General

Defines the scope of the options settings you make in the form, and loads and saves the settings from and to an options file.

Display

Specifies how the Layout XL windows are arranged on your desktop, how draglines are displayed in the layout window, and to enable and disable cross-selection and net probing.

Connectivity

Sets the Layout XL connectivity extraction parameters for the current design.

Generation

Specifies how certain components are handled when they are generated in the layout view.

Parameters

Specifies which parameters are to be ignored by the generation and check command and how parameters are compared during Check Against Source.

Configure

Lets you view the presets that reflect the current state of the associated environment variables in the .cdsenv file, or the state of the associated form fields.

Scope

This section lets you specify whether the option settings apply for the current cellview only or globally for the current cellview and all the cellviews opened subsequently in Layout XL.

Global

Applies the settings to the current cellview and to all cellviews opened subsequently in Layout XL.

Cellview

Applies the settings only to the current cellview. Choosing this option grays out the Connectivity, Generation, and Parameters tabs, along with certain options on the Display and General tabs.

Load/Save

This section lets you load, save or delete values to or from a cellview, library, technology library, or options file.

Cellview

Updates the options for the cellview from which you opened the form.

Library

Updates the library that contains the cellview from which you opened the form.

Tech library

Updates the technology library of the cellview from which you opened the form.

File

Updates the.cdsenv file (the default) or another file specified in the text field.

Constraint-Aware Editing

This section provides options for constraint-aware editing.

Constraint-aware editing

Ensures that the Copy, Move, Stretch, and Rotate commands honor the following constraints: Alignment, Fixed, Locked, Matched Parameters, Orientation, Matched Orientation, and Symmetry.

This is a system-wide setting that applies to all existing and new windows opened in the current Virtuoso session.

See Constraint-Aware Editing.

Environment variable: constraintAwareEditing

Connectivity Reference

This section specifies the connectivity reference for the schematic window.

Open with

Specifies whether the Virtuoso Schematic Editor is launched when you launch Layout XL or a higher tier and, if the schematic editor is started, which of its tiers opens. You can choose from: Schematic L, Schematic XL, No Schematic.

No Schematic implies that the Virtuoso Schematic Editor is not launched. The default is Schematic XL.

Environment variable: lxSchematicDefaultApp

The schematic editor tier level does not change when you launch Layout XL from the Virtuoso Schematic Editor XL nor when you switch between layout editor tier levels after Layout XL or GXL has been launched. If you choose No Schematic, the Open connectivity reference during Edit In Place/Descend field is disabled.

Open connectivity reference during Edit In Place/Descend

Specifies whether the source cellview is opened when you use the Edit In Place or Descend commands. When switched off, the layout cellview remains open in Virtuoso Layout XL mode, but with no connectivity reference.

The field is disabled if you choose No Schematic for the connectivity reference to Open with.

If you choose to open the connectivity reference, you can choose to open the schematic cellview in a new window or a new tab. By default, the schematic cellview opens in a new window.

Environment variables: openConnRef, openConnRefTab

Close schematic when exiting layout

Closes the schematic window associated with the layout window that is closed, if the layout was opened first in Virtuoso Layout XL or a higher and the schematic window was automatically opened.

If the schematic was opened first and then a Virtuoso Layout XL or higher window was launched from the schematic, the schematic window is not automatically closed when the layout window is closed.

Environment variable: closeSchWindow

Power/Ground Nets

This section provides options to specify the list of power and ground net names.

Power net names

Specifies the list of power net names used to achieve optimized chaining results in Layout XL device level schematics.

Environment variable: lxSupplyNetNames

Ground net names

Specifies the list of ground net names to help you achieve optimized chaining results in Layout XL device-level schematics.

Both lists are also used by the Virtuoso Custom Digital placer to exclude power and ground nets during wire length optimization; and to determine the power nets that are hidden when the hideDraglinesForGlobalNets environment variable is switched on.

Initial Display - Auto arrange windows

Controls whether Layout XL automatically rearranges its four windows on your desktop when you launch the application.

The default is on, meaning that the windows are positioned based on the values specified for the following environment variables: ciwWindow, lamReadFileMessage, lxAllowPseudoParallelNets, and schematicWindow.

If those environment variables are not set, or they are set to the default value "((0.0 0.0) (0.0 0.0))", Layout XL tiles the three windows based on the height and width of your screen. This option is not available in Cellview mode.

See General tab.

Environment variable: autoArrange

Draglines - Display Draglines

Toggles the display of draglines when using the Generate Selected From Source, Generate Clones, Move, and Stretch commands. If the option is OFF, the options in this section are disabled.

By default, the Display Draglines option is ON.

Environment variable: flightLineEnable

The option is not available in the Cellview mode.

See General tab.

Show distant connections

Displays draglines for all the connections to the instance that is being manipulated. When switched OFF, draglines are shown only for the connections closest to the current instance.

Environment variable: showDraglinesForDistantConns

Hide global, power, and ground nets

Hides draglines for global nets and power and ground nets specified using the lxGroundNetNames and lxSupplyNetNames environment variables.

See hideDraglinesForGlobalNets.

Use colors

Shows each dragline in a different color.

Displaying many draglines during interactive commands can impair the performance of Layout XL. To mitigate these effects, use the maxDragFig environment variable to limit the number of figures that can be in a dragset.

To set maxDragFig interactively so that it takes effect in the current session, type the following in the CIW, where win is the window to which the limit applies.

win~>maxDragFig = 1000

To set a default value for maxDragFig, which will be used in all future Layout XL sessions, add the following line in your .cdsenv file.

graphic maxDragFig int 1000 nil

Environment variable: colorDraglines

Cross-selection

Enables cross-selection of components between schematic and layout. When you select a component in the layout, the corresponding component is selected in the schematic and vice versa, unless the instance is ignored in either view.

Environment variable: crossSelect

Connectivity - Probe nets during object creation

Controls whether nets that are tapped during interactive editing are highlighted in the layout canvas.

Environment variable: probeDuringCreate

Messages - Redirect Layout XL messages to separate Info window

Shows the messages issued by the Check Against Source, Update Layout Parameters, and Update Schematic Parameters commands in a separate info window instead of in the CIW.

Environment variable: infoWindow

Controls

Specifies the verification controls for the layers in the design ans the connectivity assignment of the shapes and instance pins.

Annotations

Sets annotation types for incomplete nets, illegal connections, and necessary connections.

Limits

Specifies annotation limit values.

Verification Controls

This section specifies the verification controls for the layers in the design.

Derive extractable layers from constraint group

Sets the default constraint group from which Layout XL derives the extractable layers in the design.

See Prerequisites for Using the Layout XL Connectivity Extractor.

Diagnostics Report

Displays extraction-related information about the selected constraint group and appropriate warning messages to indicate if the technology file has been correctly set up for extraction. You can display the report in a separate information window or in the CIW.

See Extractor Diagnostics Options Form

Extract connectivity to level

Specifies how much of the design hierarchy the extractor considers when extracting the top-level design.

See Extracting a Top-Level Design.

Whatever value you set for Extract connectivity to level, the extractor only extracts the top level; i.e., it only changes the connectivity of objects or creates markers at the top level of the design. To extract hierarchical cellviews, set the value of this option to a value greater than 0 and use the Extract Layout command.

Update connectivity information when design is modified

Enables incremental connectivity extraction, which updates the connectivity model whenever the design is modified. When switched off, the connectivity model is not updated automatically and no new short or open violation markers are generated in the layout window. Even when incremental extraction is switched off, you can run connectivity extraction at any time using the Connectivity – Update – Extract Layout command.

Environment variable: extractEnabled

Enable substrate connections and set well layers as soft

Allows connections to the substrate and sets the well layer connections as soft connections in the current cellview.

Use (identifier) to define nets as virtually connected

Indicates the identifier that when placed after the net name in the label text means that the corresponding set of physically connected shapes are virtually-connected. By default, colon (:) is used as a virtual-connect identifier. The connectivity extractor does not report open markers between virtually connected shapes. However, after extraction, an INFO message is issued in the CIW, which indicates the number of virtual connections.

Environment variables: extractEnableVirtualConnections, extractVirtualConnectionSeparator

If virtual connections are enabled, a colon (:) at the end of a terminal name is not considered as a name mismatch.

See Enabling Virtual Connections.

Extract through pcells

Specifies that the connectivity of non-pin shapes in Pcells is extracted.

Check shorted terminals in pcells

Checks and prevents incorrect shorts due to incorrectly assigned shapes in Pcells.

By default, the option is deselected.

This option is available only if Extract through pcells is selected.

Stop Layers

This section specifies the controls on stop layers during extraction.

Promote all stop shapes

Specifies whether stop shapes at the extractStopLevel + 1 level are visible to the extractor.

Environment variable: extractPromoteAllStopShapes

Ignore color lock state

Specifies whether lock state of shapes should be ignored during extraction.

Environment variable: extractIgnoreColorLockState

Connectivity Assignment

This section specifies the connectivity assignment of the shapes and instance pins.

Keep shape assignment

Preserves the connectivity of a design by keeping the shapes assigned. By default, the option is deselected.

Environment variable: extractKeepShapeAssignment

Remove lxStickyNet property on non-floating shapes

Ensures that shapes that are connected to a connectivity source, such as a pin, an instance terminal, or a label, automatically have their lxStickyNet Property property removed to avoid any shorts or illegal must connections. By default, the option is OFF.

Environment variable: extractRemoveStickyProperty

During a Copy or Repeat Copy run with Copy Connectivity selected, the option automatically removes the lxStickyNet Property property on floating sticky shapes to avoid any shorts or illegal must ‘connections.

The lxStickyNet Property property on a shape is not removed if the sticky shape is created by a router.

The sticky shape and the pin are on the same net.

The sticky shape is stopped by another layer.

Connect unassigned instance pins

Ensures that an instance pin is automatically connected to the net assigned to the overlapping shape. By default, the option is ON.

For example, consider an unassigned instance terminal that overlaps a shape connected to a net. If the option is ON, the instance terminal is assigned to the net. If the option is OFF, an illegal connection marker is created in the Annotation Browser and the instance terminal stays unassigned.

Environment variable: extractConnectUnassignedInstTerms

Assign shapes from attached labels

Ensures that a top-level shape with an attached label is automatically connected to the net referenced by the label text. By default, the option is OFF.

See Connectivity from Attached Labels to Consider During Extraction.

Assign shapes from overlapping labels as defined by ‘stampLabelLayers’ rule

Ensures that a shape overlapping the origin of a label is assigned to the net referenced by the label text. By default, the option is OFF.

See Connectivity from stampLabels During Extraction.

Incomplete nets (opens)

Reports open violations in the design. When switched OFF, none of the dependent options is honored by Layout XL.

Environment variable: extractVerifyOpenViolations

• Unimplemented instance pins: Reports violations to indicate that the extractor should consider instance terminals with pin shapes that are not extractable (including instance terminals with no pin shapes at all).
• Shapes on non-routing layers: Controls if open markers should be created with instance pin figures on a non-routing layers.
• Signal types: Specifies the signal types in the design for which open markers should be reported. To report open markers for all the signals, click the All button. To specify that none of the signals be reported for open or incomplete nets, click the None button.

Incomplete must Connect All Pins

Reports the open net connections for pins that have the mustJoinAllPins property set.

Illegal weak connections

Reports the weak-connect violation markers for the current cellview in Annotation Browser.

Environment variable: extractVerifyWeakMarkers

Illegal must connections

Reports the must-connect violation markers for the current cellview in Annotation Browser.

Environment variable: extractVerifyMustConnectMarkers

Illegal hierarchical connection violations

Reports the illegal hierarchical connections in the current cellview.

Environment variable: extractVerifyIllegalHierConnections

Ignore unassigned hierarchical shapes

Ignores the unassigned hierarchical shapes when checking illegal hierarchical connections.

Environment variable: extractVerifyIllegalHierConnectionsIgnoreUnassignedHierShapes

Illegal overlaps for stopped colored shapes

Reports illegal overlap violations for color-dependent stopping of shapes. By default this option is deselected. See Support for Color-Dependent Shape Trimming.

Environment variable: extractVerifyIllegalOverlapsForStoppedColoredShapes

Unnecessary pseudo-parallel connections

Reports the overlap between two sub-nets of a pseudo-parallel net.

Environment variable: extractVerifyUnnecessaryPseudoParallelConnections

Maximum number of opens

Specifies the highest number of open violation markers that can be generated by the extractor for a particular net or cellview. By default, the extractor can generate a maximum of 100 open violation markers per net and 5000 open violation markers per cellview.

Environment variables: extractCellviewOpenViolationLimit,

extractNetOpenViolationLimit

Maximum number of shorts

Specifies the highest number of short violation markers that can be generated by the extractor for a particular net or cellview. By default, the extractor can generate a maximum of 100 short violation markers per net and 1000 short violation markers per cellview.

Environment variables: extractCellviewShortViolationLimit, extractNetShortViolationLimit

Maximum number of illegal connections

Specifies the highest number of illegal connections that can be reported by the extractor for a particular design. By default, the extractor can report a maximum of 1000 illegal connections per design.

Environment variable: extractCellviewIllegalConnectionLimit

Maximum number of unnecessary pseudo-parallel connections

Specifies the highest number of unnecessary pseudo-parallel connections that can be reported by the extractor for a particular cellview. By default, the extractor can report a maximum of 1000 such connections per cellview.

Environment variable: extractCellviewUnnecessaryPseudoParallelConnectionLimit

Maximum number of invalid connections

Specifies the highest number of invalid connection markers that can be generated by the extractor for a particular net or cellview. By default, the extractor can generate a maximum of 100 invalid connection markers per net and 1000 invalid connection markers per cellview. (Virtuoso MultiTech Framework)

Generation

This section lets you specify the options available in Generation section.

Split mfactored devices

Controls whether Layout XL places schematic devices with the mfactor Property property as multiple devices in the layout.

See Splitting Mfactored Devices.

Environment variable: mfactorSplit

Split sfactored devices

Controls whether Layout XL places schematic devices with the sfactor Property property as multiple devices in the layout.

See Splitting Sfactored Devices.

Environment variable: sfactorSplitsfactorSplit

Split fingered devices

Controls whether each finger of a schematic device will be placed in the layout as a separate device.

See Splitting Fingered Devices.

Environment variable: fingerSplit

Create pseudoparallel connections

Enables the detection of pseudoparallel nets during chaining. A pseudoparallel net connects nodes that are always the same voltage, so the current does not pass through the net.

See Generating a Layout without Chaining and Folding on Pseudoparallel Nets and Defining a Pseudoparallel Connection.

Environment variable: setPPConn

Create implicit bus terminals

Creates, checks, and updates implicit bus terminals in the layout cellview based on the explicit bus terminals in the schematic cellview. This avoids the need to run verilogAnnotate on the layout cellview before referencing the cellview for:

• Running verilog2oa
• Importing another verilog design into Cadence Innovus Digital Implementation System.

The Create implicit bus terminals option is OFF by default.

Environment variable: createImplicitBusTerminals

Device orientation

Controls the orientation of Layout XL layout devices generated from the schematic. Devices generated with a particular orientation may be further transformed if either the Chain, Fold, or Chain Folds options are switched on.

Environment variable: lxGenerationOrientation

PR boundary snap

Controls the snapping of the PR boundary and the area boundaries when running the Generate All From Source or the Adjust Boundary command.

• None implies no boundary snapping takes place.
• Lower Left creates the PR boundary of the specified size and snaps the lower-left point of the boundary bbox to the grid.
• All Points snaps all the points of the PR boundary bbox to the grid. This may result in the boundary bbox being larger than expected.

Environment variable: prBoundarySnap

Auto Adjustment

This section lets you specify the auto adjustment options.

Abut devices

Turns on automatic abutment, which abuts prepared devices so that they can share pins. Abutment is switched on for both automatic and interactive layout generation and during automatic placement using the Virtuoso Custom Digital Placer.

Environment variable: autoAbutment

• Align abutted devices snaps an instance in the direction perpendicular to the direction of abutment in order to align the instances
• Preserve terminal contacts specifies whether pin properties are preserved when an instance is abutted. Switching this option on means that the terminal contacts will be preserved when you abut devices in Layout XL.
  Environment variable: preserveTerminalContacts
• Perform auto abutment only after a move or stretch restricts abutment to occur only after interactive edits using the Move and Stretch commands.

Space components

Turns on automatic spacing, which allows components with the properties vxlInstSpacingDir Property and vxlInstSpacingRule Property to be spaced automatically according to the values specified in the properties.

If one of the devices is in any type of group (including a synchronous clone), the other device must be in the same group for automatic spacing to occur.

Environment variable: autoSpace

Permute pins

Turns on automatic pin permutation during manual routing or editing.

See permuteRule Property.

Mirror devices

Specifies that if a short violation is created during abutment, then Layout XL first mirrors the device to resolve the short. If this is unsuccessful, Layout XL attempts to resolve the short by permuting the pins. If you switch the option off, Layout XL uses only pin permutation when attempting to resolve shorts.

If one of the devices is in any type of group (including a synchronous clone), the other device must be in the same group for automatic mirroring to occur.

Environment variable: autoMirror

Process all violations during batch extraction

Specifies if the XL fixer engines, such as auto-permute, auto-mirror, auto-spacing, and auto-abutment, should process the violations during batch extraction.

Environment variable: processBatchViolations

Device Folding

This section lets you specify the device folding options.

Generate minimal folding

Creates the minimum number of folded devices. When switched off, Layout XL generates an odd number of folded devices. For example, it adds one fold if the device width divided by number of folds yields an even number.

Environment variable: lxStackMinimalFolding

Retain device orientation

Preserves the original device orientation when running the Generate Folded Devices command or the Generate All From Source command with the Fold option switched on.

If the Chain option is also switched on, device orientation is not preserved.

Environment variable: lxRetainFoldOrient

Update width parameter method

Specifies how the Update Layout Parameters command updates folded devices when the width value is changed in the schematic.

• No Change: Does not update folded devices.
• Equalize: Creates folds of equal widths in the layout instance. The number of folds does not change, only (potentially) the width of each fold changes.
  For example, the total width in the schematic is 12 and is distributed as follows in the layout.

  layout widths I1.1 w = 2
                I1.2 w = 4
                I1.3 w = 6
   

  If you change the width in the schematic to 15 and run Update – Layout Parameters with this option set, the new widths are as follows.

  layout widths I1.1 w = 5
                I1.2 w = 5
                I1.3 w = 5
   

• Distribute: Distributes the additional (or reduced) width equally amongst all the folds in the layout instance. Again, the number of folds does not change, only the width of each fold changes.
  For example, the total width in the schematic is 12 and is distributed as follows in the layout.

  layout widths I1.1 w = 2
                I1.2 w = 4
                I1.3 w = 6
   

  If you change the width in the schematic to 18 and run Update – Layout Parameters with this option set, the new widths are as follows.

  layout widths I1.1 w = 4
                I1.2 w = 6
                I1.3 w = 8
   

  An extra 2 units of width is added to each layout instance.

The Update Layout Parameters command applies lxRounding on the folded widths before setting to maintain the widths as rounded during folding. The Check Against Source command will continue to report the total width, which may not match in this case.

Environment variable: lxUpdateFoldedWidth

Device Chaining

This section lets you specify the device chaining options.

Create interdigitated chains

Automatically identifies nodes that qualify as pseudoparallel connections and defines them during chaining and abutment. A pseudoparallel net connects nodes that are always the same voltage, so the current does not pass through the net. Contacts are dropped automatically, if appropriate. However, if the Preserve terminal contacts option is switched on, the contacts are preserved.

This option applies only when chaining is turned on. It does not control the automatic identification and creation of pseudoparallel nets during manual abutment. To do that, switch on Create pseudoparallel connections.

Environment variable: lxAllowPseudoParallelNets

Maximum number of devices in a chain

Sets the maximum number of devices permitted in a chain.

Search levels up for abutments

Controls how far up the hierarchy Layout XL looks for opportunities to chain devices. A value of 0 means that chaining can look only in the same hierarchical level. A value of N means that chaining can look up N levels of hierarchy.

This option is always considered by the Generate All From Source and Generate Selected From Source commands. However, the Generate Chained Devices command considers it only if there are 100 instances or more in the selected set.

Environment variable: lxStackPartitionParameters

Align P Devices

Controls the alignment of p-device chains. The default alignment for p-device chains is “Top” but you can choose to align a chain to “Bottom” or “Center”.

Environment variable: lxChainAlignPMOS

Align N Devices

Controls the alignment of n-device chains. The default alignment for n-device chains is “Bottom” but you can choose to align a chain to “Top” or “Center”.

Environment variable: lxChainAlignNMOS

Chain left net

Controls whether source or drain nets are optimized to the left of the generated chains. The default is Source, which means a chain is optimized so that one of its source nets is on the left-hand side (where possible). Set to Either if you have no preference (and to maintain the default behavior from previous releases).

Source and Drain here refer to schematic source and drain nets, and not the layout source and drain nets, which may have been permuted.

Environment variable: chainLeftNet

Chain effort

Controls the effort applied during chaining. Increased effort can improve the quality of results, but it can be time-consuming.

The default is Nominal.

Environment variable: chainEffort

Chain optimize

Optimizes the chains by minimizing the number tracks or maximizing the number abutments or both.

The default value is Both.

Environment variable: chainOptimize

Ignore/Check

This section lets you specify the names of parameters to be ignored or checked by the check and update commands and the names of properties that cause objects to be ignored during generation and check.

Add

Adds to the list a parameter or property name you have typed into the text field.

Remove

Removes the selected parameters or properties from the list.

Edit

This field list the parameters and properties that need to be checked.

Parameters to check

Lists only those parameters that are checked by the Check Against Source command.

Cadence recommends that you use the LAM file to set the parameters or provide an exhaustive list of parameters to be checked.

Environment variable: paramsToCheck

Parameters to ignore during check

Lists the parameters that are ignored by the Check Against Source command. Mismatches for any of the listed parameters are not reported by the check. The list inherits all the parameter names from Parameters to ignore during generation.

Environment variables: paramsToIgnore, paramsToIgnoreForCheck

Parameters to ignore during generation and update

Lists the parameters that are ignored by the following Connectivity commands: Generate – All From Source, Generate – Selected From Source, Generate – Clones, Update – Components And Nets, Update – Layout Parameters, Update – Schematic Parameters.

The following parameters are always ignored: instancesLastChanged, instNamePrefix, lxIgnoreParamForCAS, lxIgnoredParams, lxMFactorNum, lxParamsToIgnore, lxParamsToIgnoreForCheck, lxPlacementStatus, lxRounding, lxStopList, lxTimeStamp, lxUseCell, pin, posi

Environment variable: paramsToIgnore

Properties used to ignore objects during check

Lists the properties that cause pins and instances to be ignored by the Check Against Source command. Any object with one of the listed properties set to t is ignored during these operations. The list inherits all the property names from Properties used to ignore objects during generation and also includes lvsIgnore Property by default.

Environment variable: propsUsedToIgnoreObjsForCheck

Properties used to ignore objects during generation and update

Lists the properties that cause pins and instances to be ignored during the generate, check, and update commands listed above. Any object with one of the listed properties set to t is ignored during these operations.

By default, the list contains the following properties.

lxRemoveDevice ignore nlAction

Environment variable: propsUsedToIgnoreObjs

Inherited from Generation

Lists the parameters or properties that are inherited from the list defined for generation. Parameters and properties ignored for generation are always ignored for check.

Schematic Parameter Names

This section lets you specify the names of special parameters used in the schematic. Select the parameter you want to edit from the cyclic field and type the names in the text field.

Parallel-connected factor

Lists the names of the schematic parameters used to specify the multiplication factor (mfactor) for transistors. The default is m M. Layout XL checks each schematic instance for a parameter matching one of the names on the list and uses the value of that parameter to generate the appropriate number of parallel-connected devices in the layout.

Environment variable: mfactorNames

Series-connected factor

Lists the names of the schematic parameters used to specify the number of series-connected (sfactor) devices to be generated in the layout. The default is s S. Layout XL checks each schematic instance for a parameter matching one of the names on the list and uses the value of that parameter to generate the appropriate number of series-connected devices in the layout.

Environment variable: sfactorNames

Transistor

Lists the names of schematic parameters used to specify transistor width. The default is w and the value must be split among the generated parallel-connected devices during the Generate All From Source, Check Against Source, or Update Layout Parameters commands. Layout XL checks each schematic instance for one of the listed parameter names and updates the width values of the matching layout parameters such that number of mfactored instances * mfactorSplit value = source parameter value

Environment variable: transistorWidthParamNames

Capacitance

Lists the names of the schematic parameters that are used to specify capacitance. The default is c C.

The capacitance value must be split among the generated series-connected devices during the Generate All From Source, Check Against Source, or Update Layout Parameters commands. Layout XL checks each schematic instance for one of the listed parameter names and updates the capacitance values of the matching layout parameters accordingly.

Environment variable: capacitanceParamNames

Resistance

Lists the names of the schematic parameters that are used to specify resistance. The default is r R. The resistance value for a device must be split among generated series-connected devices during the Generate All From Source, Check Against Source, or Update Layout Parameters commands. Layout XL checks each schematic instance for one of the listed names and updates the values of the matching layout parameters accordingly.

Environment variable: resistanceParamNames

Inductance

Lists the names of the schematic parameters that are used to specify inductance. The default is l L. The inductance value for a device must be split among generated series-connected devices during the Generate All From Source, Check Against Source, or Update Layout Parameters commands. Layout XL checks each schematic instance for one of the listed names and updates the values of the matching layout parameters accordingly.

Environment variable: inductanceParamNames

Fingers

Lists the schematic parameters that are recognized as finger values when generating the layout. Layout XL checks each schematic instance for one of the listed parameter names and generates the device in layout with as many fingers, if applicable, based on the finger value associated with that parameter name. However, if fingerSplit is set to t, the fingers are split into separate devices when generating the layout.

Segments

Lists the schematic parameters that are set to indicate a single instance of a resistor with one or many segments. The name of each segment is unique and can be set by using the segmentParamNames environment variable. The default is segments.

Parameter Comparison, Generation and Update

This section lets you defines how CDF parameters and properties are compared during the Check Against Source, Update Layout Parameters, and Update Schematic Parameters.

Consider parameters only

Compares only CDF parameters in the schematic against the parameters and properties in the layout and reports (or updates) values that do not match, parameters that cannot be checked, and parameters that are missing from the layout view.

By default, parameters that are present in the schematic but missing from the layout are ignored. To propagate the missing parameters to the layout, make sure the Ignore missing parameters or properties check box is OFF.

Environment variable: checkParamsOnly

Consider parameters and properties

Checks CDF parameters and cell and instance properties in the schematic against the parameters and properties in the layout and reports (or updates) values that do not match, parameters that cannot be checked, and parameters that are missing from the layout view. Use this option to check or update user-defined properties in the schematic and layout or when you know that a particular instance has certain properties that you are interested in comparing or updating.

By default, parameters and properties that are present in the schematic but missing from the layout are ignored. To propagate the missing parameters and properties to the layout, make sure the Ignore missing parameters or properties check box is OFF.

Environment variable: checkParamsOnly

Ignore missing parameters or properties

Ignores parameters (and properties, if Consider parameters and properties is checked) that are present in one view but missing from the other. Switch off this option if, for example, your layout has additional parameters or properties that you want to propagate to the schematic using the Update Schematic Parameters command.

Environment variable: checkMissingParamsOrProps

Tolerance

Specifies the relative tolerance used when comparing values between the schematic and layout.

If a is the source parameter value, b is the layout parameter value, and e is the Tolerance then parameter values are considered equal if

| (a/b) - 1.0 | < e

Environment variable: paramTolerance

Always consider properties for generation

Transfers properties from schematic instances to layout instances during the Generate All From Source or Generated Selected From Source commands. Properties are transfered in addition to the CDF parameters, which are always transferred.

Update based on parameters to ignore for

Updates instance parameters, ignoring the parameters that are defined as parameters to be ignored for generation or the parameters to be ignored for check.

See Ignore Parameters and Terminals.

By default, the option updates instance parameters based on the parameters to check or parameters to ignore for check. In this case, only the parameters marked for checking are updated if they report a parameter or property mismatch during Check Against Source. The parameters that are ignored during the check do not report a mismatch and are not updated.

Environment variable: updateParamsForCheck

Update schematic parameter expressions with evaluated value

Updates the value of schematic parameters that are defined as expressions with the evaluated layout values, when the parameter values across the two views are different.

Environment variable: updateSchParamWithEvalValue

By default, the option is ON, which implies that all the schematic parameter values, including that of schematic parameters that are expressed as AEL or NLP expressions, are updated with the layout parameter values, when the evaluated schematic and layout parameter values are found to be different. For schematic parameter values that are expressions, the automatic update can overwrite the expression parameter values with the fixed value of the evaluated layout parameter. To avoid the automatic update, you can set updateSchParamWithEvalValue to nil.

Component Description Format

This section lets you specify the format of component description.

Evaluate CDF callbacks during generation and update

Causes all SKILL callbacks defined on CDF parameters to be evaluated by default when you run the Generate and Update commands in Virtuoso Layout Suite XL. Callbacks defined on buttons are not evaluated.

Environment variable: lxEvalCDFCallbacks

Use significant digits when calculating parameter values

Controls the number of significant digits used by Layout XL when calculating the value of layout CDF parameters. When the option is selected, the value it specifies overrides the setting of aelGetSignifDigits for calculations in the layout cellview. This lets you specify a different precision to be used in layout cellview calculations; for example, those involving Pcells.

The Use significant digits when calculating parameter values check box is available only if the shell environment variable CDS_Netlisting_Mode is set to Analog.

See Setting the CDS_Netlisting_Mode Environment Variable.

Presets

This section lets you specify the preset options.

Schematic driven

Reflects that all the form fields associated with the Preset options have their value set to ON, implying the option is selected.

Non schematic driven

Reflects that all the form fields associated with the Preset options have their value set to OFF, implying the option is deselected.

User defined

Reflects that the form fields associated with the Preset options are neither Schematic driven (all fields set to ON) nor Non schematic driven (all fields set to OFF).

If the Connectivity form is already open, the Configure tab is switched to User defined Preset mode. The associated environment variable is also set to the new form field value, after the form field value is applied. If the Connectivity form is opened again in the same Virtuoso session, it opens the Configure tab in User defined Preset mode, using the new form field value.

Options are configured to ensure layout edits reference the schematic

• Open connectivity reference: Lets you confirm whether or not the Virtuoso Schematic Editor is started when you launch Layout XL.
  Use the Connectivity Reference – Open field in the General tab of the Connectivity form to changes the preset value.
  Environment variable: lxSchematicDefaultApp
• Open connectivity reference during Edit In Place/Descend: Lets you confirm whether or not the source cellview is opened when you use the Edit In Place or Descend commands. When switched off, the layout cellview is still opened in Layout XL mode, but with no connectivity reference.
  Use the Connectivity Reference – Open connectivity reference during Edit In Place/Descend field in the General tab of the Connectivity form to change the preset value.
  Environment variables: openConnRef, openConnRefTab
• Update connectivity information when design is modified: Lets you confirm that the incremental connectivity extraction will be enabled, which updates the connectivity model whenever the design is modified.
  Use the Controls – Update connectivity information when design is modified to change the preset value in the Connectivity tab of the Connectivity form.
  Environment variable: extractEnabled
• Constraint-aware editing: Confirms that the Copy, Move, Stretch, and Rotate commands will honor the following constraints: Alignment, Fixed, Locked, Matched Parameters, Orientation, Matched Orientation, and Symmetry.
  Use the Constraint-aware editing to change the preset value in the General tab of the Connectivity form.
  Environment variable: constraintAwareEditing

• Display draglines: Confirms whether or not draglines will be displayed when using the Generate Selected From Source, Generate Clones, Move, and Stretch commands.
  Use the Display draglines field in the Display Tab of the Connectivity form to change the preset value.
  Environment variable: flightLineEnable
• Show wire editor flightlines: Lets you confirm whether or not flightlines will be displayed during Wire, Bus, and Guided Routing commands.
  Use the Show flightlines to change the preset value in the Interactive Section of the Wire Assistant GUI.
  Environment variable: autoUpdateFlightlines
• Net name display: Lets you confirm that net name labels will be displayed in the layout for the shapes that have associated net name labels.
  Use the Display net name labels to change the preset value in the Net Name Display Options form.
  Environment variable: netNameDisplayEnabled