[SI-LIST] Gigabit Ethernet 1000Base-T reference Waveform (Test Mode 4)

Hi *,

maybe somebody can help me with some Gigabit Ethernet question ...

I do have a system that does just fail Ethernet Transmitter distortion
compliance test (Spec limit +/-10mV).
Other similar systems do pass the test. I have captured the
corresponding Traces and compared both systems.

Just from the Trace there is nearly no difference.

Then I do have a third system that passes with quite some margin.
Looking to the compliance trace of this one it looks not really good as
it has much lower slew rate.
But also the drivestrength seems to be less, so it seems that the drive
strength of the failing system is too strong.

Checking the 802.3 IEEE spec there is basically the Matalab code for
generating the reference trace and calculating the slew rate included
(in 40.6.1.2.4 Transmitter distortion).
But I have to admit that my Matlab is a but rusty and I do not really
speak this one fluently (so maybe I'm also wrong in this assumption).
I would like to compare the traces with the ideal Waveform to get a
better feeling what's wrong there.
==> So I would hope, that somebody would have this reference Trace
already available as Voltage/Time ASCII file.

Thanks in advance if anybody can give me some hints here, or provide the
Reference trace...

Best regards

Hermann
 

-- 
Our next Events:
================

Visit us on Embedded World 2012 
Our location Hall 1 / Booth 509

"Hunting PCIe Jitter"
Seminar on 26th January and 7th February

Check our website or contact us for details

EKH - EyeKnowHow
Hermann Ruckerbauer
www.EyeKnowHow.de
Hermann.Ruckerbauer@xxxxxxxxxxxxx
Veilchenstrasse 1
94554 Moos
Tel.:   +49 (0)9938 / 902 083
Mobile: +49 (0)176  / 787 787 77
Fax:    +49 (0)3212 / 121 9008

------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List technical documents are available at:
                http://www.si-list.net

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu

Other related posts:

  • » [SI-LIST] Gigabit Ethernet 1000Base-T reference Waveform (Test Mode 4) - Hermann Ruckerbauer