Analog Environment -> Changes Don't Produce new sim results

Hi all, when I use Cadence, I will run a simulation, make a change to my
schematic, or simulation, and then do a new 'netlist and simulate'. Well, I
nearly went crazy the other day trying to find out why my changes weren't
producing the changes I thought they should.

Cadence will go through the motions, perform a simulation, and the results
will not change. You can close down the Analog Environment, restart it, and
run the simulation successfully. This is not the way things should be
though. Even adding another simulation such as AC will not produce any AC
results if you started out running DC or transient.

So, any ideas on what is causing this problem? Again, if I change the
schematic and try re-running the simulation, it seems to be running the old
one over again. I am checking and saving my schematic, and I am creating a
new netlist...!

Thanks,

Marc

 

It's Cadence... what else can you say ?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

Heh heh, yeah, I'm starting to understand the sentiment. However, I'm stuck
with it... The tools hurt you as often as they help you.

Curse you Cadence!!!

Marc

 

Does the netlist change when you change the schematic or not ?
What if you use "Recreate Netlist" instead of "Netlist and run" ?

If your data is stored on a remote machine, the problem could be
related to different system clocks between the two machines.

Stéphane

 

Do you check and save your toplevel schematic before starting
simulation?
Are you changing any referenced libraries?
Check the input.scs file in the netlist directory in your Project
directory to see if its date change.
Do you have any saved simulation data that accidentally get viewed
instead of your new ones?
Are you creating the netlist or are you recreating the netlist?

 

Yes, I checked and saved. Like I said, it appears to netlist and run
through simulation. I did look at the input.scs file and the netlist was
changed. For example, a line was in there to run the AC sim, but nothing
happened.

Other members of our group had the problem but didn't fix it.

I'll look into the system clock idea mentioned earlier.

 

Yes, I've tried the recreate netlist, plus I've looked at it. The new code
reflecting the changes is there. I'll investigate the system clock thing.

Thanks!

Marc

 

What version are you using? I've not seen this problem for some considerable
time...

Andrew (trying to be constructive rather than just Cadence-bashing).

 

obviously the clock trick won't work.
it could prevent the re-netlisting, if a clock difference
makes it think the netlist isn't older than the latest schematic.
if the netlist is correct, then it's not the problem.

so sad, i remember having had this problem but cannot remember
if and how i was able to deal with.

I'll post if it comes back,

stéphane

 

I'm guessing from context you're running in "Analog Environment"
(artist) and not generic Tools->Simulation mode.

I've only ever seen the behavior you describe when doing
"out-of-band" netlist modifications; SKILL that did netlist
post-processing outside the artist environment. In that case,
the *still-running* spectre process was simply re-running
without restarting or re-reading.

Workaround was just to Simulation->Stop before
Simulation->Run. I'd be moderately surprised
if that doesn't work for you while you're pursuing
a real solution.

-Jay-

 

See old post entitled "spectre interactive mode". I have seen the
problem you describe and used spectre.envOpts controlMode 'string
"batch" to get around it.

See sourcelink solution #1838156 and #1834453.

I did file a SR on the topic (SR 32341432) and PCR 564650 was opened.
I however got tired of trying to get Cadence to reproduce on their end
as it takes some time before updates stop getting simulated and I
didn't have a procedure to recreate the problem every time. If you
have the time please file a SR and get Cadence to reproduce so that
the spectre interactive mode gets fixed.
---
Erik

 

I believe it's 5.0.32...off the top of my head.

Marc

 

HI,
I had that problem once while using spectre for analog cmos
designs.Since we didnot have a startupfile ,I was having same problem
as yours.
what I did to overcome the problem was,I did "check and save" the
design after I modified it.Then from simulation dropdown list ,select
"netlist and run".This will most probably solve your problems.
If u have to use a "source startup.txt " make sure u use it before
running simulations.
Regards
harry

 

Hi Harry, I do that routinely, but the changes still don't stick. I've read
it could have something to do with the license file for reasons that beat
me.

I don't know what the startup.txt file is. I do have a .cdsenv file...

Marc