[SI-LIST] Re: redriver issue

  • From: jun zhang <zhangjun5960@xxxxxxxxx>
  • To: dmarc-noreply@xxxxxxxxxxxxx
  • Date: Tue, 15 Dec 2015 10:14:56 +0800

For nonlinear redriver, is boost in redriver responsible for pre-channel
and tx-deemphasis in redriver responsibler for post-channel?
If lowest boost in redriver is higher the pre-channel insertion loss, does
it meaning over-equalization?

On Tue, Dec 15, 2015 at 4:28 AM, Hock Seow <dmarc-noreply@xxxxxxxxxxxxx>
wrote:

Hi All,
The new, well written Intel white paper (Rev 1.2, Oct 2015) compare
different repeats in market, would provide more useful information on this
topic. Go to Intel site and search for "repeater" and the white paper
should be the first one in the search result. Thanks!
Hock
From: Vinu Arumugham <dmarc-noreply@xxxxxxxxxxxxx>
To: si-list@xxxxxxxxxxxxx
Sent: Monday, December 14, 2015 10:23 AM
Subject: [SI-LIST] Re: redriver issue

A retimer "resets" the jitter. So every segment of the link can have the
full interconnect jitter budget.
However, the wander budget is NOT reset. Wander being defined as low
frequency jitter that is tracked by the CDR.
So wander introduced by the retimer needs to be accounted in the
end-to-end wander budget.
Industry standards may not always specify the details of wander
budgeting for retimer based links.
This increases the risk of interoperability failures.
Simple retimers are usually protocol agnostic. So things like link
training, receiver detection may not work.

Thanks,
Vinu



On 12/12/15 19:01, jun zhang wrote:
Dear all,
I focus on redriver now which amplifies the signal. I have tried both
linear and nonlinear redrivers in our projects and approach some strange
issues.

Besides above questions, I also have interest in the influence of return
loss, crosstalk, TX jitter, RX jitter to the performance of redriver and
the correlation between simulation and measurement.

Hope to your reply.

Regards


On Sat, Dec 12, 2015 at 11:15 PM, Walter Katz <wkatz@xxxxxxxxxx> wrote:

Chuck,

Correct. In the IBIS standard we use three terms, Repeater, Redriver and
Retimer.

A Repeater is either a Redriver or a Retimer. A Retimer recovers and
then
regenerates the signal. A Redriver amplifies the signal, and this
amplification can either be linear, or nonlinear.

Walter

-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx
]
On
Behalf Of Chuck Corley
Sent: Saturday, December 12, 2015 10:04 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: redriver issue

Hi Jun;

For your discussion there are several types of devices. There are
"redrivers" which primarily rebuffer signals for amplititude, and then
there
are also "retimers" which recover and regenerate the signals. The names
for
these functions can vary between manufacturers.

Chuck


Chuck Corley
National Instruments



On 2015-12-12 03:27, jun zhang wrote:
Hi all,
I think redriver is an old and still difficult topic.

we approach in simulation, redriver can amplify amplitude but reduce
timing margin case.

Also in test, we approach the case when adding in redriver, TX can't
find RX.

In redriver chip side, there are different kinds of redrivers:
limiting redriver and linear redriver.

It also seems the effects of redrivers are sensitive to positions it
locates, expecially for limiting redriver.

We may ship products that can work for PCIE Gen2 but fail for Gen3.
Because
of shipment already, we can't add redrivers in our products. So it is
an awkard situation when we want to run higher speed on our products.

So I hope you can share some successful experiecnes on this topic.
When we judge that the insertion loss of the link is high, the first
thought is adding redriver. But do we need to think more before adding
redrivers?
Are
we afraid that adding redriver will give even worse effects? What
kinds of redrivers are most suitable to our link?

Hope to your discussion on this interesting topic

--
best wishes,

Jun Zhang


------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list

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


List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:
//www.freelists.org/archives/si-list

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

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


List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:
//www.freelists.org/archives/si-list

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


------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list

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


List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:
//www.freelists.org/archives/si-list

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





------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list

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


List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:
//www.freelists.org/archives/si-list

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





------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list

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


List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:
//www.freelists.org/archives/si-list

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





--
best wishes,

Jun Zhang


------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list

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


List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:
//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: