On Tue, May 14, 2013 at 08:10:38PM -0700, Peter Monta wrote: >>> Bulk transfer might work well on a system where nothing else is going >> on, >>> so "best effort" translates to "now".
>> Does it mean "now" or "next polling cycle"? > It means "now", or pretty close. No waiting for > start-of-USB-frame or -microframe. > Herbert mentions that all USB transfers are host-initiated, > which is true (even for the so-called "interrupt" transfers), > but the latency is usually much less than one frame on a > lightly loaded bus I believe. http://www.beyondlogic.org/usbnutshell/usb4.shtml best, Herbert > I agree with Magnus' remark that this is not rocket science. > Maybe it's time for a small proof of principle, using something > like a Teensy board, that takes PPS edges from the outside > world and connects them to USB. > GNSS samplers should be timestamping their packets so that the > relationship between sample number and device-local time (and > ultimately also host time) can be known. > Cheers, > Peter > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
