Virtuoso Inherited Connections Tutorial (part 1)

Good news.

SUMMARY:
Inherited Connections Tutorial (part 1), including layout & physical
verification & creation of LEF abstracts & DFII abstracts ...

DETAILS:
The good news is that part 1 of the new "Virtuoso Inherited
Connections Flow Guide" (containing a small sample 180nm design &
design kit with inherited connections) was just released today on
Sourcelink for Customer use!

You can pick up the design, design kit, & documented flow at:
http://sourcelink.cadence.com/docs/files/Tutorials/inheritedconnectiontutorial.html

Here is the wording at that URL if you're unfamiliar with INHERITED
CONNECTIONS:

Inherited connections are an extension to the connectivity model that
allow you to create signals hierarchically and to override their names
for selected branches of a design hierarchy. This flexibility allows
you to design:

* Parameterized power and ground signals
* Overridable substrate connections
* Multiple power supplies for a design

Download the tutorial database and the "Virtuoso® Inherited
Connections Flow Guide" manual to learn more about using inherited
connections with Cadence tools. The manual contains illustrations and
step-by-step instructions that show how inherited connections let you
selectively override signals in designs created with the Virtuoso®
Schematic Editor, and how those connections are available to other
Cadence tools across the design flow.

Download the Tutorial on UNIX/Linux (File size: 15MB)

Coming Soon
The Virtuoso Inherited Connections Flow Guide manual is a
work-in-progress.
We will be extending its depth and breath and plan to cover more of
the complete design process in the future. Please check this location
on SourceLink again for the next version, to learn about:

* The difference between implicit terminals and explicit pins
* How and when to use implicit terminals versus explicit pins
* Inherited connections in AMS Designer using supply sensitivity
* Interaction with the verification environment (ASSURA LVS) or
with parasitic resimulation

John Gianni
Director, Flow Engineering

Nothing I post to the USENET is company ordered nor sanctioned.

 

That is indeed very good news.
I just tried out that flow guide and it's absolutely wonderful!

It only took me a few hours to zip right through its 122 pages and
simple resistor and inverter based test cases. I'd recommend CAD
engineers take this freebie from Cadence, if not for the inherited
connections, then for the flow itself.

The old "inhconn.tar.Z" tutorial, shipped with the Opus software for
ages, didn't go any farther than schematic simulation. Since
everything works with schematics, that wasn't far enough in the flow.

This new flow tutorial takes the explicit inherited connections
through layout and farther to the creation of LEF for place and route.
That's a BIG improvement on the old inhconn tutorial. Thanks Cadence
flow guys for making it available on Sourcelink.

I noticed the supplied generic process design kit is a subset of the
complete GPDK180 available on the crete.cadence.com web site. Also, I
noticed it has netset properties which Artisan doesn't have. That's
probably a good idea (for tutorial size & portability reasons) - but
someone should tell Artisan (ok ARM) that they should add inherited
connections to their standard cell libraries.

I also noticed this new inhconn tutorial required the latest versions
of Opus software. I suspect that's because bugs were fixed in
inherited connections. I used IC5141 on Linux and it worked fine for
me. I tried in an older version of IC5033 FCS and I ran into issues.
So, I guess the recommendations in the document are real.

Thanks for caring about us.

 

It *is* nice. Well done. About time too.

We struggled with explicit inherited connections for years before
realizing implicit is the way to go. This just reinforces our
decision.

I just wish Cadence would create these flow tutorials more often.

 

Is there any way to acces the documentation without having access to
sourcelink?
I work with cadence supplied by europractice and I would really like
to have that updated tutorial.

Manuel

 

Sorry ... I was out on vacation ... just getting through all my emails
....
I'm not sure the best way to get you the tutorial as I am not familiar
with "europractice". I suggest you contact whomever you normally deal
with at Cadence and have them contact me or the inherited connections
task force. (They'll know who I am.)

Also, for everyone else, it's no longer in the "Whats New" section
of Sourcelink, so, save this URL for future reference:
http://sourcelink.cadence.com/docs/files/Tutorials/inheritedconnectiontutorial.html

Based on Customer input, this is the second-update to the inherited
connections tutorial, with a tiny 180nm design kit & sample designs
included. Let us know through the feedback button what you think of
it.

John Gianni