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The Export Control Button: Conversion - Export Panel

The Conversion - Export panel is brought up with the Export Control button in the Convert Menu. This panel allows various flags and variables that are specific to file output to be set, and also allows initiation of actual output operations. At the top of the panel are several buttons which set internal flags.

Strip For Export
When the Strip For Export button is active, converted output will contain physical data only, and will contain no Xic extensions.

Within Xic, archive file representations consist of two sequential records in each file. The first record is the physical information, and the second record contains the electrical information. These files should be compatible with other CAD systems, as these files are generally expected to have only one record, and consequently the electrical information may be ignored. However, one should not count on this. When the Strip For Export button is active, Xic will convert only the physical information when explicitly (i.e., using the operations from the Conversion - Export panel, and not the Save and Save As buttons) converting to an archive format. The Strip For Export setting also applies to the ToCGX, ToCIF, ToGDS, and ToOASIS script functions. This creates a file which should be an absolutely conventional physical layout file. The Strip For Export button should be active when creating a file for use in generating photomasks. Note that the electrical information can never be recovered from a stripped file.

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

Don't convert invisible layers
There are separate check boxes that apply to physical and electrical modes. When active, only layers that are currently visible, as selected with button 2 in the layer table, will be written when using the operations initiated from the Conversion - Export panel. This is the method by which certain layers can be eliminated from generated output. When this button is not active, all Xic layers will be converted.

This feature can also be enabled by setting the variable SkipInvisible with the !set command.

The remaining settings on this panel apply to all generated output, and not just to output initiated from this panel.

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.

Cell Name Mapping
This group of controls manages the cell name aliasing feature (see 9.1). This does not apply to native cell file output, and the prefix/suffix modifications apply only when the operation is initiated from this panel or a script function.

GDSII and OASIS: skip layers without Xic to GDS 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.

OASIS: use compression
When active, created OASIS files will use compression. The contents of each CELL record and name table will be placed in a CBLOCK record, which should reduce file size. When not active, no compression will be used.

NOTE: compressed OASIS files are not compatible between the present release and release 2.5.57 and earlier. Compressed OASIS files from the present release are compatible with other tools that follow the OASIS specification.

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

OASIS: use string tables
When active, all strings including cell names, properties, and labels are saved in indirection tables. Throughout the file, strings will be referenced by number. This should reduce file size. When not active, each string will be saved locally for each reference.

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

OASIS: find repetitions
When active, an attempt is made to identify identical objects that are placed in multiple locations, and use REPETITION records in OASIS output instead of writing multiple object records. This should reduce file size, but can be compute-intensive. When not active, no attempt is made to use REPETITION records, except for cell arrays.

See the description of the OasWriteRep variable, which controls the use of REPETITION records in OASIS output. This variable can be set explicitly to fine-tune the use of REPETITION records. The check box sets/unsets this variable as a boolean.

OASIS: write crc checksum
When active, a cyclic-redundancy (CRC) checksum is added to OASIS output files (OASIS validation method 1). When not active, no checksum is added.

See the description of the OasWriteChecksum variable, which controls the validation method in OASIS output. This variable can be set explicitly to use byte-sum checksum validation (OASIS validation method 2). The check box sets/unsets this variable as a boolean.



Subsections
next up previous contents index
Next: CIF Dialect Up: The Convert Menu: Data Previous: GDSII Layer Mapping   Contents   Index
Stephen R. Whiteley 2006-10-23