When viewing eye patterns you either have to have the scope trigger on = a clock signal that has a frequency of the max data transfer rate. If = you are looking at 100 MB/sec then you need a stable synchronous clock = of 100 MHz. You cannot trigger on the signal you are trying to = observe. You then can set the display on the scope to be in = persistence or whatever to get the best display. Any scope will do eye = patterns, some just add more processing and display features. Tom Dagostino Modeling Manager Mentor Graphics Corp. SAE tom_dagostino@xxxxxxxxxx 503-685-1613 -----Original Message----- From: John@xxxxxxxxxxxx [mailto:John@xxxxxxxxxxxx] Sent: Tuesday, November 13, 2001 12:50 AM To: slai Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Are there any ways to use DSO type scopes for = eye p attern measure ment? Hi Samuel, Thank you for your helps. The signal I measured is a differential type signal, swing from +1 V = to -1V volt. I triggered the signal with edge type . The scope can catch the signal well without moving and therefore, no = eye pattern shown.=20 Would you please provide more detail instructions to show the ways of = doing? I appreciate you for helps. >8-) John Lin=20 Senior SI Engineer, Server Team, ARD4=20 Quanta Computer Inc.,Taiwan, R.O.C.=20 Email: John@xxxxxxxxxxxx=20 Tel: 886+3+3272345 ext. 5183=20 -----Original Message----- From: slai [mailto:slai@xxxxxxxxxx] Sent: Tuesday, November 13, 2001 10:36 AM To: John Lin (=AAL=B4=C2=B7=D7) Subject: RE: [SI-LIST] Are there any ways to use DSO type scopes for = eye p attern measure ment? John, This is Samuel Lai from Micron Taiwan. The below is the advice from = Micron Boise lab. FYI. DPO is a Tektronix gimmick that not many people use. We do data and = address eyes all the time with our Agilent Infinium scopes. It can also be = done pretty easy on Tek scopes. Trigger on a setup violation for instance. = Or you can just trigger on a clock and capture all transitions. If you = are looking for a specific command, you might need to qualify with a state. Then put the display of the signals to infinite persistence or even = variable persistence. The 694 colors all channels to one color, I believe, = which makes it hard to read. The newer scopes put all signals to their own = colors like the Agilent ones. Then you can use the cursors to measure the = worst case setup and holds for both high going and low going patterns. Also, Infinium has a lot of features like masking that will allow you = to measure an eye, and then turn it into a mask. Then any violations to = the mask are recorded or stopped on. Let me know if I should send some waveforms or anything. DPO is just = DSO with infinite persistence on. -jon ------------------------------------------------------------------ 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 archives are viewable at: =20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages=20 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 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