open-source-silicon.dev

Hi. When i use netgen to compare netlists, if the top-level file has a subckt wrapper netgen complains that the netlist contains no devices. Is there a way to fix this?

Yes.  There's a syntax `netgen -batch lvs "_filename1 cellname1_" "_filename2 cellname2_" _setup_file output_file_` .  That is, instead of just giving netgen two files to compare, you give it two files _and two cell names_ to compare.  This is the *proper* way to use netgen, because it ensures that you are comparing not just the netlists, but all the pins as well.

It's also convenient because you can compare _any_ two cells down in the hierarchy of the netlists just as well as the top.  Which is useful if you have a huge top level netlist and you want to debug a subcell of it without having to re-extract.

<@U01H2JMLFLL> Does’s Tim’s explanation make sense? Can you share the full command you use for netgen if you have further questions?

Yes thanks <@U017X0NM2E7> it does, thank you <@U016EM8L91B>. All i was missing is the `cellname&lt;n&gt;` after the file names. adding that makes it work as expected. Cheers!

BTW, as `netgen` works with ANY SPICE netlist, it is quite useful for schematic-vs-schematic or layout-vs-layout as well :slightly_smiling_face:

Good point. Although not had a need for that yet