Integration between Cadence design flows and foundries' design kits

Dear all, I am new to the Cadence design flow. A few months ago I
installed and setup myself the following:

1. Solaris 10 (running on a SUN sparc platform)
2. Cadence IC package v5.0.33, acquired through EUROPRACTICE -no
Sourcelink support!
3. AMS HitKit v3.60B (for creating schematics I use the "ams_cds"
script with the following options: "ams_cds -techfile c35b4 -mode fb").

Al these software seems to be working just fine (no licensing problems
or the like), and so far I have completed a full-custom analog design
at the schematic entry level using Virtuoso Composer and the Analog
Design Environment for simulation. But before proceeding into the
layout and further stages of the design flow, I need to solve the
following problems (please note that I am only talking about full
custom analog design - I am not planning to use synthesis tools,
standard cells, automated place and route, etc.; whose mastery I reckon
might be rather tough!):

1. I have no idea about how exactly the integration between the Cadence
tools and the design kit is performed. At the schematic entry level, I
though that this was accomplished by simply using the appropriate MOS
model files for the instances in the schematic, but I was unable to
find information (i.e. a guide) about which components are included in
the design kit and how they are associated with the models. I even had
to proceed by trial and error to find the most basic active components
(nmos4 and pmos4), but I am sure there should be a resource somewhere
explaining the contents of the libraries in the design kit and the
models associated with them.

2. I don't understand what the different "modes" of the design kit
mean. The AMS hitkit documentation only mentions that the following
modes exist (but it doesn't explain exactly what the differences
between them are, the Cadence tools they interact with, when to use
which, or in which order they should be used!):

fb (for front end back end), ms (for mixed-signal), msfb (for mixed
signal front-back), ds (digital schematic), ly (for layout), lyp (for
layout plus), ca (for cellEnsemble/Preview).

For instance, after successfully simulating my schematic, which mode of
the design kit should I use in order to create the layout (full
custom)? ¿ly? ¿lyp? ¿what are the differences between these two?.

3. My final goal is to produce GDSII files ready to be sent to the
foundry for fabrication, but I am unaware of the exact steps one should
follow for this purpose within the Cadence design flow (there exist so
many tools and for so many different cases that I have gotten really
confused!) What I need to known are the detailed steps that should be
followed in order to go all the way from schematic level entry down to
the GDSII files, for a real implementation.

4. Is there any official chart for the different design flows that can
be implemented with Cadence? Also, is there a formal definition of what
exactly is meant by "front end", "back end" and "front-back", and what
steps of a design flow they comprise?.

Thanks so much for any help regarding these topics.
Best regards.

 

The mode "fb" allows you to run the tools from the front-end design flow
and the tools from the backend design flow.

Front-end tools are the ones that deal with schematics, netlists,
simulation. No layout information is needed.
For digital design flows the logic synthesis is in this part of
the flow.

Backend tools are dealing with all information related to layout.
Layout synthesis, layout edition, placement, routing, DRC, extraction,
parasitics simulation, layout finishing, etc ...

You should ask your design-kit provider to give you access to a
training on the design-kit.
If you are in Europe, there will be one planned in March
15th and 16th in Sweden :
http://www.csee.ltu.se/index.php?subject=asic

Regards,
==============
Kholdoun TORKI
http://cmp.imag.fr
==============

 

Dear Kholdoun,

Thanks a lot for your response. Unluckily, I live in South America, so
it is always a little difficult for us to attend live seminars on EDA
tools and the like. Also, since we get the Cadence suite from
EUROPRACTICE, we have a rather limited support plan. Nevertheless, I
will try to contact them to see if they can help by providing some
information.

Thanks again for your appreciated help!

PS. Would there be in the web any documentation about Cadence Design
flows that could help?