Re: Pspice compatibility: Bus representation in subcircuit calls

On 01 Dec 2003 21:30:58 GMT, "Mike Engelhardt" <[EMAIL PROTECTED]>
wrote:


>I realize that I throughly pissed Larry off. 

Not at all.  I have actually been enjoying this, hoping to learn
something. So far I've learned you seem to think you're God. . .

>"God can't help you if you're stupid." Mike E

 What
>it is.  But, I don't think Larry has justification
>to get excited after he makes false claims about
>LTspice from wrong conclusions about what
>schematic capture is used in house.  

Not this again.  Who's making false claims?

The Snynario
>netlister does not meet your list requirements and
>we don't use it. 

Linear Technology may not use it, but there's nothing wrong with the
netlisters in Cohesion.  They've performed flawlessly for over 10
years in the various forms.  The designers said once the database is
actually organized in the same way a spice netlist is.  The result is
I can netlist a design instantly in Cohesion that would take several
minutes in Edge.

The software will output both hierarchical and flat netlists.  The
hierarchical netlister as options to output Berkeley Spice, Pspice,
Hspice, LVS, and CDL.  It also has a pretty cool option that does
essentially what Jim's work-around does for pulling in supplied
subcircuits.  Make a dummy cell with the same name as the subcircuit
and put the subcircuit netlist in the local directory.  Every time you
netlist, it automatically pulls in the subcircuit.spi file.  

The flat netlister is similar.

The software also has provisions for vhdl, edif, and verilog. 

 I thought it was pretty stupid to
>draw conclusions about what LTspice can do from a
>netlister that is only used with LTspice by Larry
>to the best of my knowledge.  

I don't use LTspice for design and never will.  I wouldn't recommend
it for serious work to anyone else.  There are far too many negatives
which have nothing to do with someone elses netlister.

In general, I don't
>see an excuse for a netlister not to be able to
>make correct syntax netlists for different SPICE
>programs and LVS either; and I specifically don't
>see an excuse for drawing conclusions about
>different tools from using a netlister that isn't
>intended to work with them.
>

More vinegar from Mike about a program he's taken as the basis of his
schematic capture.  Imitation is, I hear, is the highest form of
flattery.  The problem isn't that he copied the wrong program.  The
problem is he's botched key features in it that are really useful.
He's also made his version incompatible with the original without
extensive editing - making it impossible to easily go back and forth
to his simulator with the exception of using a spice netlist.

After making the schematic capture unusable for many applications, he
picks on a program that is usable - the one he started with.  

Vision?  He's heard of it.

>Larry's used LTspice as his simulator for IC
>design and I've even helped him in the past with
>generating correct hspice syntax so that he could
>run TSMC(I think they were) libraries in LTspice.

I would never use LTspice in a design.  I did do an eval, then decided
it wouldn't do what I need it to do.  You (Mike) helped on occasion
with questions and I thank you.  On the other hand, the binning in
LTspice wasn't working properly and you fixed it.  Again I thank you.
I always give credit where credit is due. 

 You can also count on me for negative feedback when you start going
nonlinear. :-)

I did use LTspice once as one of 4 simulators for a data point in a
small design verification.  The actual design task was done on Mako
and smartspice.  Hspice was the other simulator used for this
verification.

ONCE AND FOR ALL: 

 I DON"T USE THE LTSPICE SIMULATOR FOR DESIGN!!  

NEVER DID!! NEVER WILL!!  

THE SCHEMATIC CAPTURE IS PURE CRAP!!

get it? 

>Now he wants to invoke the psychology of the
>customer being always right when he is not a
>customer in the remotest interpretation.  And
>he's difficult to work with because he doesn't even
>have hspice to try out the stuff I suggest so he
>can see what's really what in the intermediate
>syntax.

Maybe you have time for these simulation exercises, but I don't.  I
have all the access I need to hspice, but  I'm done looking at
LTspice. 

LTspice is ok for a first cut at small circuits, but that's about it
in my opinion. 

 I don't think it would save me time to capture an opamp in LTspice
for development, then recapture it in another tool, so I've deleted it
from most machines.

  While I don't much care what fabless IC
>design concerns do with LTspice, I do find it
>disingenuous to post stupid assumptions based on
>a lame netlister in response to someone answering
>his questions with a clear concise example that
>illustrates the thing he needs to know to solve
>his problem.

More vinegar.  

The online update in LTspice is actually a major drawback for any
design shop.  While great, it can make older schematics useless.
There's no guarantee and no archive that I found.  You'd have to
routinely back up the various versions of the program to be safe.  I
hate updating software in the middle of a design, anyway.  Imagine
using this with a design group and getting this sort of cooperation
from your employees.  I didn't see a way to deal with this.  Combined
with the poor documentation, the cost for using this program could be
high, indeed.

Regards,
Larry