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Physical Mode Properties

There are a few properties that may be applied to physical cells or objects in support of certain Xic features.

Flags Property: Property number 7105
This property can be be applied to physical cells. The property string can take one of two forms: a hex number, or a space-separated list of string tokens. The tokens and corresponding bits are

Bit Keyword Description
    When set, the cell is ``opaque'' with regard to
0 OPAQUE extraction. The cell will look like a black box
    with terminals.
1 CONNECTOR Not implemented, don't use.
2 USER0 User flags, not used by Xic. These flags may be
3 USER1 useful to the user.

This property can be set in physical mode with the Cell Property Editor.

When the ExtractOpaque variable is set, the OPAQUE flag is ignored.

Reference Cell Property: Property number 7150
A reference cell is an empty cell with a Reference Cell property, which references a cell hierarchy in another layout file. Reference cells can exist in memory or as a native cell file on disk.

The string for this property consists of space-separated keyword=value pairs. The known keywords are as follows:

cellname
The top-level cell to extract from the referenced hierarchy.
dbname
The CHD name in memory. This is never written to a file, it is only used when the cell is in memory.
filename
The full path to the referenced layout file.
bound
The bounding box, may be used for area filtering, in the form L,B,R,T where the values are floating-point in microns.
aflags
Alias flags integer, these set name aliasing modes.
aprefix
Cell name change prefix.
asuffix
Cell name change suffix.

Flatten Property: Property number 7151
During extraction, simple cells that contain only geometry or perhaps all or part of a device can be logically flattened into their parent cells for extraction purposes. If this property is set in a cell, that cell will always be considered as part of its containing cell by the extraction system.

This is identical to the effect of listing the cell name in the FlattenPrefix variable.

The string for this property is ignored, but is set to ``flatten'' by convention. The property can be applied by the user with the Cell Property Editor.

NoMerge Property: Property number 7152
The NoMerge property can be applied to physical boxes, polygons, and wires with the Property Editor. If this property is found on any object used to recognize a device body, that device will never be merged with similar devices. This is relevant when merging is enabled for the device during extraction, and one wants to suppress this in individual cases. It prevents both parallel and series merging.

Skip DRC Property: Property number 7178
This property is applied in output to boxes, polygons, or wires which have the skip DRC flag set. It is used to set the skip DRC flag in boxes, polygons, and wires as an input file is being read.

The remaining properties support template cells.

Template Name Property: Property number 7197
This property is assigned by Xic to cells and instances derived from template cells. It provides the name of the template cell from which the current cell was derived.

Template Params Property: Property number 7198
This property is assigned by the user to template cells. It contains a list of parameter assignments to provide default values to the template cell. Instances and masters obtained from the template will also contain this property, assigned by Xic, containing the actual parameter values used for instantiation.

Template Script Property: Property number 7199
This property is assigned by the user to template cells. It contains the script which is executed when the template cell is instantiated.


next up previous contents index
Next: Device Properties Set By Up: Property Specifications Previous: Special Properties   Contents   Index
Stephen R. Whiteley 2012-04-01