Saoer, For jitter analysis, I guess you don't have to deal with non-transition signal for a given waveform unless there is amplitude-to-phase modulation. If you are able to dump your waveform from your tools, you might want to try this pseudo code in order to extract the transition part of your data. (If you are familiar with Python, it should be easier for you to go though the code) =3D=3D=3D=3D cross_zero(data, threshold): ### returns an array of crossing times. ### data is assumed to include [time, voltage] pairs in array ### threshold represents the crossing threshold crosses =3D [] # empty array t1,v1 =3D data[0] # the first entry of the data array v1 =3D v1-threshold for t2,v2 in data[1:]: # get the [time, voltage] pair out of # the array starting from the second entry v2 =3D v2- threshold; # We have found a falling edge=20 if (v1 > 0 and v2 <=3D0): ## collect interpolation data ## interpolation is done for time based on v1 and v2 crosses.append((t2*v1-t1*v2)/(v1-v2)) # We have found a rising edge=20 if (v1 < 0 and v2>=3D0): crosses.append((t2*v1-t1*v2)/(v1-v2)) t1 =3D t2; v1 =3D v2; return crosses =3D=3D=3D=3D Hope this helps, TK -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Saoer Sinaga Sent: Wednesday, May 21, 2008 4:42 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] transient and non-transient signals in Jitter analysis Dear all, In Jitter analysis, you need to separate transient signals and non-transient signals from serial signals. What do transient and non-transient signals actually mean here? Does the transient signal mean the signal that always changes (1010101....) ? and what about the non-transient signal ? How can I separate those two types of signals in simulation tools e.g. Cadence? thanks, Saoer ------------------------------------------------------------------ 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: =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 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