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Annotate symbol with design variables

Hello,

I would like to add a label (by means of ILLabel guess) to the symbol whose value depends on global design variables. Let's imagine we had a symbol for a transmissionline segment consisting of a cap with value Par("C") and an inductor with value pPar("L"). When instantiating the cell we would set C=DESIGNVARIABLE_C and L=DESIGNVARIABLE_L. In the label I would like to see the result of ZW=sqrt(L/C), but values of the design variables (DESIGNVARIABLE_C and DESIGNVARIABLE_L) should be taken into accout. Is there any easy way to evaluate the expression sqrt(l/C) in SKILL? I have had a look at ael* functions to interpret expressions, but the parser seems to be unable to find out design variable values. I am using IC 5.1.41 with analog design environment for the global variables.

Thank you so much for your help,

Phil

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ritterp over 14 years ago

... well one tiny problem remains. The method you proposed works well if the parameters of the cell are given directly (e.g. L=1pH,C=1fF) in the very same level in hierarchy- in this case iPar("L") returns the right value. In contrast, iPar("L") does not seem to be evaluated if L of the cell is defined as pPar("L")
To sum up: this one works:
bottom layer: L=1nH
                     C=1fF
                    ZW=sqrt(iPar("L")/iPar("C"))
top layer: not applicable
whereas this one does not:
bottom layer: L=pPar("L")
                      C=pPar("C")
                     ZW=sqrt(iPar("L")/iPar("C"))
top layer: L=1pH
                 C=1fF

Am I right if I assume that this is due to using the same identifier for the actual parameter and the name for the inherited one? Is there any solution to this (I would like to avoid to name them differently in each level of hierarchy a parameter is passed through)?
Best regards,
Philipp
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ritterp over 14 years ago

... well one tiny problem remains. The method you proposed works well if the parameters of the cell are given directly (e.g. L=1pH,C=1fF) in the very same level in hierarchy- in this case iPar("L") returns the right value. In contrast, iPar("L") does not seem to be evaluated if L of the cell is defined as pPar("L")
To sum up: this one works:
bottom layer: L=1nH
                     C=1fF
                    ZW=sqrt(iPar("L")/iPar("C"))
top layer: not applicable
whereas this one does not:
bottom layer: L=pPar("L")
                      C=pPar("C")
                     ZW=sqrt(iPar("L")/iPar("C"))
top layer: L=1pH
                 C=1fF

Am I right if I assume that this is due to using the same identifier for the actual parameter and the name for the inherited one? Is there any solution to this (I would like to avoid to name them differently in each level of hierarchy a parameter is passed through)?
Best regards,
Philipp
Cancel
Vote Up 0 Vote Down

Cancel

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