I think that the outside world and managers are under the belief that the eyes of the world all look like the attached. Nice explanation, and attachment I couldn't find a pic fast enough to match the description. I always love hearing, can't you just tweak a knob or something to fix that? -Mike. On Wed, Sep 23, 2009 at 3:40 PM, Richard Feldman < Richard.Feldman@xxxxxxxxxxx> wrote: > The unsymmetry just means the first half of a driven step (0 to 50%; right > side of eye) > slews faster than the second half (50% to 100%; left side of eye). Very > common with simple plants; a plain RC lowpass step response will have that > characteristic. Here is the first image example I found by googling: > > http://www.altera.com/products/devices/arria-fpgas/arria-ii-gx/images/eye-diagram.jpg > > Rich > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] > On Behalf Of Morse, Jeff > Sent: Wednesday, September 23, 2009 12:14 PM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Eye Diagram Question > > Hi, > > What would cause an eye digaram to be asymmetric between the left and > right hand sides? I am looking at an eye that has a left hand side that > has a very shallow rise/fall to the respective zero and one levels. The > right hand side has much sharper rise/fall. I understand there are > frequency dependent losses, but I would *think* that would affect both > sides of the eye in the same way. I played with preemphasis in the > driver - but didn't see much effect. > > Any ideas what this might be / not be? ISI, reflection, etc? > > Thanks, > Jeff > > This message is intended only for the designated recipient(s) and may > contain confidential or proprietary information of Mercury Computer > Systems, Inc. This message is solely intended to facilitate business > discussions and does not constitute an express or implied offer to sell > or purchase any products, services, or support. Any commitments must be > made in writing and signed by duly authorized representatives of each > party. > > > > > ------------------------------------------------------------------ > 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 technical documents are available at: > http://www.si-list.net > > 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 > > > ------------------------------------------------------------------ > 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 technical documents are available at: > http://www.si-list.net > > 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 > > > -- Best Regards, Michael C. Greim And all this science they don't understand Is just my job six days a week..... We will either find a way or make one -Hannibal In the middle of every difficulty lies opportunity -Al Einstein ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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