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Representing Xic Cells in OpenAccess

When an Xic cell is saved in OpenAccess, up to three views may be created. The user has specified a library name where the views will be saved, and of course the cell name. Some write commands allow the user to save a cell under a different name.

If the cell contains physical data, this will be saved in a view named ``layout'' of OpenAccess view type ``maskLayout''. If the cell contains electrical data, the schematic will be saved in a view named ``schematic'' of view type ``schematic''. If a symbolic representation has been defined, this will be saved in a view named ``symbol'' of OpenAccess view type ``schematicSymbol''. This latter view can only exist, as part of an Xic cell representation, if a schematic view also exists. Reading or writing an Xic cell will involving translating each of these views that exist.

This group of properties applies to the OpenAccess interface.

stdvia property, number 7160
This property is applied to standard via sub-masters and instances, and is used by the translator to convert OpenAccess standard vias to Xic standard vias, and the reverse. The property is used in Xic to identify and specify standard via instances and sub-masters. The format of the property string is described in 5.8.1.

oa_cstmvia property, number 7161
This property is applied by the OpenAccess reader to master cells that represent a custom via. In Xic, vias are cells, they have no unique type as in OpenAccess. The string format consists of the cell identifier followed by parameter specifications. The cell identifier has the form
< libname> < cellname> < viewname>
This is followed by a space-separated parameter specification string in the same format as the pc_params property. A custom via master is basically a pcell sub-master.

When written back to OpenAccess, cells with this property will be ignored. A sub-master for the custom via will be created within OpenAccess when needed.

oa_orig property, number 7183
This property is used transiently when loading OpenAccess cell data into Xic. If is applied to cells, and removed when reading completes. If an instance is read before the corresponding cell definition, a dummy Xic cell descriptor is created and given this property. The property string contains the library and cell names, separated by a forward slash (`/') character. Using this information, the cell is read later.


next up previous contents index
Next: Python Support Up: OpenAccess Support Previous: OpenAccess Support   Contents   Index
Stephen R. Whiteley 2024-09-29