR_INVALID_STATE	Module not initialized or not enabled

void nrf_drv_twis_uninit ( nrf_drv_twis_t const *const p_instance )

Function for uninitializing the TWIS driver instance.

Function initializes the peripheral and resets all registers to default values.

Parameters

[in] p_instance Pointer to the driver instance structure.

Note: It is safe to call nrf_drv_twis_uninit even before initialization. Actually nrf_drv_twis_init function calls this function to make sure that TWIS state is known.; If TWIS driver was in uninitialized state before calling this function, selected pins would not be reset to default configuration.

Modules

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation