@Mitch Bailey @Tim Edwards I'm extracting my test.gds which contains two instances inside, if I extract two instances separately, there wouldn't be any

VSUBS

ports in their spice files and the lvs check passed for both. While if I just put them (bgr_final, bgr_gen7) together even without any connection in

test.gds

and get the

test.spice

(extracted from layout test.gds), there would always be some weird VSUBS ports, and this leads to the lvs mismatch. I attached the test.gds, test.spice, my source netlist test_source.spice (two instances bgr_final_0, bgr_gen8_0; name changes a bit from layout). After debugging, I still have no idea about the causation of the auto-generated VSUBS port. Looking forwards to your advice! My guess is this somehow relates to the psubstrate connection, as all VSUBS ports only adds in psubstrate-(should) to-GND devices.

@Yueting Li: I just did an extraction from the posted test.gds and I get the common substrate VSUBS in the netlist. What version of magic are you using?

@Tim Edwards I used magic 8.3.285, I got VSUBS in

test.spice

as well, what does common VSUBS mean?

What Tim was saying is that when extracted with the latest version of magic, the VSS and VSUBS nets are connected. Can you try with the current magic version?

Thanks Mitch, I'll update the magic version and try again!