The Conversion panel is brought up by the Convert button in the Convert Menu. This panel is a front end to a number of direct conversion functions which translate an input file into output of another format. These are direct conversions, i.e., the data are converted directly and do not enter the database. This means that there are no memory limitations, and as 64-bit file offsets are used, arbitrarily large files can be translated. It is also possible to perform scaling, data windowing or clipping, and hierarchy flattening while translating.
Conversions can also be performed by reading in a hierarchy and using the explicit output conversion in the Conversion - Export panel.
The input and output file types are selected from the two drop-down menus. The content of the output format menu may change as the input format is selected, as not all permutations are supported. Conversion between any of the archive formats is possible, as is conversion from an archive format to native symbol files. Binary archive files can be translated to a human-readable text representation by selecting ``text'' in the output format menu, which may be useful for debugging corrupted files. The text representation of GDSII files can be back-converted to GDSII format.
There are several check boxes which control details of the output format. The four OASIS controls also appear in the Conversion - Export panel.
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.
This mode can also be enabled by setting the boolean variable OasWriteNameTab with the !set command.
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.
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.
The remaining two check boxes affect the ascii text output from OASIS files.
The Cell Name Mapping group of controls manages the cell name aliasing feature (see 9.1).
The layer change module allows layer filtering and/or mapping to be applied during the read operation (see 9.4). These actions can be performed when:
For input file types that support scaling, the conversion scale factor entry area will be active. A scale factor of .001 - 1000.0 can be entered in this area, and will be applied during the translation.
The Use Window button controls whether or not a rectangular area is to be used. If this button is set, only the objects that intersect this area will appear in the output file. For subcells, only the objects that appear within the window for some instance will be converted in the corresponding cell. The rectangular area can be set with the Left, Bottom, Right, and Top entry areas. These are coordinates, in microns, in the coordinate system of the top-level cell, after scaling is applied. Only geometry that overlaps the window area will be included in the file. However, when viewing the new file, geometry in subcells that also exist outside of the window area will be visible, unless the hierarchy is flattened.
If the Clip to Window button is active in addition to the Use Window button, objects will be clipped to the given window. Without clipping, the entire object is retained. With clipping, the objects will be clipped to the window given. Again, unless the hierarchy is also flattened, geometry in subcells that also exist outside of the window will be displayed when viewing the new file.
If the Flatten Hierarchy button is active, the output file will be a flat representation, i.e., all geometry will appear in the top-level cell, which will have no subcells.
If the No Empties button is active, empty subcells and their references will not appear in output. Use of layer filtering and windowing with clipping and not flattening may generate empty cells, and use of this button prevents these from appearing in output.
When using windowing or flattening, best performance is obtained when the input file is not compressed. Resolving offsets into the file requires a lot of decompression which can substantially increase conversion time.
The translation is initiated with the Convert button. The user will be prompted for the name of the input file, and then the name of the output file, or directory for native files.
If the input and output formats are both GDSII or both CGX, and there is no windowing, flattening, scaling, or layer filtering, no parsing will occur. Instead, the file is directly copied, possibly with compression or decompression. The ``.gz'' suffix on the input or output file names indicates whether compression/decompression is applied. Unlike some versions of the standard gzip/gunzip utility, this is applicable to files larger than 2Gb in Xic releases that support 64-bit file offsets.
When generating an archive file and an error occurs. the archive file will normally be deleted. However, if the variable KeepBadArchive is set (with the !set command) the output file will be given a ``.BAD'' extension and retained. This file should be considered corrupt, but may be useful for diagnostics.