Fatal error during callibre view in cadence

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im_pam

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Dear Cadence team,


i am using cadence virtuoso (IC6.1.7-64b.500.19), i have design a schematic in spectre and its layout. When symbol of schematic is used in new cell and copy its layout and rum pex, In callibre view . i got the following error

"*Error* Could not Evaluate property ad of value ((iPar("sb")) * iPar("w") / iPar("fingers")) + (iPar("sd") * iPar("w") / iPar("fingers") * 0) for the instance: I1_MNM7.
Calibre View generation encountered a fatal Error."

i am pissed off this error, please help me with the same
 

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Hi @im_pam
Most likely, you are using a parametrized cell and specifying values for W and L as a variable in ADEL, which is not directly translated to the netlist, hence LVS cannot do a proper comparison. Solution to that is to specify W,L and number of fingers and multipliers directly in transistor properties.
P.S. It would be useful to see your schematic, layout and properties of the instance I1_MNM7.
Hopefully, that helps.
 

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@sidun.av Thank you for the prompt response,
i have not define the w, l in terms of variables , they are specified as 200nm and 60nm still i am facing this issue
 

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im_pam said:
i have not define the w, l in terms of variables , they are specified as 200nm and 60nm still i am facing this issue
Click to expand...
Could you please show your schematic and properties of I1_MNM7 in schematic and layout?
It's very hard to guess without looking at your schematic/layout.
 

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@im_pam , I mean properties -> that's when you select your NM7 on schematic and then press Q you will get a pop-up window, displaying device properties. That's what I would like to see from both schematic and layout NM7.
Also, if you can send a netlist, that might be useful, too.
--- Updated ---

im_pam said:
When symbol of schematic is used in new cell and copy its layout and rum pex, In callibre view
Click to expand...
BTW, if you run PEX on this cell only (not it's copy) are you getting the same error? If no, it might be a problem with copying/specifying correct cell in PEX and I might need to see the Calibre PEX setup.
 

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It looks like the issue arises from Drain Diffusion calculations. Can you scroll down the parameters and check if there are any other options available?
Also, deleting NM7 and re-instantiating it again might help (this will eliminate the case where you occasionally modified some cell parameters that prevents PCELL from normal Drain Diffusion calculations.
 

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yes when i run on original cell , then no error occurs, but i am copying same way i do for other designs (here no such problem occurs). this issue occurs with this design only
 

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im_pam said:
yes when i run on original cell , then no error occurs, but i am copying same way i do for other designs (here no such problem occurs). this issue occurs with this design only
Click to expand...
In this case, you need to check 2 things - Calibre PEX setup and copy process.
Copy process:
- Are you copying your cells hierarchically? If yes, make sure that you do not skip any dependent library during copy;
- Open your schematic and check that all instances are linked to a correct library (if you don't do hier copy, it will be still linked to the old one);

Calibre PEX setup:
- Check all paths in PEX: for schematic netlist and layout database. Make sure that you are creating a separate database for you copied cell and don't take anything from the original cell.
- Check that names in PEX are correct;

Hopefully, that helps.
 

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Hey @sidun.av, problem is solved . actually i had changed the dimension of transistor but again modified it. i think my layout was taking somewhere modified data and cadence is not able to recognize . now i made the schematic and layout again from scratch and now it is error free.

anyways thank you for the help
 

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