Note: $cdk_dir == toplevel directory of NCSU CDK
The CDK supports reading and writing of mask data in CIF and GDSII (Stream) formats.
When creating or reading mask data the CDK generally uses a ``layer map'' to define the correspondence between mask layers and Cadence layers. The code in $cdk_dir/skill/menus/ciw/setPIPOform.il automatically writes the name of the layer map file in the PIPO (Physical In, Physical Out) form based on the values of the global variables NCSU_cifInLayermapFile, NCSU_cifOutLayermapFile and NCSU_streamInLayermapFile. These variables are strings containing the complete path to the layer map file the user wishes to use for CIF input, CIF output, and GDSII (Stream) input respectively. They are set to $cdk_dir/pipo/cifInLayermap, $cdk_dir/pipo/cifOutLayermap, and $cdk_dir/pipo/streamInLayermap by default. (Layer translation for GDSII output is defined in the technology file $cdk_dir/techfile/layerRules.tf, so a layer map file is not needed for this function.)
The CDK includes a list of all the MOSIS SCMOS layers and their corresponding GDSII numbers and CIF layer abbreviations.