sky130A support and latest release

[shalan]

Hi All,

What is the latest stable release of electric and where to find it. 

Also, what is the current status of Sky130A PDK support.

Thanks.

--shalan

[Gavin Abo]

As far as I know, Electric 9.07 released in 2016 is still the latest
stable binary release, which is at:

https://www.staticfreesoft.com/productsFree.html

However, it looks the source code in the trunk has some changes from 4
weeks ago:

http://svn.savannah.gnu.org/viewvc/electric/

That source code is likely stable but you would have to build the code.

The different build methods for the code are described at:

https://www.staticfreesoft.com/jmanual/mchap01-04-01.html

I'm not aware of the current status of the Sky130A PDK support. If one
of the others in the list is using that, they might answer you later
about that.

Kind Regards,

Gavin

[Adam Joseph]

On Wed, 9 Jun 2021 21:36:03 -0700 (PDT)
"'shalan' via Electric VLSI Editor" <electr...@googlegroups.com>
wrote:

> Also, what is the current status of Sky130A PDK support.

Hello, Shalan,

My company, Western Semiconductor, wrote the initial sk130 PDK for
Electric which is still available and you are welcome to use it:

https://gitlab.com/westernsemico/com.westernsemico.vlsi

We did this before Skywater announced the very unusual tape-in
requirements for Google-subsidized runs, especially the requirement
that subsidized runs be wrapped with the Skywater Management Engine.

After those requirements were released, I realized that targeting the
Google-subsidized runs is not a good use of engineering resources. The
engineering time required to meet a tape-out costs many multiples of
a 130nm MPW through other companies (e.g. MOSIS or IMEC).

I have explained this to Skywater and asked them to inform me as soon
as fully-paid and reserved MPW slots are available for purchase. They
seemed sympathetic and said they would let me know when that happens.

Unfortunately further work on the PDK by Western Semiconductor will
have to wait until paid reservations are offered by Skywater.

Thanks,

- a

[shalan]

Hi Adam,

Thanks for the pointers. I will try them out. I am considering using it for a class I am teaching this summer. Also, I will be happy to help developing it further. What is its current state? what is missing?

Btw, are you on skywaterr-pdk Slack space? If not, you may join @ https://invite.skywater.tools. I think your contributions to the #electric channel will be great.

I am sorry that you did not make use of the Open MPW program. Btw, I helped designing the harness chip (Caravel) being used for this program. Also, I am the architect of OpenLane, the open source digital ASIC flow. I will be more than happy to help you to submit designs to future shuttles. 

Finally, have you seen this: https://www.efabless.com/chipignite/2106Q? I think this is what you are looking for. A commercial MPW for SKY130A. The MPW slot costs less than 10K USD (100 QFN or 300 WCSP parts) with the option to use the full die area the way you want. I recommend that you get in touch with mkk at efabless.com

Thanks.

--mshalan

[Adam Joseph]

On Sat, 12 Jun 2021 12:22:54 -0700 (PDT)

"'shalan' via Electric VLSI Editor" <electr...@googlegroups.com>
wrote:

> Btw, I helped designing the harness chip (Caravel) being used for
> this program.

Thank you for your work on this! I think Caravel is an awesome idea
and an impressive accomplishment. The only thing that is not-awesome
is the fact that it is mandatory to use it as a monolith. I hope that
changes. Really all that should be required is that the UBM and top
metal layer match Caravel in order to allow all the projects to be
WLCSP-packaged in a single run.

> Finally, have you seen this:
> https://www.efabless.com/chipignite/2106Q?

No, I had not seen that. It looked very promising, except:

> How It Works
> ...
> 3. Complete your project using the Caravel carrier-chip design

I would assume from this that using all of Caravel is still mandatory.

However, you write:

> with the option to use the full die area the way you want.

... so perhaps my interpretation of the rules was too pessimistic?

> I recommend that you get in touch with mkk at efabless.com

Thank you; I will send an email to that address for clarification and CC
you. I've also replied to you directly with answers to your other
questions.

- a