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Select schematic instance from instance iterations

Brouns Robin

 Hello,

I have a question, how do i select in SKILL a single instance from a
instance?

This is my situation:
I have a schematic with a instance I5<153:0> and this instance has 7
pins.
Connected to these pins are nets with "complex" net names.
Like
this :"<*4>(<*16>coladdr<4>,<*16>coladdr_<4>),<*16>coladdr<4>,<*10>coladdr_<4>".

I wanted to make a generic skill script that selects each iteration
(e.g. I5<15>) and generate a via matrix to forsee the correct connects
at his pins in layout.

However I have difficulties finding the right attribute to get the
list of the iterations.

This is how far i got:
libName = "my_lib"
cellName = "my_cell"

targetInstanceName= "my_instname<153:0>"

cvId=dbOpenCellViewByType(libName cellName "schematic" "schematic"
"r");

instList=cvId~>instances;

n=length(instList);
targetPosition=0;
for( index 0 n
        if(nth(index instList)~>name == targetInstanceName
        then
                targetPosition=index;
        )
)

targetInstance=nth(targetPosition instList);

From here i wanted to make an array from the iterations as objects and
then see what the connections should be for each pin.

Thanks for your help,

Robin
Parents

  • I answered this over on comp.cad.cadence - but for completeness, including reply here too:

    > Hi Robin,
    >
    > Could you explain what data structure do you want to have at the end ?
    > And I think that the code that you wrote above can be replaced with
    > targetInstance = dbGetInstByName(cvId targetInstanceName)
    >
    > At least it is (much) faster.
    >
    > BR,
    > Marcel

    I agree with Marcel - the way you're doing it is terribly inefficient. First of all you're treating the list you have as an array - it is NOT random access, and so you are having to do a sequential search from the beginning of the list each time you call nth(), and so that loop will be doing (roughly) N2/2 (where N is the number of instances). A foreach loop would be better, but best is the dbGetInstByName() function.

    Then you probably want:

    dbGetMemName(targetInstanceName 23) => "my_instname<130>"

    or

    dbProduceMemName(targetInstanceName)
    ("my_instname<153>" "my_instname<152>" "my_instname<151>" "my_instname<150>" "my_instname<149>"
        "my_instname<148>" "my_instname<147>" "my_instname<146>" "my_instname<145>" "my_instname<144>"
        "my_instname<143>" "my_instname<142>" "my_instname<141>" "my_instname<140>" "my_instname<139>" ... )

    dbGetNameNumBit(targetInstanceName) => 154

    could be useful too.

    You can use these same functions on the expression "<*4>(<*16>coladdr<4>,<*16>coladdr_<4>),<*16>coladdr<4>,<*10>coladdr_<4>" too. For example:

    dbGetMemName("<*4>(<*16>coladdr<4>,<*16>coladdr_<4>),<*16>coladdr<4>,<*10>coladdr_<4>" 23) => "coladdr_<4>"

    Regards,

    Andrew.
     

Reply

  • I answered this over on comp.cad.cadence - but for completeness, including reply here too:

    > Hi Robin,
    >
    > Could you explain what data structure do you want to have at the end ?
    > And I think that the code that you wrote above can be replaced with
    > targetInstance = dbGetInstByName(cvId targetInstanceName)
    >
    > At least it is (much) faster.
    >
    > BR,
    > Marcel

    I agree with Marcel - the way you're doing it is terribly inefficient. First of all you're treating the list you have as an array - it is NOT random access, and so you are having to do a sequential search from the beginning of the list each time you call nth(), and so that loop will be doing (roughly) N2/2 (where N is the number of instances). A foreach loop would be better, but best is the dbGetInstByName() function.

    Then you probably want:

    dbGetMemName(targetInstanceName 23) => "my_instname<130>"

    or

    dbProduceMemName(targetInstanceName)
    ("my_instname<153>" "my_instname<152>" "my_instname<151>" "my_instname<150>" "my_instname<149>"
        "my_instname<148>" "my_instname<147>" "my_instname<146>" "my_instname<145>" "my_instname<144>"
        "my_instname<143>" "my_instname<142>" "my_instname<141>" "my_instname<140>" "my_instname<139>" ... )

    dbGetNameNumBit(targetInstanceName) => 154

    could be useful too.

    You can use these same functions on the expression "<*4>(<*16>coladdr<4>,<*16>coladdr_<4>),<*16>coladdr<4>,<*10>coladdr_<4>" too. For example:

    dbGetMemName("<*4>(<*16>coladdr<4>,<*16>coladdr_<4>),<*16>coladdr<4>,<*10>coladdr_<4>" 23) => "coladdr_<4>"

    Regards,

    Andrew.
     

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