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Include file in spectre (Read 4543 times)
sdv30
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Include file in spectre
May 27th, 2016, 12:04am
 
I have a very simple question.
I am trying to include a file in spectre. I have the simplest setup possible.
I am using an empty netlist (only entry is simulator lang=spectre) and using a stimulus file, where I have only one include statement:
include "RefClk.txt"
The RefClk.txt file has a pwl voltage source in spectre syntax (simulator lang=spectre at the top of the file).
The issue is this: When I have a very low number of time/voltage pairs (e.g. 50) then the file is included and the simulation completes correctly.
When I try to include a more realistic pwl waveform with ~1000 time/voltage pairs, the simulations hangs.
Has anyone seen anything like that?
Thanks.
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sdv30
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Re: Include file in spectre
Reply #1 - May 27th, 2016, 12:38am
 
Here are the ocean file used for the simulation and the log file:
-------------------
simulator('spectre)

; PARAMETERS OF THE SIMULATION:
tEnd= 1e-05
desVar("tEnd" tEnd)

;********************************************
; DESIGN SETUP:
design("./netlist")
stimulusFile("./stimulus" ?xlate nil)
temp(25)
analysis('tran ?stop "tEnd" ?errpreset "moderate")
;analysis('tran ?stop "tEnd" ?errpreset "conservative")
option( 'gmin 1e-14 'vabstol 1e-16 'reltol 1e-10 'iabstol 1e-16 )
resultsDir("./")
run()
results()
selectResults('tran)
outputs()

; REFERENCE CLOCK ZERO CROSSINGS:
ZCref=cross(v("Vref") 0.5 0 'rising)

out= outfile("ZCref.mat");
fprintf(out "%% Zero Crossings \n")
ocnPrint(?output out ?precision 20 ?numberNotation 'engineering ZCref )
close(out)

----------------------------------

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Loading socket.cxt
Loading dal.cxt
Loading awv.cxt
Loading par.cxt
Loading alvs.cxt
Loading caa.cxt
Loading adexl.cxt
Loading te.cxt
Loading schHDL.cxt
         Type ocnHelp() for help on OCEAN commands.
         Look in .../tools/dfII/samples/artist/OCEAN for example
         OCEAN scripts.
nil
ocean> *WARNING* (icLic-3) Could not get license Analog_Design_Environment_L
ocean> ocean> ocean> *INFO* (icLic-25) License Analog_Design_Environment_XL ("95210") was used to run ADE L.
Loading devCheck.cxt
Loading relXpert.cxt
spectre
1e-05
ocean> "1e-05"
ocean> ocean> ocean> ocean> INFO (OCN-6058): amap directory is missing in the netlist directory. Schematic names will not
       get mapped to simulator names. Ensure that amap directory is present in the netlist
       directory.
"./netlist"
ocean> ("./stimulus")
ocean> "25"
ocean> "moderate"
ocean> ocean> "1e-16"
ocean> "./"
ocean>
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Geoffrey_Coram
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Re: Include file in spectre
Reply #2 - May 27th, 2016, 6:48am
 
It sounds like you have a pwl source with a vector of t,v pairs like [0 v0 t1 v1 t2 v2 ...], and that vector is very long.  Doesn't Spectre also allow you to specify a file for the t,v pairs?  So the file would only have the t,v data (and the pwl source instance would be in a different file, such as the original netlist).  I think the simulator may be better optimized for that case.
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sdv30
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Re: Include file in spectre
Reply #3 - May 27th, 2016, 9:52am
 
Thank you for the reply. It turns out the simulation settings were too strict. If I relax them, I can get it to work.
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Ken Kundert
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Re: Include file in spectre
Reply #4 - May 28th, 2016, 11:17am
 
Always start with the default tolerances!

Also, it was a weird choice showing us the Ocean files. The problem was with the simulator. You should have shown us the simulation files.

-Ken
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AMS_ei
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Re: Include file in spectre
Reply #5 - Jul 13th, 2016, 6:20am
 
Hi,

There is a parameter in spectre: reltol.
You may please change its value to 0.001.

Hope this may help you.

Thank you.
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