sd_radio_request()

uint32_t sd_radio_request

(

nrf_radio_request_t const *

p_request

)

#include <nrf_soc.h>

Requests a radio timeslot.

Note

The request type is determined by p_request->request_type, and can be one of NRF_RADIO_REQ_TYPE_EARLIEST and NRF_RADIO_REQ_TYPE_NORMAL. The first request in a session must always be of type NRF_RADIO_REQ_TYPE_EARLIEST.

For a normal request (NRF_RADIO_REQ_TYPE_NORMAL), the start time of a radio timeslot is specified by p_request->distance_us and is given relative to the start of the previous timeslot.

A too small p_request->distance_us will lead to a NRF_EVT_RADIO_BLOCKED event.

Timeslots scheduled too close will lead to a NRF_EVT_RADIO_BLOCKED event.

See the SoftDevice Specification for more on radio timeslot scheduling, distances and lengths.

If an opportunity for the first radio timeslot is not found before nrf_radio_request_earliest_t::timeout_us after the call to this function, it is not scheduled, and instead a NRF_EVT_RADIO_BLOCKED event is sent. The application may then try to schedule the first radio timeslot again.

Successful requests will result in nrf_radio_signal_callback_t(NRF_RADIO_CALLBACK_SIGNAL_TYPE_START). Unsuccessful requests will result in a NRF_EVT_RADIO_BLOCKED event, see NRF_SOC_EVTS.

The jitter in the start time of the radio timeslots is +/- NRF_RADIO_START_JITTER_US us.

The nrf_radio_signal_callback_t(NRF_RADIO_CALLBACK_SIGNAL_TYPE_START) call has a latency relative to the specified radio timeslot start, but this does not affect the actual start time of the timeslot.

SD_TIMESLOT_TIMER0 is reset at the start of the radio timeslot, and is clocked at 1MHz from the high frequency (16 MHz) clock source. If p_request->hfclk_force_xtal is true, the high frequency clock is guaranteed to be clocked from the external crystal.

The SoftDevice will neither access the NRF_RADIO peripheral nor the SD_TIMESLOT_TIMER0 peripheral during the radio timeslot.

Parameters

[in]

p_request

Pointer to the request parameters.

Return values

NRF_ERROR_FORBIDDEN	Either: The session is not open. The session is not IDLE. This is the first request and its type is not NRF_RADIO_REQ_TYPE_EARLIEST. The request type was set to NRF_RADIO_REQ_TYPE_NORMAL after a NRF_RADIO_REQ_TYPE_EARLIEST request was blocked.
NRF_ERROR_INVALID_ADDR	If the p_request pointer is invalid.
NRF_ERROR_INVALID_PARAM	If the parameters of p_request are not valid.
NRF_SUCCESS	Otherwise.