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Input/Output

The technology-specific information used by Xic is maintained in a single human-readable file. Most of the parameters set by the technology file can be set or reset from within Xic, and an updated technology file can be easily generated.

Xic can read or write files in several formats. These include

GDSII
The industry-standard binary data format.

OASIS
A new standard intended to replace GDSII and is far more compact.

CIF
An ancient ASCII data format, still in use occasionally.

CGX
A more compact replacement for GDSII developed by Whiteley Research (and placed in the public domain). It still uses fixed-sized integers, so is not nearly as compact as OASIS, but is simple to generate and parse.

Native
A CIF-like cell-per-file format.

OpenAccess
If present, Xic can read and write to an OpenAccess database, including the databases provided with Cadence Virtuoso and Ciranova PyCell Studio.

Any files in these formats can be read directly into Xic, whether or not the current technology matches. In fact, it is possible (and sometimes desirable) to start Xic with no technology file. As the file is read, Xic will add layers as necessary to represent the file. After changing layer colors and fill patterns as desired, a new technology file can be dumped.

Files can be read into the Xic database, and later written to disk in any of these formats. The default is to write in the same format as the original file.

In addition, format conversions can be applied directly, bypassing the database load. While converting, windowing operations (clipping), scaling, or flattening can be applied. Since Xic uses 64-bit file offsets, the direct conversions can be applied to huge files, even with 32-bit Xic binaries and modest memory.


next up previous contents index
Next: Design Rule Checking Up: A Quick Tour of Previous: Layout Editing   Contents   Index
Stephen R. Whiteley 2017-04-09