@Stefan Schippers @Tim Edwards @Mitch Bailey Is there a way to generate CDL netlist from xschem schematic/spice file which can be used later in LVS?

Are you referring to magic/netgen LVS or some other tool? For magic/netgen, Under the simulation menu, be sure the

LVS netlist: Top level is a .subckt

is checked before pressing the

Netlist

button on the top right.

Yes I will be using magic/netgen LVS

@Pranav Lulu xschem generates a netlist suitable for LVS if the option

Simulation->LVS netlist: top level is a subckt

is checked. This modifies slightly the netlist format for schematic vs layout (LVS) comparison. If some components need a special netlist format for LVS a dedicated netlist rule can be given in the symbol with the

lvs_format

attribute. You can copy this attribute from the format attribute used for spice netlisting and make the required changes.

@Mitch Bailey @Stefan Schippers Thanks!!

@Pranav Lulu After Nov.24th xschem and the xschem_sky130 symbols have been modified by adding a '`lvs_format`' attribute (in addition to

format

that sets the spice netlisting rule) that defines the netlisting rule if

Simulation->LVS netlist: top level is a subckt

is selected. In LVS mode the netlist for a mos transistor looks like:

XM1 net1 G1v8 S B sky130_fd_pr__nfet_01v8_lvt L=0.15 W=1 nf=1 m=1

instead of:

XM1 net1 G1v8 S B sky130_fd_pr__nfet_01v8_lvt L=0.15 W=1 nf=1 ad='int((nf+1)/2) * W/nf * 0.29' as='int((nf+2)/2) * W/nf * 0.29'

+ pd='2*int((nf+1)/2) * (W/nf + 0.29)' ps='2*int((nf+2)/2) * (W/nf + 0.29)' nrd='0.29 / W' nrs='0.29 / W'

+ sa=0 sb=0 sd=0 mult=1 m=1

so area / perimeter params are not generated. The device line contains

L, W, nf and m

which should be enough for checking vs layout. @Tim Edwards if netgen needs also area and perimeter for S/D regions let me know, if it does do i need to present the calculated values in the LVS netlist (or does netgen understand equations?)

@Stefan Schippers Thanks! I guess I need to update Xschem. What else do I need to update?

you get updated xschem_sky130 models by updating

open_pdks

. If you don't want to go through the rather long

open_pdks

update then you might want to clone the xschem_sky130 repository and copy the

sky130_fd_pr/

directory replacing the one in the pdk installation

/..../share/pdk/sky130A/libs.tech/xschem/sky130_fd_pr

@Stefan Schippers Okay got it.