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CadenceTM Compatibility

Limited compatibility with Cadence VirtuosoTM is available on two levels. First, technology, display resource (DRF), and layer mapping files can be read directly by Xic. These files are generally provided in vendor-supplied process design kits intended for use with Cadence Virtuoso. Second, the OpenAccess plug-in allows Xic to access the Cadence libraries directly. Designs can be loaded into Xic, however presently they cannot be returned to Virtuoso without losing data required by Virtuoso.

For export to a Cadence environment, the !dumpcds command will create compatible technology and DRF files based on the Xic technology file in use.

Import of a Cadence technology environment is handled by three keywords which are given in the Xic technology file. In fact, a minimal technology file can consist of little more than these keywords. The keywords should appear in the order given, but otherwise can appear anywhere in the Xic technology file.

ReadDRF drf_file
This reads the display resource file (DRF), which creates tables of layer colors, fill patterns, and similar for use in displays.

ReadCdsTech techfile
This will read a Virtuoso ASCII technology file. The technology file contains the layer definitions, and usually quite a lot of technology information. From this, many of the Xic design rules and extraction keywords can be obtained.

ReadOaTech library
This will obtain Virtuoso technology information directly from OpenAccess. The library is an OpenAccess library, listed in the lib.defs or cds.lib file. This obtains technology information by use of the OpenAccess plug-in. There should be no reason to use both this and ReadCdsTech, as they should retrieve the same information.

ReadCdsLmap filename
The filename is the path to a Virtuoso layer mapping file. This provides GDSII layer/datatype numbers for the layers. This must appear in the Xic technology file after ReadCdsTech.

An Xic technology file can consist of these statements only. This will set the layers and their colors, fill patterns, and some or all of the electrical, extraction, and design rule information.

When a technology file is written with the Save Tech command, it will have the usual format and the lines described above are not included in the new file.

The ability to read the Lisp/Skill file format used by Virtuoso is provided by an internal Lisp parser. The parser is available to run general scripts through the !lisp command, though this has limited utility at present.

In the technology file, is is sometimes useful to enable debugging output from the Lisp parser. The following keyword enables this.

LispLogging [y/n]
If this boolean keyword is set in the technology file, a log file will be generated when the Lisp parser is used. This can be used to track down issues when parsing Virtuoso-style input files. Asserting this keyword is equivalent to setting the Lisp logging in the Logging Options panel from the Help Menu, which otherwise can't be done before the technology file is read on program startup.

next up previous contents index
Next: The Lisp Parser Up: Parameterized Cells and Vias Previous: Connecting to PyCell Studio   Contents   Index
Stephen R. Whiteley 2022-05-28