[Xcircuit-dev] Cadence DFII to XCircuit translator

[R. Timothy Edwards]

Dear Satya,

>> I was wondering if anyone has attempted a Cadence DFII to XCircuit
>> schematic translator. From a cursory glance, it seems rather easy to
>> do. Here are the steps for the translation:
>>
>> 1. dump the DFII schematic using dbWriteSkill
>> 2. read this schematic in a Skill/TCL program and emit XCircuit TCL
>> 3. Load this XCircuit TCL script into XCircuit.
>>
>> If anyone can find faults in this approach, I would like to hear about
>> it.

I made a great deal of headway with an EDIF-to-XCircuit translator, which
I can now use to port Cadence schematics to XCircuit (I don't have the
process going the other way, yet).  The newest version (3.6.42) has the
Tcl script for EDIF reads in the "File" menu.  From Cadence ICFB, I just
need to do "File->Export->EDIF 200...", choose the schematic view of the
cell I want, and otherwise accept the defaults.

I did a Skill dump with dbWriteSkill() that looks something like the
following:

   dbWriteSkill(dbOpenCellView("lib" "cell" "schematic") "filename" "a" "4.4.3")

but the output is inscrutable with references to database hex addresses,
stuff like:

   dbD_0xd51b9e0 = dbCreateNet(dbD_0xca17c2c "downn" nil)

The EDIF output seems to be much more thorough (e.g., it produces all
of the information necessary to draw each of the library components).
Am I missing something in the Skill output?  I get the feeling I would
have to separately dump each library with a dbWriteSkill() call.  I did
notice that not everything in Cadence translates perfectly through EDIF;
for example, the voltage and current sources are drawn with ellipses,
which EDIF (at least not EDIF 2.0.0) doesn't support.  I also couldn't
figure out how the instance properties relate to the text that shows
up in the Cadence schematic---it dumps a bunch of text lines with
text values like "cdsParam(1)", where it is clear from looking at the
schematic that the device width (for example) gets substituted there,
but this cannot be derived from anything in the EDIF output.

It looks like you don't need a license to get EDIF 2.0.0 output, but
you do to get EDIF 3.0.0 output.  It's possible that whatever level of
support we got for Cadence comes with a license for EDIF 2.0.0 whether
or not you ask for it.

Hopefully over the next week I can work on some other format translation
routines.

					Regards,
					Tim

+--------------------------------+-------------------------------------+
| Dr. R. Timothy Edwards (Tim)   | email: tim.edwards at multigig.com     |
| MultiGiG, Inc.                 | web:   http://www.multigig.com      |
| 100 Enterprise Way, Suite A-3  | phone: (831) 621-3283               |
| Scotts Valley, CA 95066        | cell:  (240) 401-0616               |
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