Technology File Layer Block Keywords: Conversion

The following keywords set the layer mapping for GDSII and OASIS format input and output. These can be programmed from within Xic with the Tech Parameter Editor in the Attributes Menu.

StreamData layernum datatype
This keyword is deprecated, and can be read but is not generated by Xic. The layernum and datatype are the layer mapping used when converting to and from GDSII format. The layer must be in the range 0 through 65535, and the datatype can take values -1 through 65535. Values larger than 255 are outside of the GDSII specification, but are sometimes used anyway although files containing such data may not be generally portable. If -1 is given as the datatype, all GDSII datatypes will be mapped to the present Xic layer, and datatype 0 will be used for output. Otherwise, the layer and datatype in a GDSII file must match those given for successful mapping to the Xic layer. Note that often the end of range values are reserved in other CAD environments, and that some releases of the GDSII format support only 64 layers and datatypes. The datatype is used by Xic only in conjunction with the NoDrcDatatype keyword, and is otherwise typically set to 0. This keyword has been superseded by StreamIn and StreamOut.

StreamIn layer_list [, datatype_list]
This keyword specifies a set of layer/datatype combinations that will map to the present Xic layer when reading GDSII and OASIS files. Any number of such lines can be present. The layer_list is a space-separated list of tokens, each of which is either a GDSII layer number (``32'') or a range of numbers (``35-41''). The datatype_list is similarly constructed, and is optional. The numbers in either list can range from 0 to 65535, though numbers larger than 255 are outside of the GDSII specification (but sometimes used anyway). If a datatype_list appears, it is separated from the layer_list with a comma. The line specifies that each of the datatypes listed on each of the GDSII layers listed will be converted to the present Xic layer. If the datatype list is absent, it defaults to ``0-65535''. For example,

StreamIn 5 7 8 21-30, 0 20-63

specifies that datatypes 0 and 20-63 on GDSII layers 5, 7, 8, and 21-30 will be mapped to the present Xic layer as a GDSII or OASIS file is read. Note that GDSII layers cam be mapped to more than one Xic layer. In this case, the geometry will be created on each of the Xic layers mapped to.

It is possible for more than one Xic layer to map from a given GDSII layer/datatype. If the MultiMapOk variable is set, then multiple objects will be created when a GDSII or OASIS file is read, one on each matching Xic layer. If this variable is not set, only the first mapping will be used, which will be the lowest matching layer found in the layer table.

StreamOut out_layer [out_datatype]
This line specifies a layer/datatype combination to be used when generating GDSII and OASIS files for the present Xic layer. One of these should appear for each Xic layer. The out_layer and out_datatype can be in the range 0-65535, though numbers larger than 255 are outside of the GDSII specification but are sometimes used anyway. Be aware that use of numbers larger than 255 may render the file non-portable. Note that often the end of range values are reserved in other CAD environments, and that some releases of the GDSII format support only 64 layers and datatypes. The default datatype, if not given, is 0.

If there are more than one StreamOut lines given for a layer, and the MultiMapOk variable is set, the objects will be added to the GDSII or OASIS file on each of the GDSII layers/datatypes specified. If the variable is not set, only the first StreamOut specification will be used.

There is no default for this keyword.

NoDrcDatatype datatype
If this keyword is given, then any object that has the given datatype will be ignored during DRC. On output, objects that have their DRC skip flags set will be written with this datatype, and not the default datatype given in the StreamOut line. The given datatype should appear in the input mapping for the layer.