UARTE driver¶

group nrfx_uarte

UARTE peripheral driver.

Defines

NRFX_UARTE_INSTANCE(id)¶: Macro for creating a UARTE driver instance.

NRFX_UARTE_DEFAULT_EXTENDED_STOP_CONFIG¶: UARTE additional stop bits configuration.

NRFX_UARTE_DEFAULT_EXTENDED_PARITYTYPE_CONFIG¶: UARTE additional parity type configuration.

NRFX_UARTE_DEFAULT_CONFIG(_pin_tx, _pin_rx)¶

UARTE driver default configuration.

This configuration sets up UARTE with the following options:

hardware flow control disabled
no parity bit
one stop bit
baudrate: 115200

Parameters

_pin_tx – [in] TX pin.
_pin_rx – [in] RX pin.

Typedefs

typedef void (*nrfx_uarte_event_handler_t)(nrfx_uarte_event_t const *p_event, void *p_context)¶

UARTE interrupt event handler.

Parameters

p_event – [in] Pointer to event structure. Event is allocated on the stack so it is available only within the context of the event handler.
p_context – [in] Context passed to the interrupt handler, set on initialization.

Enums

enum nrfx_uarte_evt_type_t¶

Types of UARTE driver events.

Values:

enumerator NRFX_UARTE_EVT_TX_DONE¶: Requested TX transfer completed.

enumerator NRFX_UARTE_EVT_RX_DONE¶: Requested RX transfer completed.

enumerator NRFX_UARTE_EVT_ERROR¶: Error reported by UART peripheral.

Functions

nrfx_err_t nrfx_uarte_init(nrfx_uarte_t const *p_instance, nrfx_uarte_config_t const *p_config, nrfx_uarte_event_handler_t event_handler)¶

Function for initializing the UARTE driver.

This function configures and enables UARTE. After this function GPIO pins are controlled by UARTE.

Parameters

p_instance – [in] Pointer to the driver instance structure.
p_config – [in] Pointer to the structure with the initial configuration.
event_handler – [in] Event handler provided by the user. If not provided driver works in blocking mode.

Returns NRFX_SUCCESS

Initialization was successful.

Returns NRFX_ERROR_INVALID_STATE

Driver is already initialized.

Returns NRFX_ERROR_BUSY

Some other peripheral with the same instance ID is already in use. This is possible only if Peripheral Resource Sharing (PRS) module is enabled.

void nrfx_uarte_uninit(nrfx_uarte_t const *p_instance)¶

Function for uninitializing the UARTE driver.

Parameters

p_instance – [in] Pointer to the driver instance structure.

NRFX_STATIC_INLINE uint32_t nrfx_uarte_task_address_get(nrfx_uarte_t const *p_instance, nrf_uarte_task_t task)¶

Function for getting the address of the specified UARTE task.

Parameters

p_instance – [in] Pointer to the driver instance structure.
task – [in] Task.

Returns

Task address.

NRFX_STATIC_INLINE uint32_t nrfx_uarte_event_address_get(nrfx_uarte_t const *p_instance, nrf_uarte_event_t event)¶

Function for getting the address of the specified UARTE event.

Parameters

p_instance – [in] Pointer to the driver instance structure.
event – [in] Event.

Returns

Event address.

nrfx_err_t nrfx_uarte_tx(nrfx_uarte_t const *p_instance, uint8_t const *p_data, size_t length)¶

Function for sending data over UARTE.

If an event handler is provided in nrfx_uarte_init() call, this function returns immediately and the handler is called when the transfer is done. Otherwise, the transfer is performed in blocking mode, that is this function returns when the transfer is finished. Blocking mode is not using interrupt so there is no context switching inside the function.

Note

Peripherals using EasyDMA (including UARTE) require the transfer buffers to be placed in the Data RAM region. If this condition is not met, this function will fail with the error code NRFX_ERROR_INVALID_ADDR.

Parameters

p_instance – [in] Pointer to the driver instance structure.
p_data – [in] Pointer to data.
length – [in] Number of bytes to send. Maximum possible length is dependent on the used SoC (see the MAXCNT register description in the Product Specification). The driver checks it with assertion.

Returns NRFX_SUCCESS

Initialization was successful.

Returns NRFX_ERROR_BUSY

Driver is already transferring.

Returns NRFX_ERROR_FORBIDDEN

The transfer was aborted from a different context (blocking mode only).

Returns NRFX_ERROR_INVALID_ADDR

p_data does not point to RAM buffer.

bool nrfx_uarte_tx_in_progress(nrfx_uarte_t const *p_instance)¶

Function for checking if UARTE is currently transmitting.

Parameters

p_instance – [in] Pointer to the driver instance structure.

Returns true

The UARTE is transmitting.

Returns false

The UARTE is not transmitting.

void nrfx_uarte_tx_abort(nrfx_uarte_t const *p_instance)¶

Function for aborting any ongoing transmission.

Note

NRFX_UARTE_EVT_TX_DONE event will be generated in non-blocking mode. It will contain number of bytes sent until the abort was called. The event handler will be called from the UARTE interrupt context.

Parameters

p_instance – [in] Pointer to the driver instance structure.

nrfx_err_t nrfx_uarte_rx(nrfx_uarte_t const *p_instance, uint8_t *p_data, size_t length)¶

Function for receiving data over UARTE.

If an event handler is provided in the nrfx_uarte_init() call, this function returns immediately and the handler is called when the transfer is done. Otherwise, the transfer is performed in blocking mode, that is this function returns when the transfer is finished. Blocking mode is not using interrupt so there is no context switching inside the function. The receive buffer pointer is double-buffered in non-blocking mode. The secondary buffer can be set immediately after starting the transfer and will be filled when the primary buffer is full. The double-buffering feature allows receiving data continuously.

Note

Peripherals using EasyDMA (including UARTE) require the transfer buffers to be placed in the Data RAM region. If this condition is not met, this function fails with the error code NRFX_ERROR_INVALID_ADDR.

Warning

When the double-buffering feature is used and the UARTE interrupt is processed with a delay (for example, due to a higher priority interrupt) long enough for both buffers to get filled completely, the event handler will be invoked only once, to notify that the first buffer has been filled. This is because from hardware perspective it is impossible to deduce in such case if the second buffer was also filled completely or not. To prevent this from happening, keep the UARTE interrupt latency low or use large enough reception buffers.

Parameters

p_instance – [in] Pointer to the driver instance structure.
p_data – [in] Pointer to data.
length – [in] Number of bytes to receive. Maximum possible length is dependent on the used SoC (see the MAXCNT register description in the Product Specification). The driver checks it with assertion.

Returns NRFX_SUCCESS

Initialization is successful.

Returns NRFX_ERROR_BUSY

The driver is already receiving (and the secondary buffer has already been set in non-blocking mode).

Returns NRFX_ERROR_FORBIDDEN

The transfer is aborted from a different context (blocking mode only).

Returns NRFX_ERROR_INTERNAL

The UARTE peripheral reports an error.

Returns NRFX_ERROR_INVALID_ADDR

p_data does not point to RAM buffer.

bool nrfx_uarte_rx_ready(nrfx_uarte_t const *p_instance)¶

Function for testing the receiver state in blocking mode.

Parameters

p_instance – [in] Pointer to the driver instance structure.

Returns true

The receiver has at least one byte of data to get.

Returns false

The receiver is empty.

void nrfx_uarte_rx_abort(nrfx_uarte_t const *p_instance)¶

Function for aborting any ongoing reception.

Note

NRFX_UARTE_EVT_RX_DONE event will be generated in non-blocking mode. It will contain number of bytes received until the abort was called. The event handler will be called from the UARTE interrupt context.

Warning

When the double-buffering feature is used and the UARTE interrupt is processed with a delay (for example, due to a higher priority interrupt) long enough for the first buffer to be filled completely, the event handler will be supplied with the pointer to the first buffer and the number of bytes received in the second buffer. This is because from hardware perspective it is impossible to deduce the reception of which buffer has been aborted. To prevent this from happening, keep the UARTE interrupt latency low or use large enough reception buffers.

Parameters

p_instance – [in] Pointer to the driver instance structure.

uint32_t nrfx_uarte_errorsrc_get(nrfx_uarte_t const *p_instance)¶

Function for reading error source mask. Mask contains values from nrf_uarte_error_mask_t.

Note

Function must be used in the blocking mode only. In case of non-blocking mode, an error event is generated. Function clears error sources after reading.

Parameters

p_instance – [in] Pointer to the driver instance structure.

Returns

Mask of reported errors.

struct nrfx_uarte_t¶

#include <nrfx_uarte.h>

Structure for the UARTE driver instance.

Public Members

NRF_UARTE_Type *p_reg¶: Pointer to a structure with UARTE registers.

uint8_t drv_inst_idx¶: Index of the driver instance. For internal use only.

struct nrfx_uarte_config_t¶

#include <nrfx_uarte.h>

Structure for the UARTE configuration.

Public Members

uint32_t pseltxd¶: TXD pin number.

uint32_t pselrxd¶: RXD pin number.

uint32_t pselcts¶: CTS pin number.

uint32_t pselrts¶: RTS pin number.

void *p_context¶: Context passed to interrupt handler.

nrf_uarte_baudrate_t baudrate¶: Baud rate.

uint8_t interrupt_priority¶: Interrupt priority.

nrf_uarte_config_t hal_cfg¶: Parity, flow control and stop bits settings.

struct nrfx_uarte_xfer_evt_t¶

#include <nrfx_uarte.h>

Structure for the UARTE transfer completion event.

Public Members

uint8_t *p_data¶: Pointer to memory used for transfer.

size_t bytes¶: Number of bytes transfered.

struct nrfx_uarte_error_evt_t¶

#include <nrfx_uarte.h>

Structure for UARTE error event.

Public Members

nrfx_uarte_xfer_evt_t rxtx¶: Transfer details, including number of bytes transferred.

uint32_t error_mask¶: Mask of error flags that generated the event.

struct nrfx_uarte_event_t¶

#include <nrfx_uarte.h>

Structure for UARTE event.

Public Members

nrfx_uarte_evt_type_t type¶: Event type.

nrfx_uarte_xfer_evt_t rxtx¶: Data provided for transfer completion events.

nrfx_uarte_error_evt_t error¶: Data provided for error event.

union nrfx_uarte_event_t.[anonymous] data¶: Union to store event data.