Select schematic instance from instance iterations

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

 

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

 

Marcel Preda wrote, on 03/02/11 10:42:

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) N^2/2 (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.

 

Hi andrew,



Thanks for your reply. I'm just a beginner so don't know these
functions yet. It's like my 3th SKILL script ever

Thats why i taken the most elementary approach. I do realize its not
so magnificient efficient but i thoughed it was the only way. Thanks
for that tip. Will be very handy later

Back to the actual problem, I solved it by making a spectre netlist
and then parsing it. Also not efficient but at that time i saw it as
the only solution

Thanks for the tips,

Robin