Hello @Tim Edwards @Stefan Schippers, I have a quick question for those of you who may have experience with transistor models generated by OPENVAF (.osdi files), have any of you managed to use them with XSCHEM+ngspice? Would any of you be able to share your knowledge or tips on successfully using these models together?

You can look at

sky130_tests/tb_reram.sch

if using the sky130B (reram enabled) process variant. basically this is the testbench netlist:

** sch_path: /home/schippes/.xschem/xschem_library/xschem_sky130/sky130_tests/tb_reram.sch
**.subckt tb_reram
V1 net1 0 PWL (0 0 0.25u 1.8 0.5u 0 0.75u -1.8 1.0u 0.0)
.save i(v1)
XR1 TOP 0 sky130_fd_pr_reram__reram_cell Tfilament_0=3.8e-9
Vreram net1 TOP 0
.save i(vreram)

.control
  save all
  tran 0.1n 1.5u
  write tb_reram.raw
.endc

**.ends

.subckt sky130_fd_pr_reram__reram_cell TE BE Tfilament_0=3.3e-9 area_ox=0.1024e-12
N1 TE BE nFilament sky130_fd_pr_reram__reram_model
.ic v(nFilament)={Tfilament_0*1.0e9}
.ends sky130_fd_pr_reram__reram_cell

.model sky130_fd_pr_reram__reram_model sky130_fd_pr_reram__reram_module area_ox=0.1024e-12  area_ox
+ = 0.1024e-12  Tox = 5.0  Tfilament_max = 4.9  Tfilament_min = 3.3  Eact_generation = 1.501
+  Eact_recombination  = 1.500  I_k1  = 6.140e-5  Tfilament_ref = 4.7249  V_ref = 0.430  velocity_k1 = 150
+ gamma_k0  = 16.5  gamma_k1  = -1.25  Temperature_0 = 300  C_thermal = 3.1825e-16
+ tau_thermal = 0.23e-9  t_step = 1.0e-9  smoothing = 1e-7  Kclip = 200

.control
pre_osdi /home/schippes/share/pdk/sky130A/libs.tech/ngspice/sky130_fd_pr_reram__reram_module.osdi
.endc

.end

From above netlist: • You need to compile the .va verilog model into an osdi object using the openvaf compiler • place the .osdi object somewhere • load it using the

pre_osdi

ngspice command • Instantiate the OSDI device using the 'N' reference designator (

N1

in above example), that is linked to a .model, that sets some parameters and points to the verilogA module (

sky130_fd_pr_reram__reram_module

in the example). See ngspice manual: 13.3 How to create and apply OpenVAF models

Thank you for the information.