> My research group has had some good experiences using products from Endace (
> http://www.endace.com/) for network timing measurement at the ethernet
> level. I don't have a pointer immediately to the work, but if there is
> interest can ask tomorrow at work. The gist of it though was to understa
I'm an applications engineer for a company that makes Ethernet controllers
and PHYs. Some of our customers use crystals (more often oscillators) that
they selected based on price rather than performance. when i'm debugging a
customer issue replacing the clock source with a synthesizer is a good
tro
On Sun, Dec 2, 2012 at 3:16 PM, Magnus Danielson wrote:
> Erich,
>
>
> On 12/02/2012 08:54 PM, Erich Heine wrote:
>
>> Jonathan,
>>
>> My research group has had some good experiences using products from
>> Endace (
>> http://www.endace.com/) for network timing measurement at the ethernet
>> level
Matt,
On 12/02/2012 11:51 PM, Matt Davis wrote:
Date: Sun, 02 Dec 2012 22:16:52 +0100
From: Magnus Danielson
On 12/02/2012 08:54 PM, Erich Heine wrote:
Examining the time "in switch" for various packets at the microsecond level
was needed to understand various delay curves for different networ
> Date: Sun, 02 Dec 2012 22:16:52 +0100
> From: Magnus Danielson
>
> On 12/02/2012 08:54 PM, Erich Heine wrote:
>> Examining the time "in switch" for various packets at the microsecond level
>> was needed to understand various delay curves for different network loads,
>> with an ultimate goal of p
Erich,
On 12/02/2012 08:54 PM, Erich Heine wrote:
Jonathan,
My research group has had some good experiences using products from Endace (
http://www.endace.com/) for network timing measurement at the ethernet
level. I don't have a pointer immediately to the work, but if there is
interest can ask
Jonathan,
My research group has had some good experiences using products from Endace (
http://www.endace.com/) for network timing measurement at the ethernet
level. I don't have a pointer immediately to the work, but if there is
interest can ask tomorrow at work. The gist of it though was to under
Hi
Strange - I must indeed have been lucky on the last dozen or so systems I built
up.
Bob
On Dec 2, 2012, at 1:14 PM, David wrote:
> On Sun, 2 Dec 2012 08:43:39 -0500, Bob Camp wrote:
>
>> Hi
>>
>> Maybe I'm just shopping in the right places. I have yet to build up a
>> desktop machine t
On Sun, 2 Dec 2012 08:43:39 -0500, Bob Camp wrote:
>Hi
>
>Maybe I'm just shopping in the right places. I have yet to build up a desktop
>machine that does *not* have at least one COM port on the motherboard. That's
>been true all the way from simple little Atom based ITX boards right through
>
Hi
Maybe I'm just shopping in the right places. I have yet to build up a desktop
machine that does *not* have at least one COM port on the motherboard. That's
been true all the way from simple little Atom based ITX boards right through
monster boards with all sorts of crazy stuff on them. Yes,
On Sat, 01 Dec 2012 19:10:54 -0800, Hal Murray
wrote:
>davidwh...@gmail.com said:
>> One of my favorite tricks back when the ISA bus was still available was to
>> use a custom expansion board I built and an oscilloscope to measure the
>> interrupt latency.
>
>You can do the same trick without sp
davidwh...@gmail.com said:
> One of my favorite tricks back when the ISA bus was still available was to
> use a custom expansion board I built and an oscilloscope to measure the
> interrupt latency.
You can do the same trick without special hardware. Use the printer port.
Of course, that assu
On Sun, 02 Dec 2012 01:53:07 +0100, Magnus Danielson
wrote:
>On 12/02/2012 01:29 AM, David wrote:
>> Originally the IBM PC design used an 8253 or 8254 PIT, programmable
>> interval timer, located at ports 40h to 43h with Timer 0 clocked at
>> 1.193182 MHz (1/3rd of 3.579545 MHz or 1/12th of 14.31
On 12/02/2012 01:29 AM, David wrote:
Originally the IBM PC design used an 8253 or 8254 PIT, programmable
interval timer, located at ports 40h to 43h with Timer 0 clocked at
1.193182 MHz (1/3rd of 3.579545 MHz or 1/12th of 14.318 MHz) and set
to divide by 65536 which generated about an 18.2 Hz int
Originally the IBM PC design used an 8253 or 8254 PIT, programmable
interval timer, located at ports 40h to 43h with Timer 0 clocked at
1.193182 MHz (1/3rd of 3.579545 MHz or 1/12th of 14.318 MHz) and set
to divide by 65536 which generated about an 18.2 Hz interrupt rate on
IRQ 0. Timer 1 generate
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Hash: SHA1
Eric, your experiences here is of great interest to me too, I've been
exploring external clocking of Ethernet controllers as of late but
have not dived into it yet.
I'm more interested in your how, but of course also in your why.
// jwalck
PS. Hey e
: Friday, November 30, 2012 5:10 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Using a frequency synthesizer replacement for
motherboard oscillator
On 11/30/2012 6:30 PM, Eric Garner wrote:
the actual RTC on modern (Intel based) PC's is driven from a s
In message , Bob Camp writes:
>It's most commonly done with things like a Soekris 45xx series board. You
>don't need anything very exotic for the frequency conversion. The jitter in
>the PC is way worse than what the external chips will be creating.
Actually that is _not_ true anymore.
On Fri, Nov 30, 2012 at 8:39 PM, David I. Emery wrote:
> On Fri, Nov 30, 2012 at 09:58:29PM -0500, Bob Camp wrote:
> > Hi
> >
>
> > The problem just the clock it's also the operating system. If it's not
> > designed with timing in mind (= it's an RTOS at some level) then you
> > will have sloppy t
On Fri, Nov 30, 2012 at 09:58:29PM -0500, Bob Camp wrote:
> Hi
>
> The problem just the clock it's also the operating system. If it's not
> designed with timing in mind (= it's an RTOS at some level) then you
> will have sloppy timing. Counters can help, but they are not the entire
> solution. If
Hi
The problem just the clock it's also the operating system. If it's not designed
with timing in mind (= it's an RTOS at some level) then you will have sloppy
timing. Counters can help, but they are not the entire solution. If your email
(or anti-virus or ...) program can pop up and monopolize
On Fri, Nov 30, 2012 at 04:24:38PM -0600, shali...@gmail.com wrote:
> I am not sure that a precision clock will help if the cpu is busy and skips
> clock cycles. I believe this is one of the problems with general purpose OSes
> like Windows.
>
> I believe the better boards like the Soekis use ha
On 11/30/2012 7:54 PM, John Ackermann N8UR wrote:
> On Nov 30, 2012, at 7:10 PM, Sarah White wrote:
>
>> On 11/30/2012 6:30 PM, Eric Garner wrote:
>>> the actual RTC on modern (Intel based) PC's is driven from a standard
>>> 32,768 Hz crystal attached to the PCH. some of them are in incredibly sm
On 11/30/12 4:58 PM, John Ackermann N8UR wrote:
On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR wrote:
In this case, you're not looking for the RTC but rather the clock that drives
the COU
Read "CPU". Stupid iPad keyboard.
I was wondering.. Clock Oscillator Unit? Cryptic Obfuscated Un
OK, I'll bite. Why?
Jim
>>>I've never done it using to the RTC crystal, but I do it quite
frequently in my Day Job to >>>Ethernet controllers on those same pc mother
boards.
>>>
>>>-Eric
On Fri, Nov 30, 2012 at 4:10 PM, Sarah White wrote:
> On 11/30/2012 6:30 PM, Eric Garner wrote:
> > the a
On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR wrote:
> In this case, you're not looking for the RTC but rather the clock that drives
> the COU
Read "CPU". Stupid iPad keyboard.
___
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On Nov 30, 2012, at 7:10 PM, Sarah White wrote:
> On 11/30/2012 6:30 PM, Eric Garner wrote:
>> the actual RTC on modern (Intel based) PC's is driven from a standard
>> 32,768 Hz crystal attached to the PCH. some of them are in incredibly small
>> packages now instead of the old tuning fork-in-a-c
In this case, you're not looking for the RTC but rather the clock that drives
the COU, which is what drives the system clock. On most systems, the RTC is
read only at startup and is not used once the system is running.
John
On Nov 30, 2012, at 6:30 PM, Eric Garner wrote:
> the actual RTC on
Hi
In the case of the Soekris, it was not the real time clock that we all played
with. THe clock you fiddle is the CPU clock. The system is running FreeBSD or
Lunix, so it's a cut above a typical embedded system. A RTOS (like Windows CE)
will indeed do a bit better with a good CPU clock. Anythi
I've never done it using to the RTC crystal, but I do it quite frequently
in my Day Job to Ethernet controllers on those same pc mother boards.
-Eric
On Fri, Nov 30, 2012 at 4:10 PM, Sarah White wrote:
> On 11/30/2012 6:30 PM, Eric Garner wrote:
> > the actual RTC on modern (Intel based) PC's
On 11/30/2012 6:30 PM, Eric Garner wrote:
> the actual RTC on modern (Intel based) PC's is driven from a standard
> 32,768 Hz crystal attached to the PCH. some of them are in incredibly small
> packages now instead of the old tuning fork-in-a-can ones. peeling off the
> load caps and crystal from t
the actual RTC on modern (Intel based) PC's is driven from a standard
32,768 Hz crystal attached to the PCH. some of them are in incredibly small
packages now instead of the old tuning fork-in-a-can ones. peeling off the
load caps and crystal from the board would allow you plenty of spaces to
tack
It all depends on what clock your talking about. Any given PC probably has more
than one oscillator onboard.
Generally there will be one for the CPU, one for the display circuitry, and
probably one for the real time clock.
Presuming you are talking about the CPU clock, it should be fairly
strai
Droid Razr 4G LTE wireless tracker.
-Original Message-
From: Sarah White
To: Discussion of precise time and frequency measurement
Sent: Fri, 30 Nov 2012 3:55 PM
Subject: [time-nuts] Using a frequency synthesizer replacement for motherboard
oscillator
Has anyone ever used a TAPR clock
Hi
It's most commonly done with things like a Soekris 45xx series board. You don't
need anything very exotic for the frequency conversion. The jitter in the PC is
way worse than what the external chips will be creating.
The real question is - what is the "magic frequency" on the particular mot
Has anyone ever used a TAPR clock block or other frequency synthesizer
to sort the clock drift / timing problems on a regular computer? I'll
probably end up with a used dell or IBM workstation for this purpose.
Recently, I came across a low-cost frequency synthesizer capable of
using a 10mhz frequ
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