Hi SIexperts, I am doing Signal Integrity Analysis using Spectra Quest signal explorer. I have a problem in simulating MPC8260 model. First i converted MPC8260 IBIS model into ".dml" format using "ibis2signoise" utility and there was an error message " TV curve should start at zero". I changed the firtst line of the rising and falling waveforms data "zero" and now there was no error in the conversion and then i assigned this model to the device. When i tried to do the simulation using this I/O model it gives "SERIOUS Convergence Problem in Simulation of "DESIGN IO1 1" stimulus Pulse". Can anybody help me to solve this problem? Thanks and regards, Sivakumar.S -----Original Message----- From: Heiko Dudek [mailto:heikod@xxxxxxxxxxx] Sent: Thursday, August 09, 2001 3:31 PM To: we_r_frendz@xxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Simulation Question in Spectra Quest. Rahul, >1) The technology that I simulate makes use of >Differential strobes. Do I need to set up two strobes >in my simulation or a single strobe sampling at both >edges. If your strobe line is layed out as a differential pair, you definitely need to model this with a coupled trace element. Same for driver / receiver (take care, often differential drivers are used together with single receivers). You need to use single or differential models, depending on what you have in reality. No direct relation to sampling on rising, falling or both edges. This again depends on whatever technology you're simulating ... RAMBUS for example samples on both edges. This way, a 400MHz strobe results in 800MT/s. >2) Does the tool sample at both the edges or only at >the rising edges. whatever you want it to. Select 'Set'->'Strobe Pins'. In the 'Strobe Selection Window', you can set 'Active Edge' to 'Both', 'Rising' or 'Falling'. >3)When we make use of Custom measurements, In the IO >cell Edit window there is a column for Freq. Does this >frequency indicate the sampling frequency ( The rate >at which the data is being sampled ). If so what does >the Clock freq that appears in the Analysis >preferences window indicate. I assume you're talking about the I/O cell stimulus edit. You do have the choice between different stimulus states ... there's 'Rising', 'Falling', 'Pulse' and 'Custom' (and 'Quiet hi', 'Quiet lo' and 'Tristate' as well). Whereas all I/O cells with rising, falling or pulse waveforms are operating in sync and with whatever you set in the analysis preference window as clock frequency. If you decide an I/O cell to have a custom stimulus, you can set the clock frequency to whatever you want and individually for all custom I/Os. The frequency set in the analysis prefs has no influence on custom I/O stimulus. Hope this helps. - Heiko Heiko Dudek Technical Marketing Manager, High Speed Systems Design & IC Packaging Cadence Design Systems, 270 Billerica Road, Chelmsford, MA 01824 ph (office Chelmsford, USA): (978) 262-6384 ph (office Feldkirchen, Germany): (089) 4563-0 fx (office Chelmsford, USA): (978) 446-6798 fx (office Feldkirchen, Germany): (089) 4563-1800 mobile world phone: USA - (617) 230 4233 or Europe - (+49) (172) 938 1541 email: heikod@xxxxxxxxxxx ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field 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 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