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GDSII Settings

GDSII version number, polygon/wire vertex limit
This option menu effectively sets the GdsOutLevel variable. This determines the release number given in the GDSII file, and also sets limits on the number of vertices allowed in polygon and wire objects included in the file. If an object in the database has too many vertices, it will be written to the file as multiple objects, which cover the same area. The default is GDSII format release 7, which allows up to 8000 polygon or path vertices. It may be necessary to use one of the format release 3 choices if the file is to be read by older software.

Skip layers without Xic to GDSII layer mapping
When this button is active, layers without a GDSII output mapping will be ignored when producing GDSII or OASIS output, though a warning will appear in the log file. Otherwise, this is an error which terminates the operation.

This mode can also be enabled by setting the boolean variable NoGdsMapOk with the !set command.

GDSII files can be gzip compressed. Such files are recognized automatically on input, and can be coerced as output by giving a ``.gz'' suffix to the file name.

Accept but truncate too-long strings
The GDSII and CGX formats use a 16-bit integer to store record size, limiting the size of records to 64KB. This prevents storage of stings longer than this. By default, an attempt to write such a string to a GDSII or CGX file will generate a fatal error, aborting the operation. If this check box is set, overrunning strings will be truncated to maximum possible length, and the operation will continue without error. Warnings will appear in the log file, however.

The check box tracks the state of the GdsTruncateLongStrings variable.

Unit Scale
This entry area contains a value that will multiply the default values of the ``machine unit'' and ``user unit'' parameters which are used in the GDSII file, and all coordinates in the file will be divided by this value. The default values for these parameters are
machine unit: 1e-6/resolution
user unit: 1.0/resolution
where resolution is the internal resolution, which defaults to 1000 per-micron, but can be changed with the DatabaseResolution variable. It is not likely that the user will need to set this, and unless the user understands the implications it is recommended that the default value (1.0) be used. This entry area is an interface to the GdsMunit variable.

next up previous contents index
Next: OASIS Settings Up: The Export Cell Data Previous: The Export Cell Data   Contents   Index
Stephen R. Whiteley 2022-05-28