ts-7000
[Top] [All Lists]

[ts-7000] Re: 983.04 Khz timer

To:
Subject: [ts-7000] Re: 983.04 Khz timer
From: "Jesse Off" <>
Date: Tue, 18 Apr 2006 17:14:27 -0000
Don, you could also tweak the value "5085" +/- 1 where it appears in 
the kernel source file ./include/asm-arm/arch-ep93xx/time.h  15 
seconds a day (174PPM) seems excessive.  There is 63 PPM error 
introduced by Linux wanting 100Hz and not being able to generate it 
perfectly, and another 50 PPM crystal spec for 113 PPM (9.7 
seconds/day) total potential error.

NetBSD uses a precise 64Hz clock for timekeeping and in my tests 
drifts a lot less than Linux.  One might be able to change Linux to 
use that 64Hz clock if timing is really critical.

//Jesse Off

> Of course this still does not solve the problem of losing over 15 
seconds
> per day when they want to know to the nearest second when a train 
leaves the
> station.
> 
> Thanks!
> 
> Don.






 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ts-7000/

<*> To unsubscribe from this group, send an email to:
    

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


<Prev in Thread] Current Thread [Next in Thread>
Admin

Disclaimer: Neither Andrew Taylor nor the University of NSW School of Computer and Engineering take any responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU