'M' Property Error on Single PNP

[d-m-bailey]

netgen 1.5.264

A single pnp transistor is extracted without an M parameter. Matching to a single pnp transistor in the source spice with an m parameter causes a mismatch. Here’s the reduced layout:

X0 GND GND eg sky130_fd_pr__pnp_05v5_W0p68L0p68 M=8                               
X1 GND GND eu sky130_fd_pr__pnp_05v5_W0p68L0p68                                   

and here’s the schematic

XQ2 vss vss net2 sky130_fd_pr__pnp_05v5_W0p68L0p68 NE=1 m=8
XQ1 vss vss vn sky130_fd_pr__pnp_05v5_W0p68L0p68 NE=1 m=1

and here’s the error message

Netlists match uniquely with property errors.
Circuit 2 bandgap instance sky130_fd_pr__pnp_05v5_W0p68L0p68:Q1 property "m" has no match in circuit 1.

Currently, the NE parameter in the source is ignored in the test setup file. If the NE parameter is removed from the source, no warning message is generated.

To duplicate, export PDK_ROOT and PDK for sky130, then

1. tar xzf test-netgen.tgz
2. cd test-netgen
3. netgen -batch source lvs.script

test-netgen.tgz

You should be able to open the schematic user_analog_project_wrapper.sch in the xschem directory. Note that this is not the original schematic data but has been modified to (almost) match the layout.

[RTimothyEdwards]

@d-m-bailey : Thanks for the bug report and reproducible result. I discovered the reason and why I could not duplicate the issue in a simple test. Occasionally the "M" parameter gets recorded as type double (I forget the reason why), which was happening in this example, and that specific case was not being tested. It is now fixed in netgen version 1.5.265.

[d-m-bailey]

Excellent!

There was another property error in the test data, but that is due to a mismatch in the dummy mosfet counts and is not an issue.