[riot-notifications] [RIOT-OS/RIOT] tests/xtimer_usleep: recognize negative offset (#11493)
notifications at github.com
Tue May 7 15:56:55 CEST 2019
> So in a timesloted networking protocol if I say:
I think we need to keep the timescales in context. I'd expect my timer subsystem to quantize any real time interval to the to the *closest* hardware timer tick instead of always rounding up. That would make it at most +/- half a tick wrong, being spot on on average. Always rounding up would mean it is between 0 and a whole tick *late* (half a tick on average).
Your argumentation for a timeslot would shift the problem to the end of the timeslot (always rounding up might make the protocol exceed its timeslot every time).
In practice, we're talking +- 0-15us vs +0-30us for a 32kHz timer quantized to 1000000us. The better option here is to either work with the low-level ticks or chose a faster timer. Or chose one that corrects in software via spinning, but that is inefficient.
I think we agree that the timer peripheral itself must not sleep too little. Is that the issue here?
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the notifications