Re: [SI-LIST] : Eye diagram displays from HSPICE simulations

D. C. Sessions (dc.sessions@vlsi.com)
Mon, 19 Jul 1999 13:59:14 -0700

Chris.H.Simon@gd-is.com wrote:
>
> Mike,
>
> You mention that you run many randomly switching bits in an HSPICE simulation
> and view the resulting eye diagram. Is there a way to view eye diagrams in
> Avanti Avanwaves or do you use some other waveform viewer with this capability?
> I have tried to do this in Avanwaves but couldn't find the right combination to
> get the overlayed waveforms.

Run the history with a sweep on the transient analysis statement, eg

.TRAN 10p 100n
+ SWEEP hist 0 255 1

where hist is the sequence clocked out before the transition in question
and you use a behavioral parallel-to-serial converter to initialize
everything. A randomizer can use the the parameter as a seed if you
don't want to use complete brute force. Alternately, you can drive the
sequence from a data file and just step through them.

Either way, the waveform viewer will pull up all of the generated waves
at once.

Do make sure you have LOTS of free disk before you try this, though.

-- 
D. C. Sessions
dc.sessions@vlsi.com

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