2 CST Access SKILL Functions

Introduction

This chapter provides information about DFII constraint objects using Cadence® SKILL language. There are two objects:

cstConstraintID can be layer constraint, layer-pair constraint, layer array constraint, or a simple constraint. It contains attribute values and parameters. The attribute values are represented in integer, float, string, or SKILL list. The parameters are represented in a SKILL list.
cstConstraintGroupID is the container of member constraints and member constraint groups.

The following figure displays the relationship between cstConstraintID, cstConstraintGroupID, tech, cellview, and objects, and their attributes. The attributes of cstConstraintID and cstConstraintGroupID have either Read (R) or Read/Write (RW) access.

The owner attribute in the following figure is for a constraint group associated with a particular owning object. This attribute returns a pointer to the owning object.

The following example illustrates that you can get the attributes of a member constraintGroup and a layerConstraint from the parentConstraintGroup, which contains them:

parentConstraintGroup~>objects~>

returns
(

(cst:0x080ef495 tech db:0x080ef892 cellview nil
 objType "constraintGroup" name "maximumYield" defName
 "userDefined" operator precedence owner nil
 objects (cst:0x080ee9ea cst:0x080ee9eb)
 )
(cst:0x080ee9df tech db:0x080ef892 cellview nil
 objType "layerConstraint" name "C__187" defName
 "minSpacing" layers ("METAL2") value 0.555
 params nil hard nil ID
 nil description nil
)

Constraint Functions

All constraint objects are defined by the constraint definition. Constraints always have a value associated with them and also a list of constraint parameters. There are four types of constraints: layer constraint, layer-pair constraint, layer array constraint, and simple constraint (has no layer).

The list of constraint functions is given below:

cstCreateConstraint

cstCreateConstraint(
g_cstConstraintGroupID
t_constraintDefName
g_layers
g_value
[ l_params ]
[ g_isHard ]
[ g_append ]
[ t_name ]
)
=> g_cstConstraintID / nil

Description

Creates a constraint in the constraint group (g_cstConstraintGroupID) with the specified constraint definition name (t_constraintDefName), layers, constraint value, constraint parameters, hard attribute, the position of the constraint with the members of the constraint group and the name of the constraint.

Arguments

g_cstConstraintGroupID	The ID of the constraint group, which is to own this constraint.
t_constraintDefName	Mapped DFII constraint name will be used to get a corresponding constraint definition name Must be an OA technology constraint.
g_layers	List of layer names, layer numbers, or LPPs.
g_value	SKILL expression for the constraint value. It can be an integer, a float, or a list.
l_params	A SKILL list of constraint parameters. The default value is nil. The input constraint parameters are in the following format: list(list(‘paramKeyWord{int \| float \| string \| list})...) For example, cst1~>params = list(list(‘ConnectivityType "sameNet") (‘list(‘PGNet t) =>((connectivityType "sameNet") (PGNet t))
g_isHard	A Boolean indicating whether the constraint must be met. If the value is nil, it means that it is a soft constraint. By default, the value is t.
g_append	A Boolean having a value as either nil or t. Having the value as nil puts this constraint to the first member in the constraint group. The present first constraint group member is moved to the second and subsequent members are also moved down in order. However, if the value is t, then the constraint is put to the end of the member in the constraint group. By default, the value is nil.
t_name	This is a user defined constraint name. The name will be automatically created if it is not specified. The default value is nil.

Value Returned

g_cstConstraintID	Returns the ID of the constraint, which is created in the constraint group.
`nil`	Returns nil if the constraint is not created.

Example

Layer constraint

tech    = techOpenTechFile("tech" "tech.db" "a") 
foundryCG = cstFindConstraintGroupIn(tech "foundry" 't)
cst1      = cstCreateConstraint(foundryCG "viaSpacing" list("viaLayer") 0.4
            list(list('distance 0.5) list('numCuts 2)))

Layer-pair constraint

cst2 = cstCreateConstraint(foundryCG "minSpacing" list("metal1" "metal2")1.2)

Layer-array constraint

cst3 = cstCreateConstraint(foundryCG "minTouchingDirEnclosure"
      list("metal1""metal2" "cont") 1.0)

You can use nil for layers to create a simple constraint:

cst4 = cstCreateConstraint(foundryCG "validLayers" nil list("metal1""metal2"))

Constraint with one-dimensional table value

 tech=techOpenTechFile("test" "tech.db" "r")

 foundryCG = cstFindConstraintGroupIn(tech "foundry" )

 c = cstCreateConstraint(foundryCG "minSpacing" list("Metal1")
   '(
   (("width") 0.3)
   (
    0.2 0.25
   0.3 0.26
   0.4 0.27
   0.5 0.28
   )
   );value
  '(
   ('spacingDirection "vertical")
   ('sameMask t)
   );params
  );cstCreateConstraint

printf("Minspacing 1D:\n %L\n %L\n" c~>value c~>params)

Constraint with two-dimensional table value

 tech=techOpenTechFile("test" "tech.db" "r")

 foundryCG = cstFindConstraintGroupIn(tech "foundry" )

 c = cstCreateConstraint(foundryCG "minSpacing" list("Metal1")
  '(
  (("width" "length") 0.3);header and default value
  (
    (0.2 2.0) 0.5
    (0.2 3.0) 0.2
    (0.7 2.0) 0.2
    (0.7 3.0) 0.7
    );table
    );value
   '(
     ('spacingDirection "vertical"
    ('sameMask t)
   );parameters
  );cstCreateConstraint

printf("Minspacing 2D:\n %L\n %L\n" c~>value c~>params)

Constraint with one-dimensional parameter table

 tech=techOpenTechFile("test" "tech.db" "r")

 foundryCG = cstFindConstraintGroupIn(tech "foundry" )

 c = cstCreateConstraint(foundryCG "minDensity" list("Metal1")
   '(
    (("step") 10.0);header and default value
    (
    10  20.0
    20  30.0
    );table
   );value
   '(
    ('windowStepSize ((("window")) (60.0 100.0 120.0 200.0)))
   );params
  )

printf("minDensity:\n %L\n %L\n" c~>value c~>params)
techCloseTechFile(tech)

cstDeleteConstraint

cstDeleteConstraint( 
g_cstConstraintID 
)
=> t / nil

Description

Deletes the constraint from any of the constraint groups it is a part of. Its value and constraint parameters are also deleted.

Arguments

g_cstConstraintID

The identification of the constraint.

Value Returned

`t`	Returns t when `cstDeleteConstraint` successfully deletes the constraint.
`nil`	Returns `nil` when the pass-in constraint cannot be deleted.

Examples

cstDeleteConstraint(cstnet1l)

cstFindCutClassConstraintByName

cstFindCutClassConstraintByName(
d_constraintGroupId
tx_layer
t_name
)
=> d_cutClassConstraintId / nil

Description

Returns the database ID of the cut class constraint with a given cut class name, layer, and constraint group.

For more details, see cutClasses.

Arguments

d_constraintGroupId	Database ID of the constraint group in which to search.
tx_layer	Layer number or layer name to be searched.
t_name	Name of the cut class.

Value Returned

d_cutClassConstraintId	Database ID of the cut class constraint.
`nil`	The cut class constraint was not found.

Example

Retrieves the database ID of a cut class constraint named BAR0.2 on layer BAR0 in the constraint group referenced by grp.

cstId = cstFindCutClassConstraintByName(grp "BAR0" "BAR0.2")

cstFindCutClassConstraintBySize

cstFindCutClassConstraintBySize(
d_constraintGroupId
tx_layer
n_width
n_length
g_checkOrientation
)
=> d_cutClassConstraintId / nil

Description

Searches the specified layer in the specified constraint group and returns the first cut class constraint with the specified width and length. If g_checkOrientation is set to t, the orientation of the cut class will also be included as part of the search.

For more details, see cutClasses.

Arguments

d_constraintGroupId	Database ID of the constraint group in which to search.
tx_layer	Layer number or layer name to be searched.
n_width	Width of the cut shape to be searched.
n_length	Length of the cut shape to be searched.
g_checkOrientation	When set to `t`, searches cut classes for which the `fixedOrientation` attribute is set to `t`. If none are found, searches for cut classes that have `fixedOrientation` set to `nil`.

Value Returned

d_cutClassConstraintId	Database ID of the cut class constraint.
`nil`	No matching cut class constraint was found on the specified layer.

Example

Retrieves the database ID of a cut class constraint with width 0.2, length 0.3, and a fixed orientation on the layer BAR0.

cstId = cstFindCutClassConstraintBySize(grp "BAR0" 0.2 0.3 t)

cstGetUnreferencedConstraints

cstGetUnreferencedConstraints(
{ d_techID | d_cellViewID }
)
=> l_unreferencedConstraints / nil

Description

Returns all the unreferrenced constraints not belonging to any constraint group in a database (a technology database or a cellview).

A slow performance could be experienced if the databases contain multiple constraints or constraint groups, and use either the cstGetUnreferencedConstraints or cstGetConstraintGroups API.

Arguments

d_techID	The identification of the technology database.
d_CellViewID	The identification of the cellview.

Value Returned

l_unreferencedConstraints	Returns the identification of all the unreferenced constraints.
`nil`	Returns nil if there are no unreferenced constraints available for a constraint group in a database.

Example

list_constraints = cstGetUnreferencedConstraints(techDB1)

foreach(danglingConstraint cstGetUnreferencedConstraints(cellViewId_1)

  cstDeleteConstraint(danglingConstraint)

cstGet1DTableValue

cstGet1DTableValue( 
d_ConstraintID 
n_index1
)
=> n_value

Description

Returns the value of the table for the given index. The index varies depending on the constraint. It can be a width or a length.

Arguments

d_ConstraintID	The ID of the constraint.
n_index1	The index can be a width or a length.

Value Returned

n_value

The value of the table at the given index.

Example

cstNDrule2_Int1DTbl~>value =

list(list(list("width") 0.4)

list(0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45)

((("width") 0.4)

0.1 0.15 0.2 0.25 0.3

0.35 0.4 0.45

cstGet1DTableValue(cstNDrule2_Int1DTbl 0.1)

cstGet2DTableValue

cstGet2DTableValue( 
d_ConstraintID 
n_index1
n_index2
)
=> n_value

Description

Returns the value of the table for the given indexes.

Arguments

d_ConstraintID	The ID of the constraint.
n_index1	The index can be a width or a length, which usually correspond to the row of the table.
n_index2	The index can be a width or a length, which usually correspond to the column of the table.

Value Returned

n_value

The value of the table at the given indexes.

Example

Int2DTbl~>value

((("width" "length") 0.33)

((0.0 0.1) 0.22

(0.0 0.3) 0.32

(0.2 0.1)

0.23

(0.2 0.3) 0.0

(0.4 0.1) 0.24

(0.4 0.3) 0.34

cstGet2DTableValue(Int2DTbl 0.0 0.1)

cstGetTwoWidthTableValue

cstGetTwoWidthTableValue( 
d_ConstraintID 
n_index1
n_index2
n_index3
)
=> n_value

Description

Applies to the twoWidth table. It only returns the spacing value for a given width1, width2, and length.

Arguments

d_ConstraintID	The ID of the constraint.
n_index1	This is the first width or width1.
n_index2	This is the second width or width2.
n_index3	This should be the length.

Value Returned

n_value

The value of the given width1, width2, and length.

Example

twoWidthCst = cstCreateConstraint(foundry "minSpacing" list("metal1") list(list(list("twoWidths" "length") 0.0)

list(list(0.0 -0.001) 0.15

list(0.0 0.0) 0.2

list(0.0 1.5) 0.5

list(0.0 3.0) 1.0

list(0.25 -0.001) 0.2

list(0.25 0.0) 0.25

list(0.25 1.5) 0.5

list(0.25 3.0) 1.0

list(1.5 -0.001) 0.5

list(1.5 0.0) 0.5

list(1.5 1.5) 0.6

list(1.5 3.0) 1.0

list(3.0 -0.001) 1.0

list(3.0 0.0) 1.0

list(3.0 1.5) 1.0

list(3.0 3.0) 1.2)) list(list('widthLengthTableType "twoWidthPRL")))

cstGetTwoWidthTableValue(twoWidthCst 0.25 0.25 0.1)

cstIsId

cstIsId(
g_id
)
=> t / nil

Description

Returns a Boolean that indicates whether the specified ID is a constraint ID.

Arguments

g_id

The ID of an object.

Value Returned

`t`	Returned if the given ID is a constraint ID.
`nil`	Returned if the given ID is not a constraint ID.

Example

cg1OnTopCV = cstCreateConstraintGroupIn(cv "cg1OnTopCV" "userDefined")

> cst:0x107ae616

cstIsId(nil)

> nil

cstIsId(cv)

> nil

cstIsId(cg1OnTopCV)

> t

Constraint Group Functions

The list of constraint group functions is given below:

cstAddToConstraintGroup

cstAddToConstraintGroup(
g_cstConstraintGroupID
g_memberConstraintGroupID
[ g_append ]
)
=> t / nil

Description

Adds a constraint group to be a member constraint group of the containing constraint. You can position the constraint group at the beginning of the members or at the end of the members with g_append. The default value for g_append is nil, which means that add the constraint group to the beginning of the members. The member constraint group cannot be owned by other objects.
Note: A member constraint group cannot be added to itself.

Arguments

g_cstConstraintGroupID	The ID of the constraint group.
g_memberConstraintGroupID	The ID of the member constraint group.
g_append	A Boolean having a value as either nil or t. Having the value as nil puts this constraint to the first member in the constraint group. The present first constraint group member is moved to the second and subsequent members are also moved down in order. However, if the value is t, then the constraint is put to the end of the member in the constraint group. By default, the value is nil.

Value Returned

`t`	Puts the constraint to the end of the member in the constraint group.
`nil`	Puts the constraint at the beginning of the members in the constraint group.

Example

cstAddToConstraintGRoup (netcstGroup1 cvCstGroup1 nil)

Here, nil is for append argument.

cstAddToConstraintGroup(containingCG1 containedCG2 t)

cstCreateConstraintGroupIn

cstCreateConstraintGroupIn(
{ d_techID | d_cellViewID }
t_constraintGroupName
[ t_constraintGroupDefName ]
[ g_operator ]
)
=> g_cstConstraintGroupID / nil

Description

Creates a constraint group in the technology database (that is, techDb) or a cellview with arguments of the database ID, constraint group name, constraint group definition name and operator symbol.

Arguments

d_techID	The ID of the technology database.
d_cellViewID	The ID of the cellview.
t_constraintGroupName	The group name that needs to be specified by the user.
t_constraintGroupDefName	For technology database, the DFII constraint group definition name can be `"userDefined"`, `"foundry"`, `"implicit"`, `"default"`, and `"cutClass"`. However for cellview, the DFII constraint group definition name can be `"userDefined"`, `"implicit"`, and `"default"`. The default name is `"userDefined"`.
g_operator	The operator symbol can be 'precedence, 'and or 'or. The default symbol is 'precedence.

Value Returned

g_cstConstraintGroupID	Returns the ID of the constraint group, which is created in the technology database or a cellview.
`nil`	Returns nil if the constraint group is not created.

Example

Create a constraint group techCstGroup1 in a techDB (techDB1) with the default constraint group definition ("default") and precedence ('precedence).

techcstGroup1 = cstCreateConstraintGroupIn(techDB1 "techcstGroup1”).

Create a constraint group techCG2 in a techDB (techDB1) with a constraint group definition of "foundry" and a precedence of 'or.

techCG2 = cstCreateConstraintGroupIn(techDB1 "spacingCG1" "foundry" 'or)

Create a constraint group cvcstGroup1 in a cellview (cv1).

cvcstGroup1 = cstCreateConstraintGroupIn(cv1 "cvcstGroup1”).

cstCreateConstraintGroupOn

cstCreateConstraintGroupOn(
g_object
t_constraintGroupDefName
[ g_operator ]
)
=> g_cstConstraintGroupID / nil

Description

Creates a constraint group on an object (for example, net, term, and so on) with arguments of the object ID, constraint group definition name, and operator symbol. The constraint group definition name is required while constraint group operators are optional for this SKILL function.

Arguments

g_object	An object in the design, such as net, route, and so on.
t_constraintGroupDefName	The DFII constraint group definition name can be as follows:
	Constraint Group	Description	Objects
	`implicit`	Specifies the semantics for the constraint group associated with individual objects.	all objects
	`default`	Specifies the semantics for the constraint group associated with a container object. Constraints in these constraint groups apply to the contained objects but not to the container object.	Net, term, route, figGroup
	`inputTaper`	Specifies the semantics for the input taper constraint group.	Net
	`outputTaper`	Specifies the semantics for the output taper constraint group.	Net
	`taper`	Specifies the semantics for the taper constraint group.	term, pin, instTerm
	`shielding`	Specifies the semantics for the constraint group associated with a shielded bitNet. The shielding constraint group can also be associated with a group of nets that must be shielded.	Net
	`transReflexive`	Specifies the semantics for constraint groups where the constraints apply between all objects within a container and all relevant objects outside of that container. The constraints do not apply between objects within the container.	group
	`reflexive`	Specifies the semantics for constraint groups where the constraints apply between the relevant objects within a container, but do not apply to objects outside of the container.	group
	`interChild`	Specifies the semantics for constraint groups where the constraints apply between objects within child containers but do not apply between objects within the parent container. InterChild constraint groups can be considered as applying to a subset of the relationships defined by the Reflexive semantics.	group
g_operator	Returns the ID of the constraint group that is created on an objects.

Value Returned

g_cstConstraintGroupID	Returns the ID of the constraint group, which is created in the technology database or a cellview.
`nil`	Returns nil if the constraint group is not created on an object.

Example

netcstGroup1 = cstCreateConstraintGroupOn (net1 "inputTaper" "'precedence").

netCG2 = cstCreateConstraintGroupOn(net1 "outputTaper" 'or)

cstDeleteConstraintGroup

cstDeleteConstraintGroup(
g_cstConstraintGroupID
)
=> t / nil

Description

Deletes the constraint group (g_cstConstraintGroupID). The contained constraints in the constraint group are not automatically deleted when the constraintGroup is deleted.

Arguments

g_cstConstraintGroupID

The identification of the constraint group.

Value Returned

`t`	Returns t when the constraint group is successfully deleted.
`nil`	Returns nil when unable to find a constraint group that is to be deleted.

Example

cstDeleteConstraintGroup(cstGroupID)

cstFindConstraintGroupIn

cstFindConstraintGroupIn(
{ d_techID | d_cellViewID }
t_constraintGroupName
[ g_localOnly ]
)
=> g_cstConstraintGroupID / nil

Description

Returns a constraint group ID (g_cstConstraintGroupID) from a database ID with constraint group name and a Boolean flag (g_localOnly).

Arguments

d_techID	The ID of the technology database.
d_cellViewID	The ID of the cellview.
t_constraintGroupName	The name of the constraint group.
g_localOnly	Looks for a constraint group in an ITDB graph if the database ID is a technology database.The default value is `nil`.

Value Returned

g_cstConstraintGroupID	Returns the ID of the constraint group that is found in the database.
`nil`	Returns `nil` if unable to find any constraint group in the database.

Example

foundryCGId = cstFindConstraintGroupIn(techDB1 "foundry" 't)

cv1CG1 = cstFindConstraintGroupIn(cellView1 "cvCG1")

cstFindConstraintGroupOn

cstFindConstraintGroupOn(
g_object
t_constraintGroupDefName
)
=> g_cstConstraintGroupID / nil

Description

Returns a constraint group ID (g_cstConstraintGroupID) from an object (g_object) with constraint group definition name.

Arguments

g_object	An object in the design, such as net, route, and so on.
t_constraintGroupDefName	The DFII constraint group definition name. For information on this argument, refer to the cstCreateConstraintGroupOn function.

Value Returned

g_cstConstraintGroupID	Returns the ID of the constraint group that is found in an object.
`nil`	Returns nil if unable to find any constraint group in an object.

Example

netcstGroup1 = cstFindConstraintGroupOn(net1 "inputTaper")

cstFindFirstConstraint

cstFindFirstConstraint(
d_ConstraintGroupID
t_constraintDefName
[ ( tx_layer [ tx_purpose ] )... ]
[ l_params ]
[ g_onlyHard ]
)
=> d_ConstraintID / nil

Description

Searches a constraint group in the hierarchical order and returns the ID of the first constraint found with the given name, layers, purposes, and params. If the onlyHard argument is not specified, the first matching constraint is returned and it is possible that it is a hard constraint. If the onlyHard argument is specified, then the first matching hard constraint is returned.

Arguments

d_ConstraintGroupID	The ID of the constraintGroup in which the constraint is searched.
t_constraintDefName	Mapped DFII constraint name will be used to get a corresponding constraint definition name.
tx_layer...	List of layer names, layer numbers, or LPPs.
l_params	A SKILL list of constraint parameters. The default value is nil. The input `constraintParams` is in a format of: list(list(‘paramKeyWord{int \| float \| string \| list})...) For example, cst1~>params = list(list(‘ConnectivityType "sameNet") (‘list(‘PGNet t) =>((connectivityType "sameNet") (PGNet t))
g_onlyHard	If this argument is not specified, the first matching constraint is returned and it is possible that it is a hard constraint. If the argument is specified, then the first matching hard constraint is returned.

Value Returned

d_ConstraintID	Returns the ID of the constraint, if found.
`nil`	Returns nil if the matching constraint is not found.

Example

cstfound = cstFindFirstConstraint(foundry "minSpacing" list("Metal2"))

cstfound = cstFindFirstConstraint(foundry "minSpacing" list("Metal2") nil t)

cstfound = cstFindFirstConstraint(foundry "minSpacing" list(list("Metal1" "drawing")) nil t)

cstGetConstraintGroups

cstGetConstraintGroups(
g_cstConstraintID
)
=> l_containingConstraintGroups / nil

Description

Returns all the containing constraint groups for the constraint (g_cstConstraintID).

Arguments

g_cstConstraintID

The identification of the constraint.

Value Returned

l_containingconstrainGroups
	Returns all the constraint groups that contain the particular constraint.
`nil`	Returns `nil` when the particular constraint is not in any constraint groups.

Example

list_CGs = cstGetConstraintGroups(constraintId)

cstGetDefaultConstraintGroupIdByName

cstGetDefaultConstraintGroupIdByName(
d_cellView
t_ConstraintGroupName
)
=> g_constraintGroupId / nil

Description

Returns the constraint group ID that is used by the default constraint group name on the objects of the cellview.

Arguments

d_cellView

The cellview is allied with the specified constraint group and application type.

t_ConstraintGroupName

If the constraint group is in the cellview, this function returns "dsn:<constraintGroup name>". For example, "dsn:default" and "dsn:cg1".

If the cellview has no default constraint group, but it is attached to the technology database that has a default constraint group, this function returns "tech:default".

If the constraint group is in the root technology database of the cellview, this function returns "<constraintGroup name>". For example, "foundry".

If the constraint group is in the referenced technology database of the root technology database of the cellview, this function returns "tech:<constraintGroup name>(<reference techDB name>". For example, "tech:cg1(refTechDB2)".

Value Returned

g_constrainGroupId	Returns the consraint group ID.
`nil`	Returns nil when unable to find the constraint group ID.

Examples

cstGetDefaultConstraintGroupIdByName(cv "myCG")

=> cst:0x2b2ddfaa

cstGetDefaultConstraintGroupIdByName(cv "tech:default")

=> cst:0x2bc2df9a

cstGetDefaultConstraintGroupName

cstGetDefaultConstraintGroupName(
d_cellView
t_type
[ g_fallBackToWireCG ]
)
=> t_constraintGroupName / nil

Description

Returns the name of the default constraint group that is used on the objects of the cellview according to the specified application type.

Arguments

d_cellView	The cellview is allied with the specified constraint group and application type.
t_type	The four valid application types are `Setup`, `Wire` `Via`, and `Taper`.
g_fallBackToWireCG	Applies to the `userWire` constraint group. The default value is `t.` When set to `t` and `userWire` constraint group is not set, it returns the value for wire constraint group. When set to `nil`, it returns the value of `userWire` constraint group.

Value Returned

t_constrainGroupName

If the constraint group is in the cellview, this function returns "dsn:<constraintGroup name>". For example, "dsn:default" and "dsn:cg1".

If the cellview has no default constraint group, but its attached to the technology database that has a default constraint group, this function returns "tech:default".

If the constraint group is in the root technology database of the cellview, this function returns "<constraintGroup name>". For example, "foundry".

nil

Returns nil when unable to find constraint group name.

Examples

cstGetDefaultConstraintGroupName(cv1 "Wire")

=> "tech:default"

cstGetDefaultConstraintGroupName(cv2 "Wire")

=> "default"

cstGetDefaultConstraintGroupName(cv1 "Setup")

=> ""

cstGetDefaultConstraintGroupName(cv3 "Wire")

=> "tech:cg1(refTechDB2)"

cstGetDefaultConstraintGroupNameById

cstGetDefaultConstraintGroupNameById(
d_cellView
)
=> t_constraintGroupName / nil

Description

Returns the name of the default constraint group name by cellview and constraint group ID.

Arguments

d_cellView

The cellview is allied with the specified constraint group and application type.

Value Returned

t_constrainGroupName

If the constraint group is in the cellview, this function returns "dsn:<constraintGroup name>". For example, "dsn:default" and "dsn:cg1".

If the constraint group is in the root technology database of the cellview, this function returns "<constraintGroup name>". For example, "foundry".

nil

The given cellview does not have a default constraint group name.

Examples

cstGetDefaultConstraintGroupNamebyId(cv1 cgId)

=> "tech:default"

cstGetDefaultConstraintGroupNamebyId(cv2 cgId2)

=> "myCG"

cstGetFoundryCGName

cstGetFoundryCGName(
)
=> t_constraintGroupName

Description

Returns the name of the alternate foundry constraint group. If there is no alternate foundry constraint group specified, it returns the name of the foundry constraint group.

Arguments

None

Value Returned

t_constraintGroupName

The name of the alternate foundry constraint group (if specified) or the foundry constraint group.

Example

Returns the name of the alternate foundry constraint group specified:

cgName = cstGetFoundryCGName()

cstGetFoundryConstraintGroup

cstGetFoundryConstraintGroup(
d_techID
)
=> d_cgID / nil

Description

Returns the database ID of the alternate foundry constraint group specified for a given technology file. If there is no alternate foundry constraint group specified, it returns the ID of the foundry constraint group.

Arguments

d_techID

Database ID of the technology file to be queried.

Value Returned

d_cgID	Database ID of the alternate foundry constraint group (if specified) or the foundry constraint group.
nil	Returns nil when the foundry constraint group cannot be returned due to the wrong argument or other error condition.

Example

Returns the alternate foundry constraint group specified for the technology file assigned to pointer tfId:

cgID = cstGetFoundryConstraintGroup(tfId)

cstSetDefaultConstraintGroupName

cstSetDefaultConstraintGroupName(
d_cellview
t_constraintGroupName
t_type
)
=> t / nil

Description

Sets the specified constraint group name to be used as the default constraint group on the objects of the cellview according to the specified application type.

Arguments

d_cellview

The cellview is allied with the specified constraint group and application type.

t_constraintGroupName

The name of the constraint group.

If t_constraintGroupName has prefix dsn:, this function only finds the constraint group in the cellview with the string.

If t_constraintGroupName has prefix tech:, this function only finds the constraint group from the technology database graph attached to the cellview with the string.

If t_constraintGroupName has neither dsn: nor tech: as a prefix, this function finds the constraint group from the cellview first and then from the technology database graph attached to the cellview with the string

t_type

The four valid application types are "Setup", "Wire" "Via", and "Taper".

Value Returned

`t`	Returns t when the specified constraint group is used as the default constraint group.
`nil`	Returns nil when unable to use the specified constraint group as the default constraint group.

Example

cstSetDefaultConstraintGroupName(cv1 "default" "Wire")

cstSetDefaultConstraintGroupName(cv1 "dsn:default" "Wire")

cstSetDefaultConstraintGroupName(cv1 "tech:foundry" "Setup")

cstSetDefaultConstraintGroupName(cv1 "foundry" "Wire")

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Virtuoso Unified Custom Constraints SKILL ReferenceProduct Version IC23.1, November 2023

2

CST Access SKILL Functions

Introduction

Constraint Functions

cstCreateConstraint

Description

Arguments

Value Returned

Example

cstDeleteConstraint

Description

Arguments

Value Returned

Examples

cstFindCutClassConstraintByName

Description

Arguments

Value Returned

Example

cstFindCutClassConstraintBySize

Description

Arguments

Value Returned

Example

cstGetUnreferencedConstraints

Description

Arguments

Value Returned

Example

cstGet1DTableValue

Description

Arguments

Value Returned

Example

cstGet2DTableValue

Description

Arguments

Value Returned

Example

cstGetTwoWidthTableValue

Description

Arguments

Value Returned

Example

cstIsId

Description

Arguments

Value Returned

Example

Constraint Group Functions

cstAddToConstraintGroup

Description

Arguments

Value Returned

Example

cstCreateConstraintGroupIn

Description

Arguments

Value Returned

Example

cstCreateConstraintGroupOn

Description

Arguments

Value Returned

Example

cstDeleteConstraintGroup

Description

Arguments

Value Returned

Example

cstFindConstraintGroupIn

Description

Arguments

Value Returned

Example

cstFindConstraintGroupOn

Description

Arguments

Value Returned

Virtuoso Unified Custom Constraints SKILL Reference
Product Version IC23.1, November 2023