open-source-silicon.dev

<https://github.com/RTimothyEdwards/open_pdks/pull/154|#154 Corrects 3 terminal x-device resistor conversion.>
Pull request opened by <https://github.com/d-m-bailey|d-m-bailey>
Changes 3rd terminal to $SUB=xxx where xxx is the 3rd terminal.

Should resolve the remaining issues with <https://github.com/RTimothyEdwards/open_pdks/issues/59|#59>.

For example, the change to `sky130_fd_sc_hd.spice` would be

Before

```
.subckt sky130_fd_sc_hd__conb_1 VGND VNB VPB VPWR HI LO
R0 VGND LO VNB sky130_fd_pr__res_generic_po w=480000u l=45000u
R1 HI VPWR VNB sky130_fd_pr__res_generic_po w=480000u l=45000u
.ends

```

After

```
.subckt sky130_fd_sc_hd__conb_1 VGND VNB VPB VPWR HI LO
R0 VGND LO  sky130_fd_pr__res_generic_po w=480000u l=45000u $SUB=VNB
R1 HI VPWR  sky130_fd_pr__res_generic_po w=480000u l=45000u $SUB=VNB
.ends

```

Unfortunately, this results in the following LVS property errors. These can be ignored via a netgen setup change which I'll submit later.

```
There were property errors.
sky130_fd_pr__res_generic_po1 vs. sky130_fd_pr__res_generic_po0:
Property $SUB in circuit2 has no matching property in circuit1
sky130_fd_pr__res_generic_po0 vs. sky130_fd_pr__res_generic_po1:
Property $SUB in circuit2 has no matching property in circuit1

```
<https://github.com/RTimothyEdwards/open_pdks|RTimothyEdwards/open_pdks>