This anomaly applies to IC Rev. Engineering A, build codes SICA-BAA.
Symptoms
LFCLOCK is not precise after reset until LFXO is available.
Conditions
The LFXO is enabled and EVENTS_LFCLKSTARTED not received yet.
Consequences
Imprecise LFCLOCK may lead to system lockup while waiting for the LFXO to become available.
Workaround
Do not enter System ON IDLE in the period between writing TASK_LFCLKSTART= 1 and receiving EVENTS_ LFCLKSTARTED.
The startup time for the LFXO is stated in the electrical parameter t
START_LFXO in
32.768 kHz high accuracy oscillator (LFXO) in nRF9160 Product Specification.
Note: The LTE modem requires LFXO as LFCLK source.