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GDSII Layer Mapping Dialog Box
GDSII Translator in the Project Editor
The Layer Mapping dialog box allows you to map the GDSII streams to the Sonnet project levels on import and map Sonnet project levels to GDSII streams on export. The settings in this dialog box are also used to automatically create Technology Layers during the import or map Technology Layers to GDSII streams when exporting the Sonnet project to a GDSII file. Please see the appropriate section below for more information on the functions of the controls.
When you import a GDSII file, the translator reads the layer information from the GDSII file, then opens this dialog box with the stream information displayed. You edit the dialog box to provide the correct mapping of the GDSII file to the Sonnet project.
The various fields are described below. The first two columns refer to the incoming GDSII file. The last four columns are the choices to be used in the Sonnet project editor for the GDSII elements identified in the first two columns.
GDSII Stream: The layer number as defined in your circuit layout program. Note that the layer number has no relationship to the project editor’s metalization level number.
GDSII Data Type: The data type number as defined in your circuit layout program. Each layer, defined by your circuit layout program, may have multiple data types.
Map: Use this checkbox to select which layers in the GDSII file you wish to map to the Sonnet project. If this checkbox is off, the GDSII stream layer is not mapped to the Sonnet project. If the checkbox is on, then the GDSII stream layer and data type in the first two columns are mapped to a Technology Layer, object, level and material type specified in the last four columns. If you wish to map all the layers, select the checkbox at the top of the column under the rightward pointing arrow. Clearing this checkbox deselects all layers from mapping.
Tech Layer: Enter a name to identify the Technology Layer which is created in the resulting Sonnet project when your circuit is translated. If you do not wish to create a Technology Layer for the stream, select "None" from the drop list. A default name is automatically entered by the software but you may edit the entry and enter a custom name if you desire. The type, level and material used by the Tech Layer are determined by the selections made in the Object Type, Level and Material columns.
If you are importing to a project that contains Technology Layers, the Technology Layers fields are filled in by default, based on the properties of the Tech Layer. For any row which is set to a pre-existing Tech Layer, the Project Editor fields (Object type, Level, and Material) will be fixed to the values set by the corresponding Tech Layer, and may not be changed.
Object Type: This drop list allows you to select what type of object should be created in the Sonnet project. Select Metal for planar metal polygons, Brick for dielectric bricks or Via for via polygons from the drop list. You select or enter the metal type or brick material from the Material drop list. If a Technology Layer is being created, this selection also determines the Technology Layer type: Metal, Brick or Via.
Level: This specifies the level in the Sonnet project where you wish to place the stream layer and data type being input from the GDSII file. If a Technology Layer is being created, it is assigned to this level. The top level is number 0. For via conversion, you input a range of levels. For example, a via which extends from level 2 upwards to level 0 would be 2-0. A via extending from level 3 to ground would be 3-GND. Note that the project editor creates enough metal levels in the destination project to accommodate any levels entered in this field. For example, if a via level of 2-6 is input, the project will have at least 8 levels (0-GND).
Material: Select the material type you wish to use for the objects being translated. The choices available depend on what type of object is selected in Object type: Metal, Via, or Brick and what materials are available in the template project, if one is being used. You may also edit this entry with a new material name, whose parameters you can later input in the project editor. If a Technology Layer is being created, this is the Material used for the Technology Layer.
For example, if you are importing a GDSII file into a project with four defined types of planar metal, you may choose from those four planar metal types for any metal polygons being translated into the Sonnet project.
Add: Click on this button to add another entry row. Additional rows allow you to map a single GDSII stream to multiple Technology Layers, object types, levels, and/or materials.
Delete: Click on this button to delete the presently selected row in the dialog box.
Load: Click on this button to load the settings from an existing layer file with mapping settings for the GDSII file you are importing.
Save: Once the mapping is specified, you may wish to save the settings for subsequent imports of similar GDSII files. Click on the Save button to save your settings in a file. It is recommended that you use a ''.lay'' extension which is the default.
Next: Click on the Next button to continue the import GDSII process. The GDSII translator opens the Import Status dialog box to import your GDSII file.
When you export a GDSII file, you use the Layer Mapping dialog box to map the objects in your Sonnet project to the GDSII streams which will be created in the output file. The translator reads your project file and gathers information about the metal levels, objects, materials and Technology Layers, then opens this dialog box, with an initial mapping displayed based on your export options. You may then edit this mapping if you wish. Note that entries are not created for levels in the Sonnet project which contain no objects.
The various fields are described below. The first two columns refer to the GDSII streams created in the exported GDSII file. The last four columns are the inputs from the Sonnet project which are used to create the GDSII streams identified in the first two columns.
GDSII Stream: If the Sonnet Level was assigned to a Technology Layer, then the GDSII Stream number entered in the Technology Layers dialog box is used as the default number to identify the stream. If there is no Technology Layer, then the default value is the Sonnet metal level. If you wish to use another stream number, enter the desired value. This must be an integer value. Note that aside from the default, the layer number has no relationship to the project editor’s metalization level number.
GDSII Data Type: The data type number as defined in your circuit layout program should be entered here. Each GDSII stream may have multiple data types. The data type should be assigned based on the type of Sonnet object and materials being translated using the settings in this row.
Map: Use this checkbox to select which levels in the Sonnet project you wish to map to the GDSII file. If this checkbox is off, the Sonnet level is not translated to the GDSII output file. If the checkbox is on, then the objects identified by the settings in the last four columns are translated to the corresponding GDSII stream and data type. If you wish to map all the layers, select the checkbox at the top of the column under the leftward pointing arrow. Clearing this checkbox deselects all layers from mapping.
Tech Layer: This name identifies the Technology Layer which will be exported to the GDSII stream elements. You may select any existing Technology Layer from the drop list. If a Technology Layer is selected, then the Object Type, Level and Material settings are inherited from the Technology Layer and may not be changed.
Object Type: This drop list is only enabled if a Technology Layer is not selected to export to this GDSII stream. This drop list allows you to select what type of object should be output from this metal level. Select Metal for planar metal polygons, Brick for dielectric bricks or Via for via polygons. If a Technology Layer is selected, this identifies the type of Technology Layer: Metal, Brick or Via.
Level: This drop list is only enabled if a Technology Layer is not selected to export to this GDSII stream. This specifies the level in the Sonnet project from which you are exporting to the identified GDSII stream. The top level is number 0. For via conversion, you input a range of levels. For example, a via which extends from level 2 upwards to level 0 would be 2-0. A via extending from level 3 to ground would be 3-GND.
Material: This drop list is only enabled if a Technology Layer is not selected to export to this GDSII stream. Select the material type you wish to use for the objects being translated. The choices available depend on what type of object is selected in Object type: Metal, Via, or Brick and what materials are defined in the project. The default setting is Any which causes any polygon of the correct object type, regardless of the material, to be included in the output stream. If you select a specific material, then only polygons using that material are included in the output stream. All materials defined for the Object Type selected appear in the drop list. In other words, if the Object type is Metal, then all planar metals defined in your project appear in the list and may be selected. If a Technology Layer is selected, the Material used by the Technology Layer is displayed here.
Add: Click on this button to add another entry row. Additional rows allow you to map a Technology Layer or Sonnet Level to multiple GDSII streams or data types.
Delete: Click on this button to delete the presently selected row in the dialog box.
Save: Once the mapping is specified, you may wish to save the settings for subsequent exports of similar GDSII files. Click on the Save button to save your settings in a file. It is recommended that you use a ''.lay'' extension which is the default.
Load: Click on this button to load the settings from an existing layer file with mapping settings for the GDSII file you are exporting,
Next: Click on the Next button to continue the export GDSII process. The GDSII translator opens a browse window which allows you to enter the filename for your exported GDSII file.