Silly resistor values

PSpice Schematics has a checkbox to choose netlisting method, flat or hierarchical. Crapture probably does also. Charlie???

...Jim Thompson

No, top of the line name-brand 'puters. When more demanding apps such as SPICE, SolidWorks or AutoCad don't crash that is kind of a sign that there's a wee problem with the SW I'd think.

Oh, and Cadsoft Eagle? Hasn't crashed in years, since the first day I fired it up. That's what I expect from CAD and that's how it ought to be, as far as I am concerned. And being self-employed I vote with my wallet on this stuff :-)

Reading you occasional comments about PSpice schematics it sounds like it must be the best thing since pivot irrigation. Why don't they sell it stand-alone, sans SPICE? There is a serious market out there.

Typically it numbers right on through if you hit auto-number. But it really never mattered to me in my Orcad days because most clients wanted a back annotation anyhow, so that the top left of the physical PCB started with R1, C1 and the bottom right would end with R542, C367. Then that got fed into the schematic, I updated my module spec with the new refdeses, done.

Most CAD programs have pretty powerful scripting languages. So you could, for example, exclude R666 or any refdes with a 13 in there if it made you uncomfortable :-)

And you folks bitch about top posting when we've got to paw through four pages of 8-deep quoted lines to get to a (mostly useless) one line response? Can we say "snip"?

Jim

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Hi Jim, Sorry, been distracted by local politics (interesting story...Charlie for Mayor? ;-) )

Ok, in Capture, go to the project view (the design heirarchy) and select the DSN file. Go to Tools/Create Netlist and choose the PSpice tab. There, you will find the checkbox for Heirarchical Netlist.

Any other questions?

Charlie

I believe it's a freebie off the web somewhere(*). It doesn't require a license. OrCAD only includes it on demand... like me, I refuse updates unless Schematics is included.

(*) Look for student or evaluation versions... v8 is best, before OrCAD hobbling ;-)

...Jim Thompson

Ok, another one for me. History Lesson...

Back a ways, Microsim and Orcad mergered. This created a problem. Orcad had Capture, a schematic capture program with the largest market share in the market, and Microsim had Schematics, a schematic capture program that had been streamlined for simulaton based design. In terms of operability, however, Capture had major stability problems, while Microsim had just sent out Release 8, a version of the software that was noted for its stability and usability.

From a business standpoint, this was a no brainer - go to Capture. There were just two problems - Capture was notoriously unstable, especially since they would just 'add-on' new program interfaces, rather than modify the underlying code, and the fact that Schematics had a loyal, even fanatical user base.

The first version of the merged software was V9.1. Everyone admitted that the Capture-PSpice interfaced was FUBAR in that version, but TPTB refused to allow a version of Schematics to be released. Result - huge drop in sales. I was working on the installation team, and even there, the differences in corporate and R&D philosophies was markedly evident.

They immediately came out with V9.2. This version was usable, and had most of the major functionality analog designers needed. They also came out with a translator for Schematics to Capture that worked very well. Finally, they made available a version of Schematics that also worked with PSpice 9.2. Result, greatly increased sales, especially since, to get Schematics 9.2 you had to first purchase Capture 9.2!

Another side effect was, since the translator worked so well, serious designers (such as Jim) continued to use Schematics, and when necessary, just translated them to Capture. Even in support, we typically created parts and libraries in Schematics (which had much better utilities for such things) and then translated them to Capture.

After this, Cadence bought Orcad, and everything went downhill ;-)

Charlie

I can believe it. I'm the neighborhood pain-in-the-ass, writing guest editorials, etc. Gets me calls from the mayor's assistant, who, in typical Democrat style, tried to shout me down... doesn't work very well with someone who can out-shout and out-cuss a sailor ;-)

I ran for school board in the early '70's, finished 6th in a field of

I play games with flat and hierarchical depending on what is wanted by layout, and in those cases that go weird... as you know. Even Mohi didn't know how to fix that ;-)

I'm also stir crazy with Templates, currently using 'Template" (standard), 'LVS' and 'HSpice', so I can pass on netlists to just about any simulator or layout tool. Aaron also wrote a 'cruncher' executable that calculates and clears all {..} for simulators that can't cope with '..' or {..}

...Jim Thompson

understand

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I don't understand that. If the schematic has a main controller part and, say, 16 channels, and you draw one instance of the channel, abstract that into a block, and draw 16 of the blocks - which is what a hierarchical schematic does - how does each instance have its own reference designators, sequantial across all the modules?

How do you print the schematic for field service? Where the hell is R325 in one of the instances when only one sub-module schematic exists?

John

Yes, it just starts with the next available number at block 1, then goes on to block 2 and so on until all sub-sheets are done. For proper documentation you must let it print out all 16 blocks, otherwise a technician could never repair the unit. For a design review you don't necessarily have to (in med or aero and such you usually do).

There are tons of other options for numbering but since many of my larger designs get renumbered anyhow I don't care that much. As long as the CAD doesn't screw up multi-device chips like gEDA does.

Field service needs all 16 sub-module pages. It has to be that way on any design because R325 will be R291 on the previous channel. Unless the sub-modules are separate little boards stuck into a big one but then they'd be another assy number.

In PSpice you can have schematic "instances". I don't use it because I do chips, so each repeated hierarchical block can reference the same schematic. But a PCB-based designer would use either "instances" or simply repeat pages (copy), which would generate individual reference designators.

...Jim Thompson

Particularly when it only crashes when doing one or two functions.

Nothing else on my work computer crashes regularly, except Capture.

...but you can't expect DimBulb to make any sense.

That sets up the netlist, but how do I use that information within Capture itself? My issue is (or was, I already did it the hard way) creating differential pairs out of signals down in the hierarchy. It has to be done from the flat nets dialogs and there is no hierarchy information there.

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Capture renumbers - flat - them for each instance.

They all exist. You print all the sheets. Ugly as hell, but it's really not much worse than flat schematics. Much better if you use a viewer.

We're planning on setting the service and test departments up with schematic viewers so they can use the hierarchy.

We tend to start numbering from xx01 on each sheet, with duplicate sheets having the same low order numbers.

I can add one that crashes more, on all computers here: Adobe Acrobat Reader. But I guess everyone knows that.

Yep, you's guys can get away with just placing the blocks. That's also how the chip designs went where I was involved. This is because it rarely happens that a technician has to swap a FET inside a chip ;-)

Hey, did you start modernizing the place? When I did that the first time it was met with quite a bit of resistance. Until they started feeling the benefits. "How did you get that stock room quantity?" ... "From my computation machine." ... "Oh."