Add `ihp-sg13cmos5l`

[dnltz]

Description

Would be great if the ihp-sg13cmos5l PDK is also available via ciel.

What is currently blocking us? Just no one started to work on this task or are there any technical issues?

Proposal

No response

[mole99]

I fully agree. Unfortunately, adding ihp-sg13cmos5l is actually not straightforward.

It is the first PDK that is in a separate repository with separate hashes, but is still part of the ihp-sg13 PDK family. So it will require some changes in ciel to be properly supported.

We also need to rename the current ihp-sg13g2 PDK family to ihp-sg13.

Alternatively, we actually keep ihp-sg13g2 and ihp-sg13cmos5l as two separate PDK families with their own PDK. This would make sense because they do not share hashes, but it's not really a nice solution...

Another solution would be for https://github.com/IHP-GmbH/IHP-Open-PDK to add ihp-sg13cmos5l as a submodule to the root.

This way, we would only need a single hash of IHP-Open-PDK to describe both PDK variants.
If you manually clone IHP-Open-PDK then PDK_ROOT=IHP-Open-PDK and PDK=ihp-sg13g2|ihp-sg13cmos5l.
It would then actually make sense to move ihp-sg13g2 into a separate repository and add it as a submodule to IHP-Open-PDK.
IHP-Open-PDK would then be the PDK gateway.

Not sure what Krzysztof would say about that :)

[mole99]

Just to clarify, the current situation is as follows:

pdk-family: gf180mcu
pdk-variants: gf180mcu[A|B|C|D]

pdk-family: sky130
pdk-variants: sky130[A|B]

pdk-family: ihp-sg13g2
pdk-variants: ihp-sg13g2

You see the issue with IHP ;)

It should be:

pdk-family: ihp-sg13
pdk-variants: ihp-sg13[g2|cmos5l]

But we can only do this if we can describe both PDK variants with one hash.

[dnltz]

I see. Thanks for clarification.

I think adding cmos5l as submodule is an improvement to the current structure and easy to fix.

[RTimothyEdwards]

The structure of the IHP Open PDK repository suggests that the original intent was to have both process variants in the same parent repository. Especially where there are symbolic links in cmos5l pointing to ../../ihp-sg13g2/.

[donn]

Alternatively, we actually keep ihp-sg13g2 and ihp-sg13cmos5l as two separate PDK families with their own PDK. This would make sense because they do not share hashes, but it's not really a nice solution...

This would be the simplest way but PDK vs PDK variant vs PDK family is confusing as-is

[dnltz]

The structure of the IHP Open PDK repository suggests that the original intent was to have both process variants in the same parent repository. Especially where there are symbolic links in cmos5l pointing to ../../ihp-sg13g2/.

Yes, I basically forked the IHP-Open-PDK and included the ihp-sg13cmos5l via a single commit (without any changes in the cmos5l directory).

[mole99]

Krzysztof is looking into adding ihp-sg13cmos5l as a submodule to IHP-Open-PDK.