next up previous contents index
Next: User-Specified Electrical Property Specifications Up: Property Specifications Previous: Property Specifications   Contents   Index

Physical Mode Property Specifications

This section lists the properties known to Xic that may be found in physical cells, instances, or objects. This lists only properties likely to be encountered by the user, there may be additional properties that are not specifically documented used internally by Xic. All physical properties known to Xic use numbers in the reserved range 7000 - 7199.

text property, number 7012
This property saves GDSII label parameters ANGLE, MAG, WIDTH, and PTYPE, which are unused by Xic. The string consists of a concatenation of keyword/value pairs, using the keywords above (not all need be present). These attributes will be reassigned to the label when a GDSII file is written.

pathtype property, number 7033
This property is used for physical mode wires of nonzero width which have a non-default path type. The string has the form
PATHTYPE pathtype
where pathtype is 0 for flush ends, 1 for rounded ends. The default pathtype is 2 (extended ends). This property is added to wires in native and CIF output if the CifOutExtensions variable has the wire extension flag set, and the wire extension new flag is not set. The wire end style is included in the wire specification in the present default syntax, so wire extension new is set by default.

grid property, number 7100
This property is applied to the top-level physical cell when the cell is saved, preserving the current grid setting. This property is used in physical mode only. The property string has the format
grid resol snap
where resol is the number of internal units per snap point, and snap is the number of snap points per grid line if positive, or grid lines per snap point if negative.

flags 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.

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

refcell property, number 7150
A reference cell is an empty cell with a refcell 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:

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

flatten property, number 7151
During extraction, simple cells that contain only geometry or perhaps all or part of a device can be logically flattened (see 16.4) 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.

nomerge property, number 7152
The nomerge property applies to physical boxes, polygons, and wires, and is used by the extraction system. 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.

stdvia property, number 7160
This property is given to standard via sub-masters and instances. The property is recognized by the OpenAccess plug-in providing transparent conversion between OpenAccess and Xic standard vias. The syntax is described in 5.8.1.

termorder property, number 7168
This is set to a space-separated list of group names, and can be applied to physical cells. It will provide the cell connection terminal names and ordering when electrical data are absent. The names must match net name labels (see 16.5) placed in the layout. Names not found are silently ignored.

skipdrc 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.

labelsize property, number 7180
This property is added to labels when writing to GDSII, and saves the label width, height and visibility status. The string has the format
width width height height [show|hide] [tlev] [liml]
where width and height are in internal units.

The keywords ``show'' or ``hide'' appended to the string store the display state of the label, which can be visible or ``hidden'', toggled by clicking with button 1 with the hift key held. The LabelHiddenMode variable controls the scope of this feature.

The tlev keyword gives the label the property of being invisible in instances of the containing cell, but visible when the cell is viewed as the top-level (current cell).

The liml keyword causes the label to limit the number of lines displayed, when the label text has multiple lines. The maximum line count defaults to 5, and is otherwise given with the LabelMaxLines variable.

The four flags are the same as those accessible with the XprpXform pseudo-property.

This group of properties applies to the OpenAccess interface.

oa_cstmvia property, number 7161
This property is applied by the translator to Xic cells that represent a custom via object from OpenAccess. The format is described in 2.11.

oa_orig property, number 7183
This property is applied transiently when reading cell data into Xic. The format is described in 2.11.

The following group of properties implements the Ciranova abutment protocol for parameterized cells. Parameterized cells may use this protocol to automatically merge abutted instances so as to share common features.

ab_class property, number 7185
This is similar to the Ciranova pycAbutClass property. The format of the ab_class property is described in 5.5.

ab_rules property, number 7186
This is similar to the Ciranova pycAbutRules property. The format of the ab_rules property is described in 5.5.

ab_directs property, number 7187
This is similar to the Ciranova pycAbutDirections property. The format of the ab_directs property is described in 5.5.

ab_shapename property, number 7188
This is similar to the Ciranova pycShapeName property. The format of the ab_shapename property is described in 5.5.

ab_pinsize property, number 7189
This is similar to the Ciranova pycPinSize property. The format of the ab_pinsize property is described in 5.5.

ab_inst property, number 7190
The format of the ab_inst property is described in 5.5.

ab_prior property, number 7191
The format of the ab_prior property is described in 5.5.

ab_copy property, number 7192 The format of the ab_copy property is described in 5.5.

The following property is required to implement the Ciranova protocol for stretch handles in parameterized cells. A stretch handle is a display element that can be dragged with the mouse, which initiates a change of a cell property and appropriate remastering.

grip property, number 7195
The format of the grip property is described in 5.4.

The remaining properties support parameterized cells (pcells). The super-master pcell contains a script reference, default parameter values, and (optionally) parameter constraint strings. When the super-master is instantiated, the script is executed producing a sub-master under a modified name, plus an instance of the sub-master. The instance contains the name of the super-master and a copy of the instantiation parameters.

pc_name property, number 7197
This property is assigned by Xic to pcell sub-masters and their instances. It provides the name of the pcell from which the sub-master or instance was derived.

pc_params property, number 7198
This property is assigned by the user to pcells, and contains the default parameter set. It will be assigned by Xic to sub-masters and instances, and contains the parameter set that was used to create the sub-master. See 5.1.3 for a complete description.

pc_script property, number 7199
This property is assigned by the user to a pcell, and appears only in the super-master. It contains the script, or a path to a script, which is executed when the pcell is instantiated. See 5.1.3 for a complete description.

next up previous contents index
Next: User-Specified Electrical Property Specifications Up: Property Specifications Previous: Property Specifications   Contents   Index
Stephen R. Whiteley 2022-05-28