S132 SoftDevice v5.0.0-1.alpha
Data Fields
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 xtal_accuracy
 

Detailed Description

Type representing lfclk oscillator source.

Field Documentation

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.
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 +/-250ppm 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.
uint8_t nrf_clock_lf_cfg_t::source

LF oscillator clock source, see Possible lfclk oscillator sources.

uint8_t nrf_clock_lf_cfg_t::xtal_accuracy
 External crystal clock accuracy used in the LL to compute timing windows.
Note
For the NRF_CLOCK_LF_SRC_RC clock source this parameter is ignored.

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