BLE Connection Sync - Why the need for the peripheral to ASSERT?

[SimonBursten]

in this example:

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/samples/bluetooth/conn_time_sync/README.html

the peripheral has this assert statement when it receives a trigger time

__ASSERT_NO_MSG(params->trigger_time_us_central_clock >
                params->anchor_point_us_central_clock);

        if (!atomic_test_and_set_bit(&last_timed_action_in_use, 0)) {
            memcpy(&last_timed_action, params, sizeof(*params));
            atomic_clear_bit(&last_timed_action_in_use, 0);
        }

It's not clear to me why this is needed? What would cause this? latency issues from the central?

[Jared]

Hi.

This checks that the trigger time which is the agreed upon time to schedule the task isn't happening before the reference time(anchor clock). In other words, ensuring that we haven't advanced past that time yet. Clock drift or latency issues can cause the clocks to be skewed. 

best regards

Jared