@Tim Edwards How does magic extract connections that skip a hierarchy? For example, slot-008 of mpw2 has 8 sram instances placed in

user_proj_example

.

user_proj_example

has no text and thus all extracted ports are automatically generated names.

user_project_wrapper

has met5-met4 connections at the top layer above the sram power rails, but there is no connecting layer at the

user_proj_example

layer. It looks like the sram power rails are not being extracted with connections to the top layer. Any workarounds? It seems that cells without text have issues when extracting with magic. Would it be possible to virtually flatten these cells when extracting?

user_project_wrapper  met5  ----------------
                      via4       |
                      met4      ---

user_proj_example

sram macro pin        met4  ----------------

Magic is supposed to be able to handle that; there would be a

merge

statement in the .ext file that connects down several levels in one merge line. Then

ext2spice

is supposed to find those intermediate levels and assign them as ports to the intermediate level subcircuit. Whether all that works in all cases is anybody's guess---your example suggests the answer is that it doesn't. Flattening in place is a new feature but should work for this. Instead of flattening the entire layout, you can just do

flatten <instance_name> -inplace

, and the instance

<instance_name>

will be immediately replaced by its flattened contents. I do not have a method to flatten by a single level (or specified number of levels) of hierarchy, though. It works quite well for running LVS on the GF I/O and SRAM. I would expect it to work here, as well.

Maybe it’s only a problem on hierarchies that have no text (or no pins) at all, but that’s just a guess.