nrf_clock_lf_cfg_t Struct Reference

Type representing LFCLK oscillator source. More...

#include <nrf_sdm.h>

Data Fields
uint8_t	source
uint8_t	rc_ctiv
uint8_t	rc_temp_ctiv
uint8_t	accuracy

Detailed Description

Type representing LFCLK oscillator source.

Definition at line 217 of file nrf_sdm.h.

Field Documentation

uint8_t nrf_clock_lf_cfg_t::accuracy

External clock accuracy used in the LL to compute timing windows, see Clock accuracy.

Definition at line 245 of file nrf_sdm.h.

uint8_t nrf_clock_lf_cfg_t::rc_ctiv

Only for NRF_CLOCK_LF_SRC_RC: Calibration timer interval in 1/4 second units (nRF51: 1-64, nRF52: 1-32).

Note

To avoid excessive clock drift, 0.5 degrees Celsius is the maximum temperature change allowed in one calibration timer interval. The interval should be selected to ensure this.

Must be 0 if source is not NRF_CLOCK_LF_SRC_RC.

Definition at line 220 of file nrf_sdm.h.

uint8_t nrf_clock_lf_cfg_t::rc_temp_ctiv

Only for NRF_CLOCK_LF_SRC_RC: How often (in number of calibration intervals) the RC oscillator shall be calibrated if the temperature hasn't changed. 0: Always calibrate even if the temperature hasn't changed. 1: Only calibrate if the temperature has changed (nRF51 only). 2-33: Check the temperature and only calibrate if it has changed, however calibration will take place every rc_temp_ctiv intervals in any case.

Note

Must be 0 if source is not NRF_CLOCK_LF_SRC_RC.

For nRF52, the application must ensure calibration at least once every 8 seconds to ensure +/-250 ppm clock stability. The recommended configuration for NRF_CLOCK_LF_SRC_RC on nRF52 is rc_ctiv=16 and rc_temp_ctiv=2. This will ensure calibration at least once every 8 seconds and for temperature changes of 0.5 degrees Celsius every 4 seconds. See the Product Specification for the nRF52 device being used for more information.

Definition at line 227 of file nrf_sdm.h.

uint8_t nrf_clock_lf_cfg_t::source

LF oscillator clock source, see Possible LFCLK oscillator sources.

Definition at line 219 of file nrf_sdm.h.

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The documentation for this struct was generated from the following file:

• nrf_sdm.h