Added resistor type short as a custom modification to the device
models. Changed "obslic" (li-m1 contact as an obstruction layer)
to be defined not between obsli and obsm1, but between obsli and
metal1. This is consistent with the use of obsli in the standard
cells with the LEF files generated using the "-toplayer" option,
and allows metal1 to be placed across the power rails and obslic
contacts without generating DRC errors.
diff --git a/sky130/custom/models/short.spice b/sky130/custom/models/short.spice
new file mode 100644
index 0000000..bc5faf0
--- /dev/null
+++ b/sky130/custom/models/short.spice
@@ -0,0 +1,2 @@
+* Resistor model "short" defined with a fixed resistance of 0.01 ohms.
+.model short r r=0.01
