[ntp:questions] Re: Bought a GPS receiver--What next?

Wolfgang S. Rupprecht wolfgang+gnus20041101T201445 at dailyplanet.dontspam.wsrcc.com
Tue Nov 2 04:27:41 UTC 2004


>     Worse, they quote a time accuracy of one microsecond. When I asked them, 
> "one microsecond between what and what?", they ignored me twice. Clearly, 
> it's one microsecond between GPS time and the clock's internal 
> representation of time -- to which you have no access.

I always found that it was sad that the GPS interfaces didn't provide
a simple 64-bit (or better yet 128-bit) cpu accessible register that
simply provided the GPS's current internal time.  The PPS output is a
pretty cumbersome output to try to use.

Does anyone have the ear of any of the GPS chip guys?  Now that
computer buses are turning into high-speed serial buses, would it be
possible to design a low pin-count GPS chip that dropped into the
PCI-e or hypertransport bus and just reported the current time in,
say, nanoseconds (or better yet 2^-32 seconds) since the GPS epoch?

-wolfgang
-- 
Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/



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