PDN gen appears to silently ignore -starts_with in define_pdn_grid

[jeffng-or]

Subject

Describe the bug

Found with proprietary PDK, but repro's with ASAP7 PDK

If the ASAP7 PDN gen script is updated from:

define_pdn_grid -name {top} -voltage_domains {CORE} -pins {M6}

to:

define_pdn_grid -name {top} -voltage_domains {CORE} -pins {M6} -starts_with POWER

Shouldn't the bottom-most M1 rail be VDD and not VSS? It's not:

Expected Behavior

If the -starts_with is ignored for some reason, we might want to log it and why.

Environment

orfs git commit tag: c9c22caf9bf9cfe46c5a4236c6ec7e7ae9863cc3

To Reproduce

mkissue tarball: https://drive.google.com/file/d/1nWdbR5GFE3S2eBDfHjN5aCBOEunPQA_r/view?usp=drive_link

Relevant log output

Screenshots

No response

Additional Context

No response

[maliberty]

I'm assuming that is an m1 follow pin strap which has to follow the row orientation. That flag would only have effect on upper non-followpin layers. Probably a warning is needed but not a bug fix.

[maliberty]

I'm guessing you need -flip_sites on initialize_floorplan

[gadfort]

When specified with the followpin definition we already generate a warning. I'm not sure what you want here, since you are specifying something for the grid (which may or may not have follow pins) and what if you specify it with the correct orientation. Unless there is an obvious thing to check, I don't think this needs a warning.