[ntp:questions] Re: Linux PPS triggering with NMEA

Brad Knowles brad at stop.mail-abuse.org
Tue May 10 17:57:29 UTC 2005


At 5:29 PM +0000 2005-05-10, Bjorn Gabrielsson wrote:

>  Thanks! I will try that too. Late last night I found rdtscl() and
>  rdtsc(,). Which seem to capture a counter running at CPU speed - ca
>  2.002656 GHz. A 32-bit counter loops around in about 2 seconds! This
>  gives all resolution I was asking about... and more.

	This gives you resolution, but not accuracy.  All that extra 
resolution is garbage noise.  The actual accuracy is still at the 
microsecond level.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.



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