#450 Error simulating some MOSFETs in my own xschem but successful in open_pdk xschem_tests Issue created by JacobEFO Hi, I am currently battling some funky issues. I should have successfully installed all the tools, in the right manner and without errors. What I initially did was run the open_pdk xscheem tests, running the

test_nmos.sch

and

test_res.sch

benches that both successfully run and generate results, both with

sky130A

and

sky130B

. When I then make my own schematic with a single primitive I get some simulation issues with

nfet_01v8

,

nfet_03v3_nvt

and

nfet_05v0_nvt

, both in 4T and 3T models. You can see the issue below (and similarly for the other types of devices):

Warning from checkvalid: vector @m.xm1.msky130_fd_pr__nfet_0v18[ib] is not available or has zero length

and it does not generate my

.raw

file. If I use the

nfet_20v0

I have no problems simulating whatsoever. You can see an example of the faouoeg netlist:

** sch_path: /home/jefo/MEGA/Electronics/Xschem/hello_world_desktop/nfet_01v8.sch
**.subckt nfet_01v8
Vmeas P net1 0
.save i(vmeas)
XM1 net1 net1 G G sky130_fd_pr__nfet_01v8 L=0.5 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
**** begin user architecture code


.option savecurrents
vp p 0 1.8
vg g 0 0
.control
save all
dc vp 0 1.8 0.005
write nfet_01v8.raw
.endc


.lib /home/jefo/cad/share/pdk/sky130B/libs.tech/combined/sky130.lib.spice tt
**** end user architecture code
**.ends
.end

And the successful one:

** sch_path: /home/jefo/MEGA/Electronics/Xschem/hello_world_desktop/nfet_01v8.sch
**.subckt nfet_01v8
Vmeas P net1 0
.save i(vmeas)
XM1 net1 net1 G G sky130_fd_pr__nfet_20v0 L=0.5 W=40 m=1
**** begin user architecture code


.option savecurrents
vp p 0 1.8
vg g 0 0
.control
save all
dc vp 0 1.8 0.005
write nfet_01v8.raw
.endc


.lib /home/jefo/cad/share/pdk/sky130B/libs.tech/combined/sky130.lib.spice tt
**** end user architecture code
**.ends
.end

I have tried removing all the settings for parameters such as

ad

etc, moving around the

mult

,

m

,

nf

and so forth to no avail and I am at a loss at the moment. This issue occurs both in a MacOS v.12 installation and this one on my Fedora. One thing I noticed in the

models_fet.spice

-file is the definition for the 20 V NMOS looks vastly different from the failing NMOS devices as you can see below:

.subckt  sky130_fd_pr__nfet_20v0_iso d g s b sub  w=60u l=2u sa=0 sb=0 nf=2 mult=1
.subckt  sky130_fd_pr__nfet_20v0_nvt d g s b  w=60u   sa=0 sb=0 sd=0  nf=2 mult=1
.subckt  sky130_fd_pr__nfet_g5v0d16v0 d g s b mult=1
.subckt  sky130_fd_pr__nfet_g5v0d16v0_base  d g s b  mult=1
.subckt  sky130_fd_pr__nfet_20v0 d g s b  w=60u  sa=0 sb=0 sd=0  nf=2  mult=1
.subckt  sky130_fd_pr__nfet_20v0_zvt d g s b  w=60  sa=0 sb=0 sd=0  nf=2 mult=1
.subckt  sky130_fd_pr__esd_nfet_05v0_nvt d g s b mult=1
.subckt  sky130_fd_pr__nfet_01v8_esd d g s b mult=1
.subckt  sky130_fd_pr__esd_nfet_g5v0d10v5 d g s b mult=1
.subckt  sky130_fd_pr__nfet_01v8_lvt  d g s b  mult=1
.subckt  sky130_fd_pr__nfet_03v3_nvt  d g s b  mult=1
.subckt  sky130_fd_pr__nfet_05v0_nvt  d g s b  mult=1
.subckt  sky130_fd_pr__nfet_01v8  d g s b  mult=1
.subckt  sky130_fd_pr__nfet_g5v0d10v5  d g s b  mult=1
.subckt  sky130_fd_pr__pfet_g5v0d16v0 d g s b mult=1
.subckt  sky130_fd_pr__pfet_g5v0d16v0_base  d g s b  mult=1
.subckt  sky130_fd_pr__pfet_20v0 d g s b  w=50u l=2u  nf=2   sa=0 sb=0 sd=0  mult=1
.subckt  sky130_fd_pr__esd_pfet_g5v0d10v5 d g s b mult=1
.subckt  sky130_fd_pr__pfet_01v8_hvt  d g s b  mult=1
.subckt  sky130_fd_pr__pfet_01v8_lvt  d g s b  mult=1
.subckt  sky130_fd_pr__pfet_01v8  d g s b  mult=1
.subckt  sky130_fd_pr__pfet_g5v0d10v5  d g s b  mult=1

Found with

rg subckt models_fet.spice

in the installed location

/share/pdk/sky130B/libs.tech/combined/continuous

. Can you possibly see where I go wrong here? RTimothyEdwards/open_pdks