Accessing cell instance from subcircuit

As I understand at the moment the extract subcircuits always have names which just correspond to their DB index. I would like to assign them more useful names for myself. My cell instances have user properties and I could use them to add useful names to the extracted subcircuits. However, the subcircuit object exposed in the API does not have any property with a reference to the cell instances. However, the layout browser GUI does have such reference somehow (since the view will jump if i select a subcircuit).

How could I get a reference to cell instance in the original layout from an extracted SubCircuit?

I know how to get a reference to the cell, but that does not help if I have multiple instances of the cell.

Comments

  • Humble ping.

  • Hi,

    currently there is no link to a cell instance. The names are there only to represent subcircuit names from Spice (or other) netlists. You can basically identify a subcircuit through it's transformation (placement), that's all.

    In a standard context, layout instances don't have names, hence there is not data path provided.

    The user property translation into subcircuit names can be coded in the netlist extractor, but there are some basic complications like the differentiation between source and internal layout and the potential generation of cell variants during certain preprocessing operations.

    Another solution is to utilize the transformation information, build a map of instance transformation/cell names vs. instance names and assign the properties in a post-extraction step.

    Matthias

  • The names are there only to represent subcircuit names from Spice (or other) netlists.

    Yes. In my netlist visualization it helps to have net names.

    Another solution is to utilize the transformation information, build a map of instance transformation/cell names vs. instance names and assign the properties in a post-extraction step.

    I see. Thank you for the answer! Will give it a try. A fundamental problem with this is non-uniqueness if network elements on different layers are at the exactly the same location.

  • Depending on how many variants, perhaps you want to
    use cell copy and rename, in the Navigator pane, to make
    the uniqueness by naming and retargeting the instance?

Sign In or Register to comment.