Hi everyone, I have a Senior SI engineer opening in my group. Please send all resumes to Mohammadt@xxxxxxxxxxxx Thanks, Mohammad -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Loyer, Jeff Sent: Monday, May 22, 2006 1:29 PM To: Aubrey_Sparkman@xxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Ring back I don't think you'll find a definitive answer. =3D20 In Intel FSB specs, we talk about "positive ringback" (on rising edge) and "negative ringback" (falling edge), but then we use the terms "overshoot" and "undershoot" to describe similar phenomena with different polarities. (see http://www.intel.com/design/pentiumii/datashts/24365703.pdf, page 40). I don't know how other vendors use the terms. I first hit this several years ago doing slot 2 designs and it's always been counter-intuitive to me - I would prefer the terms "positive overshoot" and "negative overshoot" instead of "overshoot" and "undershoot". But, there was too much momentum behind the existing terminology to change it. So, I've adapted my terminology accordingly. To me, the bottom line is that these terms, like many in our discipline, are merely conventions, and ambiguous ones at that. It's best to very carefully spell out exactly what we mean when using these terms (which this spec does). Likewise, even "stripline" is used to describe several similar topologies - if there's an "absolutely correct" definition, it's probably lost to history, and won't help you when someone else misunderstands what you meant (regardless of whether you were correct or not).=3D20 Obligatory Disclaimer: The content of this message is my personal opinion only and although I am an employee of Intel, the statements I make here in no way represent Intel's position on the issue, nor am I authorized to speak on behalf of Intel on this matter. Jeff Loyer -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Aubrey_Sparkman@xxxxxxxx Sent: Monday, May 22, 2006 11:40 AM To: art_porter@xxxxxxxxxxx; leeritchey@xxxxxxxxxxxxx; madhusudhan@xxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Ring back Doesn't the concepts of over-damped (undershoot), under-damped (ringback), and critically damped systems apply here? Aubrey Sparkman=3D3D20 Enterprise Engineering Signal Integrity Team Dell, Inc.=3D3D20 Aubrey_Sparkman@xxxxxxxx=3D3D20 (512) 723-3592 The Greatest Pleasure in Life is Doing what People say can't be done... -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of art_porter@xxxxxxxxxxx Sent: Monday, May 22, 2006 11:23 AM To: leeritchey@xxxxxxxxxxxxx; madhusudhan@xxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Ring back I would argue that there is a difference. Undershoot is defined by the = =3D =3D3D =3D3D3D IEEE in standard 181-2003 as "3.1.49 undershoot: A waveform aberration =3D3D =3D3D3D within a post-transition aberration region or pre-transition aberration =3D3D3D region that is less than the lower = state boundary for the associated =3D3D =3D3D3D state level." In layman's = terms, undershoot does not require a preceding =3D3D3D overshoot. Ringback to = me, again in simple laymans' terminology, is the =3D3D3D first (or lowest) = dip AFTER an initial overshoot. "Ringback" to =3D3D me =3D3D3D implies that = =3D there is some resonance, so one would expect to see a =3D3D =3D3D3D damped = sinusoid following a transition. There is no IEEE standard definition for "Ringback," but I believe it = =3D =3D3D =3D3D3D has been defined in some semiconductor manufacturers' data = sheets and =3D3D =3D3D3D app notes. =3D3D3D20 Art Porter Agilent Technologies =3D3D3D20 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] =3D3D3D On Behalf Of Lee Ritchey Sent: Monday, May 22, 2006 9:02 AM To: Madhusudhan Kulkarni; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Ring back Ringback is just another name for undershoot. I don't know why someone =3D3D3D had to invent another name for something that already had a = name. When you have undershoot and you use series terminations, the terminator value it too high or the output impedance of the driver is too high. = =3D =3D3D =3D3D3D When you have undershoot and you use parallel terminations, the value of the terminator is too low. Fix which ever problem you have by changing the value appropriately. > [Original Message] > From: Madhusudhan Kulkarni <madhusudhan@xxxxxxxxxx> > To: <si-list@xxxxxxxxxxxxx> > Date: 5/22/2006 9:28:26 AM > Subject: [SI-LIST] Ring back > > Hi, > How to solve ringback problem and what is the disadvantages of =3D3D3D ringback > ------------------------------------------------------------------ > 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 FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: =3D3D3D20 > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > =3D3D3D20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =3D3D3D20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =3D3D3D20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =3D3D20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =3D3D20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =3D20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =3D20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu