- force lower-case layer names to allow CIF/MAG loop (CIF needs
upper-case layer names, MAG doesn't)
- reverted CIF reader to standard
- new options for writer: tech, "zero timestamp".
- file name MUST be consistent with one cell name.
Reason: it's not possible to derive the initial
cell from the given options, so without the file name
being consistent, we can't know what to write there.
Basically the file name rather supplies the path.
The problem is solved by always producing subcircuits for cell
instances, even if there are no connections.
The netlist comparer had to be adjusted too because subcircuits
without pins were used for representing "unknown" subcircuit pairing.
In addition, this patch should lead to a better matching of
parallel subcircuit configurations where two different subcircuits
are entirely parallel.
same_nets, equivalent_pins, same_circuits and same_device_classes
can now be given at the beginning of the LVS script. This will
simplify building universal scripts with the run specific part at
the beginning (one "load" section).
The price are somewhat less specific error messages when something
fails in these methods.
Fake pins: pins that happen because something connects to a cell at an
unexpected position. Such a pin is difficult to find. The solution is
to keep those nets and nur purge them so these nets can be identified
in the layout.
Here: is_floating? will be true only if there are no pins. Hence
nets with pins are not removed. is_passive is introduced for nets -
passive nets are such that don't have elements, but a pin.
Circuits are purged if they only have passive nets.
Consistent behavior for file paths for images too.
Plus: image paths are not kept as absolute paths
inside the session.
This makes regeneration of images stable.
The problem was that with the floating test case, the
ambiguity resolution sometimes assigned the wrong pins
and floating pins/connected pins were swapped.
One option is to make the ambiguity resolver consider
the pin connection state when tenatively evaluating
nodes.
Another option is to put more emphasis on net names
and use them for ambiguity resolution. This has helped
here.