TWIS HAL

group nrf_twis_hal

Hardware access layer for managing the Two Wire Interface Slave with EasyDMA (TWIS) peripheral.

Typedefs

typedef uint8_t nrf_twis_address_t

Smallest variable type to hold the TWI address.

Variable of the minimum size that can hold a single TWI address.

Note

Defined to make it simple to change if the new TWI supports for example 10 bit addressing mode.

Enums

enum nrf_twis_task_t

TWIS tasks.

Values:

enumerator NRF_TWIS_TASK_STOP: Stop TWIS transaction.

enumerator NRF_TWIS_TASK_SUSPEND: Suspend TWIS transaction.

enumerator NRF_TWIS_TASK_RESUME: Resume TWIS transaction.

enumerator NRF_TWIS_TASK_PREPARERX: Prepare the TWIS slave to respond to a write command.

enumerator NRF_TWIS_TASK_PREPARETX: Prepare the TWIS slave to respond to a read command.

enum nrf_twis_event_t

TWIS events.

Values:

enumerator NRF_TWIS_EVENT_STOPPED: TWIS stopped.

enumerator NRF_TWIS_EVENT_ERROR: TWIS error.

enumerator NRF_TWIS_EVENT_RXSTARTED: Receive sequence started.

enumerator NRF_TWIS_EVENT_TXSTARTED: Transmit sequence started.

enumerator NRF_TWIS_EVENT_WRITE: Write command received.

enumerator NRF_TWIS_EVENT_READ: Read command received.

enum nrf_twis_short_mask_t

TWIS shortcuts.

Values:

enumerator NRF_TWIS_SHORT_WRITE_SUSPEND_MASK: Shortcut between WRITE event and SUSPEND task.

enumerator NRF_TWIS_SHORT_READ_SUSPEND_MASK: Shortcut between READ event and SUSPEND task.

enum nrf_twis_int_mask_t

TWIS interrupts.

Values:

enumerator NRF_TWIS_INT_STOPPED_MASK: Interrupt on STOPPED event.

enumerator NRF_TWIS_INT_ERROR_MASK: Interrupt on ERROR event.

enumerator NRF_TWIS_INT_RXSTARTED_MASK: Interrupt on RXSTARTED event.

enumerator NRF_TWIS_INT_TXSTARTED_MASK: Interrupt on TXSTARTED event.

enumerator NRF_TWIS_INT_WRITE_MASK: Interrupt on WRITE event.

enumerator NRF_TWIS_INT_READ_MASK: Interrupt on READ event.

enum nrf_twis_error_t

TWIS error source.

Values:

enumerator NRF_TWIS_ERROR_OVERFLOW: RX buffer overflow detected, and prevented.

enumerator NRF_TWIS_ERROR_DATA_NACK: NACK sent after receiving a data byte.

enumerator NRF_TWIS_ERROR_OVERREAD: TX buffer over-read detected, and prevented.

enum nrf_twis_config_addr_mask_t

TWIS address matching configuration.

Values:

enumerator NRF_TWIS_CONFIG_ADDRESS0_MASK: Enable or disable address matching on ADDRESS[0].

enumerator NRF_TWIS_CONFIG_ADDRESS1_MASK: Enable or disable address matching on ADDRESS[1].

enumerator NRF_TWIS_CONFIG_ADDRESS01_MASK: Enable both address matching.

Functions

NRF_STATIC_INLINE void nrf_twis_task_trigger(NRF_TWIS_Type *p_reg, nrf_twis_task_t task)

Function for activating the specified TWIS task.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
task – [in] Task to be activated.

NRF_STATIC_INLINE uint32_t nrf_twis_task_address_get(NRF_TWIS_Type const *p_reg, nrf_twis_task_t task)

Function for returning the address of the specified TWIS task register.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
task – [in] The specified task.

Returns

Task address.

NRF_STATIC_INLINE void nrf_twis_event_clear(NRF_TWIS_Type *p_reg, nrf_twis_event_t event)

Function for clearing the specified event.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
event – [in] The specified event.

NRF_STATIC_INLINE bool nrf_twis_event_check(NRF_TWIS_Type const *p_reg, nrf_twis_event_t event)

Function for retrieving the state of the TWIS event.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
event – [in] Event to be checked.

Return values

true – The event has been generated.
false – The event has not been generated.

NRF_STATIC_INLINE bool nrf_twis_event_get_and_clear(NRF_TWIS_Type *p_reg, nrf_twis_event_t event)

Function for getting and clearing the state of the specified event.

This function checks the state of the event and clears it.

Parameters

p_reg – [inout] Pointer to the structure of registers of the peripheral.
event – [in] Event.

Return values

true – The event was set.
false – The event was not set.

NRF_STATIC_INLINE uint32_t nrf_twis_event_address_get(NRF_TWIS_Type const *p_reg, nrf_twis_event_t event)

Function for returning the address of the specified TWIS event register.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
event – [in] Event.

Returns

Address.

NRF_STATIC_INLINE void nrf_twis_shorts_enable(NRF_TWIS_Type *p_reg, uint32_t mask)

Function for setting a shortcut.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
mask – [in] Mask of shortcuts to be enabled.

NRF_STATIC_INLINE void nrf_twis_shorts_disable(NRF_TWIS_Type *p_reg, uint32_t mask)

Function for clearing shortcuts.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
mask – [in] Mask of shortcuts to be disabled.

NRF_STATIC_INLINE uint32_t nrf_twis_shorts_get(NRF_TWIS_Type const *p_reg)

Function for getting the shorts mask.

Function returns shorts register.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

Returns

Flags of currently enabled shortcuts

NRF_STATIC_INLINE void nrf_twis_int_enable(NRF_TWIS_Type *p_reg, uint32_t mask)

Function for enabling the specified interrupts.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
mask – [in] Mask of interrupts to be enabled.

NRF_STATIC_INLINE uint32_t nrf_twis_int_enable_check(NRF_TWIS_Type const *p_reg, uint32_t mask)

Function for checking if the specified interrupts are enabled.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
mask – [in] Mask of interrupts to be checked.

Returns

Mask of enabled interrupts.

NRF_STATIC_INLINE void nrf_twis_int_disable(NRF_TWIS_Type *p_reg, uint32_t mask)

Function for disabling the specified interrupts.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
mask – [in] Mask of interrupts to be disabled.

NRF_STATIC_INLINE void nrf_twis_subscribe_set(NRF_TWIS_Type *p_reg, nrf_twis_task_t task, uint8_t channel)

Function for setting the subscribe configuration for a given TWIS task.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
task – [in] Task for which to set the configuration.
channel – [in] Channel through which to subscribe events.

NRF_STATIC_INLINE void nrf_twis_subscribe_clear(NRF_TWIS_Type *p_reg, nrf_twis_task_t task)

Function for clearing the subscribe configuration for a given TWIS task.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
task – [in] Task for which to clear the configuration.

NRF_STATIC_INLINE void nrf_twis_publish_set(NRF_TWIS_Type *p_reg, nrf_twis_event_t event, uint8_t channel)

Function for setting the publish configuration for a given TWIS event.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
event – [in] Event for which to set the configuration.
channel – [in] Channel through which to publish the event.

NRF_STATIC_INLINE void nrf_twis_publish_clear(NRF_TWIS_Type *p_reg, nrf_twis_event_t event)

Function for clearing the publish configuration for a given TWIS event.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
event – [in] Event for which to clear the configuration.

NRF_STATIC_INLINE uint32_t nrf_twis_error_source_get_and_clear(NRF_TWIS_Type *p_reg)

Function for retrieving and clearing the TWIS error source.

Attention: Error sources are cleared after read.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

Returns

Error source mask with values from nrf_twis_error_t.

NRF_STATIC_INLINE uint_fast8_t nrf_twis_match_get(NRF_TWIS_Type const *p_reg)

Function for getting information about which of the addresses matched.

Function returns index in the address table that points to the address that already matched.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

Returns

Index of matched address.

NRF_STATIC_INLINE void nrf_twis_enable(NRF_TWIS_Type *p_reg)

Function for enabling TWIS.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

NRF_STATIC_INLINE void nrf_twis_disable(NRF_TWIS_Type *p_reg)

Function for disabling TWIS.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

NRF_STATIC_INLINE void nrf_twis_pins_set(NRF_TWIS_Type *p_reg, uint32_t scl, uint32_t sda)

Function for configuring TWIS pins.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
scl – [in] SCL pin number.
sda – [in] SDA pin number.

NRF_STATIC_INLINE uint32_t nrf_twis_scl_pin_get(NRF_TWIS_Type const *p_reg)

Function for retrieving the SCL pin selection.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

Returns

SCL pin selection.

NRF_STATIC_INLINE uint32_t nrf_twis_sda_pin_get(NRF_TWIS_Type const *p_reg)

Function for retrieving the SDA pin selection.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

Returns

SDA pin selection.

NRF_STATIC_INLINE void nrf_twis_rx_buffer_set(NRF_TWIS_Type *p_reg, uint8_t *p_buf, size_t length)

Function for setting the receive buffer.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
p_buf – [in] Pointer to the buffer for received data.
length – [in] Maximum number of data bytes to receive.

NRF_STATIC_INLINE void nrf_twis_rx_prepare(NRF_TWIS_Type *p_reg, uint8_t *p_buf, size_t length)

Function that prepares TWIS for receiving.

This function sets receive buffer and then sets NRF_TWIS_TASK_PREPARERX task.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
p_buf – [in] Pointer to the buffer for received data.
length – [in] Maximum number of data bytes to receive.

NRF_STATIC_INLINE size_t nrf_twis_rx_amount_get(NRF_TWIS_Type const *p_reg)

Function for getting number of bytes received in the last transaction.

Parameters

p_reg – [in] TWIS instance.

Returns

Amount of bytes received.

NRF_STATIC_INLINE void nrf_twis_tx_buffer_set(NRF_TWIS_Type *p_reg, uint8_t const *p_buf, size_t length)

Function for setting the transmit buffer.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
p_buf – [in] Pointer to the buffer with data to send.
length – [in] Maximum number of data bytes to transmit.

NRF_STATIC_INLINE void nrf_twis_tx_prepare(NRF_TWIS_Type *p_reg, uint8_t const *p_buf, size_t length)

Function for preparing TWIS for transmitting.

This function sets transmit buffer and then sets NRF_TWIS_TASK_PREPARETX task.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.
p_buf – [in] Pointer to the buffer with data to send.
length – [in] Maximum number of data bytes to transmit.

NRF_STATIC_INLINE size_t nrf_twis_tx_amount_get(NRF_TWIS_Type const *p_reg)

Function for getting the number of bytes transmitted in the last transaction.

Parameters

p_reg – [in] Pointer to the structure of registers of the peripheral.

Returns

Amount of bytes transmitted.

NRF_STATIC_INLINE void nrf_twis_address_set(NRF_TWIS_Type *p_reg, uint_fast8_t n, nrf_twis_address_t addr)

Function for setting the slave address.

Function sets the selected address for this TWI interface.