Check LVS for Pcell

Hi Andrew,

I have a new problem. I have been written a code to create a pcell resistor by skill language. The properties of the pcell resistor in schematic and layout are the same. But when I run the LVS check, the mismatch is happened. A reason is that I have changed a function ( the function to calculate resistor value). I changed it in the cdf parameter file, the spice library (to run simulation). I do not know that I must change an other  file to pass the LVS check. Have you any ideal for this problem ? 

I known this issue is not your major. But If you have any ideal, help me please.

Thank you 

I know physical verification tools too - I just can't help you with Calibre, because it's not our tool and I don't have access to it.

I am assuming this might require you to change in one or two places. Either you need to alter how the CDL netlist is produced (this is in the auCdl simulation information section of the CDF) or change the calculations of the parameters being compared in the LVS rules, or possibly both.

It probably depends on whether the LVS is extracting and comparing the physical parameters (width, length etc) or the electrical parameters (resistance).

Really can't help much more given the lack of visibility as to what the actual problem is!

Regards,

Andrew.

Thank you so much, Andew

I am looking for information about this issue. Your instruction is verry helpful

Hi andrew, I have designed a simple opamp. Then I checked LVS and DRC. They are cleaned. But when I run "abstract" layout of the opamp circuit. Errors are happened. Like that: undefined function - pcDefinePCell
*Error* load: error while loading file - "code_pcell/pcell_SoiMOS/mp_soi.il"
*Error* eval: undefined function - pcDefinePCell

And the via I created by Cadence Tool have an error: *Error* eval: undefined funciton - leDefineMPPTemplate... But these functions (pcDefinePCell, leDefineMPPTemplate) have already had in cadence tools. So, I do not know how to fix this problem. Could you help me solve this issues ?. Thanks

I don't know where you are seeing these errors - without knowing that it's hard to know.

However, it sounds as if you're loading the code containing pcDefinePCell in (say) the libInit.il of the library; that makes no sense, as you wouldn't redefine the PCell every time the library is opened - once you define it, the code is stored within the view and there's no need to keep redefining it (and you'll hit issues like this).

Maybe you're also calling leDefineMPPTemplate() too in the libInit.il - that is not available in all interfaces (like the stream interfaces) - you could instead add:

when(isCallable('leDefineMPPTemplate)
  leDefineMPPTemplate(...) ; or load the code containing this call
)

As I said, without knowing what files you have, what's defined where, and what is producing these errors, I can't really be more specific - this is all based on supposition and guesswork.

Regards,

Andrew

HI Andrew,

The program that I used to abtract show on the figure. Exactly, you said, I have load my pCell code from the lib.init file and have some warning like that "redefine". These warnings was cleand, when I just load my code once time. But the errors such as "undefine function - pcDefinePCell" are happened. Have you any solution for this problem?.

Thankyou,  

Yes, I have a solution. As I said before, don't call pcDefinePCell from the libInit.il - this is not necessary (and in fact is bad practice, as usually users wouldn't have the permissions to redefine the PCells each time - all you need to have loaded are any auxiliary functions called from within the pcDefinePCell code block).

Regards,

Andrew.