Hi Joe: ---------------------------------------------------------- Delay Rise(ns) Delay Fall(ns) Overshoot(V) Osc(V) ERROR min max min max Low High MAX ============================================================================ = SDRAM Input 31.11 31.91 31.21 31.97 -0.00 -0.00 0.00 D ----------------------------------------------------------------------- XTK is reporting a (D)elay error on your SDRAM_clk net, but it appears that you may not have everything set up properly. "Buff Outp VM (lh) 0.00 VM (hl) 0.00" XTK should be getting "VM" (from XTK's .MOD IC model) from Vmeas in an associated IBIS model, if available. It looks like the model creator, however, didn't include "VM" in the driver model. To make the associated delay calculations, XTK would need to subtract the time that the Input voltage crosses Vinl and Vinh to determine min and max delays. If data is lacking for the driver, I would look to verify that Vinl and Vinh values are included in the input model, as well. If the data are there (for the input), you can take their average, plugging this in for Vmeas, lacking better data from the IC vendor. If Vmeas (VM), Vinl, and Vinh were all OK (they don't appear to be), XTK is telling you that -- on the rising edge -- the Input voltage crossed Vil (Min Delay) at 31.11 ns from the time the Output voltage crossed Vmeas (the earliest that the receiver could see a "1"). Similarly, the Input voltage crossed Vih (Max Delay) at 31.91 ns from the time the Output voltage crossed Vmeas (the latest we would expect the receiver to see a "1"). Similar reasoning would follow for the falling edge. These results are compared to thresholds that you provide XTK with, and -- if you fall outside the thresholds -- you end up with flags in the ERROR column. If you have no idea what Vinl and Vinh are, you can use .75 x the rail voltage for Vinh, and .25 x the rail voltage for Vinl, and .50 x for Vmeas, but these would just be qualitative guesses. The manufacturer should provide this data. Best Regards, Bill Hargin Direct: 425-702-0744 Fax: 425-702-0305 Cognition Consulting Electronic Design Software and Consulting http://www.CognitionConsulting.com > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx > [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Joe Young > Sent: Tuesday, March 26, 2002 1:13 PM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Interpretation of XTK results > > > > Hi experts, > I am a new guy for XTK. I don't know whether i am > interpreting the XTK results properly. I have copied results in > this email. Could anybody please explain me the results? > ---------------------------------------------------------- > Delay Rise(ns) Delay Fall(ns) Overshoot(V) > Osc(V) ERROR > min max min max Low High MAX > ================================================================== > =========== > SDRAM_clk > Buff Outp VM (lh) 0.00 VM (hl) 0.00 Vgb 0.00 0.00 > Vcb 0.00 0.00 > SDRAM Input 31.11 31.91 31.21 31.97 -0.00 -0.00 > 0.00 D > SDRAM_clk 31.11 31.91 31.21 31.97 -0.00 -0.00 > 0.00 D > ----------------------------------------------------------------------- > ---------------------------------------------------------------------- > > rgds, > Joe > > > 2,000,000,000 Web Pages--you only need 1. Save time with My Lycos. > http://my.lycos.com > ------------------------------------------------------------------ > 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 > > ------------------------------------------------------------------ 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