KLayout 0.29.8 (2024-10-28 63dd591e5) [master]
KLayout Documentation (Qt 5): Main Index » Various Topics » Connectivity
Connectivity
Use the connectivity page to specify the conductor layers and their connections.
On a conductor layer, all touching or overlapping shapes are connected.
A connection is made between conductor layer when the shapes of the two conductor layers overlap.
Optionally a via layer can be specified which must be present to make a connection between the two conductor layer.
To specify a conductor layer
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Use "layer/datatype" notation to specify explicit GDS layers and datatypes.
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Enter the layer name to specify either a named layer or a symbolic layer.
Symbolic layers must be defined in the symbol table (see Symbolic Connectivity Layers)
and can be computed from boolean expressions.
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Instead of using a symbolic layer,
enter a expression directly without defining a symbol (see Symbolic Connectivity Layers).
Inside the expressions
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Use "layer/datatype" notation to specify an original layer with explicit GDS layers and datatypes.
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Use the name to specify a named original layer or to refer to a different symbolic layer defined in a symbol entry.
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Use the operators '+', '*', '-' and '^' to specify logical OR, AND, NOT and XOR respectively.
The precedence of evaluation is '^' and '*' before '+' and '-'.
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Use round brackets to group expressions.
By creating conductor layers with boolean expressions, it is possible for example to separate an active area
layer of a CMOS transistor into source and drain regions by subtracting the gate poly. Symbolic layers are useful
to use "speaking" names for layers instead of the numeric layer/datatype specification.
Please note, that the net tracer is considerably slower when using boolean expressions.