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Parameterized Cells

The following !set variables affect parameterized cell (pcell) capabilities. Most of these track elements of the PCell Control panel obtained from the PCell Control button in the Edit Menu.

PCellAbutMode
Value: integer 0-2, default 1.
Xic provides an internal implementation of the Ciranova auto-abutment protocol (see 5.5). This variable sets the value of the otherPinsOnNet parameter mentioned in the protocol description. How the pcell uses this variable is up to the pcell author, there is really no a-priori interpretation, it is an integer of value 0, 1, or 2.

The Ciranova Nmos2 example pcell interprets the value to have the following meanings. This is likely to be used in other pcells as well.

0 Auto-abutment is disabled.
1 Abutment takes place with no contact between the gates.
2 Abutment takes place with a M1 contact between the gates.

This variable tracks the Auto-abutment mode selection menu in the PCell Control panel.

PCellHideGrips
Value: boolean.
Xic implements the Ciranova stretch handle protocol (see 5.4), and by default stretch handles are visible in selected, expanded cell instances, and when editing the sub-master. If this variable is set, all stretch handles will be invisible and disabled.

This variable tracks the state of the Hide and disable stretch handles check box in the PCell Control panel.

PCellGripInstSize
Value: integer 0-1000.
Stretch handles are not shown and inactive if the instance rendering size is too small. This is to avoid triggering a stretch inadvertently. By default, the smallest of the instance height/width must be 100 screen pixels or larger to show and activate stretch handles. This variable can be set to provide a different threshold.

This variable tracks the value of the Instance min. pixel size for stretch handles entry in the PCell Control panel from the Edit Menu.

PCellKeepSubMasters
Value: boolean.
When a parameterized cell (pcell) is instantiated, a sub-master cell is created in memory which represents the instantiation for its given parameter set. By default, sub-master cells exist only in memory, and are created as needed from the original pcell.

When this variable is set, sub-masters that have been created will be included when writing output. This will also be true when the StripForExport variable is set. This applies when writing all output, except when using the Save and Save As buttons in the File Menu, and the equivalent text accelerators and including the prompts when exiting the program. It is also ignored when using the Save script function.

When opening a layout containing pcell instances and the corresponding cell files are found, the cell files will be read instead of evaluating the pcell. This can be faster, and it also allows the design to be opened if the original pcell is not available or can't be processed. However, the cells will behave like normal cells, not pcells, in this case.

This variable tracks the state of the Include parameterized cell sub-masters check box in the Export Control panel.

PCellListSubMasters
Value: boolean.
When a parameterized cell (pcell) is instantiated, a sub-master cell is created in memory which represents the instantiation for its given parameter set. By default, sub-master cells exist only in memory, and are created as needed from the original pcell.

When this variable is set, sub-masters that have been created will be included in the list of modified cells contained in the Modified Cells pop-up, which is obtained from the Save button in the File Menu. The sub-masters can be saved as native cell files in the current directory.

When opening a layout containing pcell instances and the corresponding cell files are found, the cell files will be read instead of evaluating the pcell. This can be faster, and it also allows the design to be opened if the original pcell is not available or can't be processed. However, the cells will behave like normal cells, not pcells, in this case.

This variable tracks the state of the List sub-masters as modified cells check box in the PCell Control panel.

PCellScriptPath
Value: string.
This variable provides a search path (see 2.6) to use when locating parameterized cell (pcell) scripts. This applies when a pcell pc_script property uses the @READ directive to obtain the corresponding script, and the path provided by the directive is not rooted.

Unlike the main search path variables described in E.3, this variable is unset by default.

PCellShowAllWarnings
Value: boolean.
During pcell script evaluation, certain warning messages are disabled, including checking for coincident objects. Some of the Ciranova example pcells produce such warnings, and it is highly annoying that the messages pop up after every evaluation. The warnings may be of interest to the pcell author, but are generally nothing but a nuisance to the pcell user. If this variable is set, then these warnings will be displayed and not suppressed.

This variable tracks the state of the Show all evaluation warnings check box in the PCell Control panel.


next up previous contents index
Next: Standard Vias Up: Xic Variables Previous: OpenAccess Interface   Contents   Index
Stephen R. Whiteley 2017-04-09