Dear Experts,
I would like to better understand what exactly is accomplished by the mode-0 synchronization in Channel Sounding. My current understanding is that it seems to measure the frequency offset between two devices, and sometimes also transmits the FAE table (although in one response, an expert mentioned that Nordic does not require this：nRF54L15 Channel sounding FAE table issue - Nordic Q&A - Nordic DevZone - Nordic DevZone). My question is: does mode-0 synchronization need to be performed in every subevent? If the FAE is a fixed table for a given device, then for multiple measurements, is it sufficient to complete synchronization in just the first subevent and continue using the already obtained synchronization status for subsequent subevents?
Based on this, I have a second question: can the results measured by mode-0 be accessed and used by my code? For example, could I use the measured frequency offset between two devices for other purposes in my application? Does the synchronization achieved by mode-0 allow the two devices to remain in this state continuously? If I am able to keep the PLL (phase-locked loop) running and avoid turning off the crystal oscillator, is it possible for the two devices to maintain their synchronized state over time?
I also noticed a register called CSTONE.PCT, which seems to correspond to the phase correction process defined in the protocol. Is it possible that the value of this register represents the measured frequency offset between the two devices? I am not sure if my understanding is correct.
Best regards,
Cheng