minOppositeSpanSpacing

Specifies the spacing for a wire that has two neighboring shapes on opposite edges with a projected parallel run length greater than zero. Only neighbor wires that are classified as either ends or a joints are considered and the constraint applies only when the middle wire width is less than a specified width.

The constraint specifies spacing for each of the four neighbor categories (End-to-End, End-to-Joint, Joint-to-End, and Joint-to-Joint) shown in the following figure.

minOppositeSpanSpacing Quick Reference

Value Type

minOppositeSpanSpacing constraints have a DualValueTbl that must include a DualValue for each of the four categories in the following table and must be specified in the same order as shown in the table.

• endSpacing specifies the minimum spacing between an end neighbor edge to the middle wire.
• jointSpacing specifies the minimum spacing between a joint neighbor edge to the middle wire.

To satisfy the rule,

• For End-to-End and Joint-to-Joint cases, either both neighbor spacings must be greater than or equal to the minimum of the specified spacings, or at least one neighbor spacing must be greater than or equal to the maximum of the specified spacings in End-to-End or Joint-to-Joint.
• For End-to-Joint and Joint-to-End cases, both End-to-Joint and Joint-to-End spacings must be fulfilled individually. To fulfill one statement, either the spacing between the middle wire and the joint must be greater than or equal to joint spacing, or the spacing between the middle wire and the end must be greater than or equal to end spacing.

The following table shows the syntax for setting the minOppositeSpanSpacing constraint.

set_constraint_parameter -name width -Value f_width 
set_constraint_parameter -name endOfLineWidth -Value f_eolWidth 
set_constraint_parameter -name spanlength -Value f_spanLength 
[set_constraint_parameter -name length -Value f_minLength] 
[set_constraint_parameter -name jointWidth -Value f_jointWidth] 
[set_constraint_parameter -name exceptEdgeLength -Value f_edge]
[set_constraint_parameter -name maxlength -Value f_maxPRL] 

set_layer_constraint -constraint minOppositeSpanSpacing \
  -layer s_layerName -DualValueTbl { \
    f_spacing1_endToEnd     f_spacing2_endToEnd \
    f_spacing1_endToJoint   f_spacing2_endToJoint \
    f_spacing1_jointToEnd   f_spacing2_jointToEnd \
    f_spacing1_jointToJoint f_spacing2_jointToJoint}

PROPERTY LEF58_OPPOSITEEOLSPACING
"OPPOSITEEOLSPACING WIDTH f_width 
ENDWIDTH f_eolWidth [MINLENGTH f_minLength] 
[JOINTWIDTH f_jointWidth] JOINTLENGTH f_spanLength 
  [EXCEPTEDGELENGTH f_edge [PRL f_maxPRL]] 
  ENDTOEND     f_spacing1_endToEnd     f_spacing2_endToEnd
  ENDTOJOINT   f_spacing1_endToJoint   f_spacing2_endToJoint
  JOINTTOEND   f_spacing1_jointToEnd   f_spacing2_jointToEnd
  JOINTTOJOINT f_spacing1_jointToJoint f_spacing2_jointToJoint ;" ;

Parameters

The following parameters are used to determine which neighboring shapes represent ends and joints and when the constraint applies.

• endOfLineWidth (Value) The constraint applies only when a neighbor end-of-line width (eolWidth) is less than this value. If the jointWidth parameter is not specified, the endOfLineWidth value is also used for jointWidth. eolWidth measurements are illustrated in Illustration of eolWidth and minLength for End-to-End Spacing.
• spanLength (Value) The neighbor wire end edge is a joint (and not an end) if it has eolWidth less than endOfLineWidth and span (spanLength) greater than this value. Joints can be either a T or an L pattern. spanLength measurements are illustrated in Illustration of jointWidth, spanLength and jointToEdgeEndLength for Joint Spacing.
• width (Value) The constraint applies only when the middle wire is less than this value.
• jointWidth (Value, optional) The constraint applies only when a neighbor joint width is less than this value. If this parameter is not specified for the constraint, the endOfLineWidth value is used for jointWidth.
• jointToEdgeEndLength (Value, optional) The constraint applies only when the distance (jointToEdgeEndLength) from the end point of the joint to the end of the edge that contains the joint is greater than or equal to this distance.
• exceptEdgeLength (Value, optional) The constraint does not apply if both neighbor edges have a length (edgeLength) greater than or equal to exceptEdgeLength and, optionally, a projected parallel run length (PRL) less than or equal to maxLength. Neighbors can be ends or joints.
• exceptEdgeLengthPRL (ValueArrayValue, optional) The ValueArrayValue is mapped to a list of DualValue corresponding to exceptEdgeLength and maxLength or to a Value corresponding to just exceptEdgeLength. The ValueArrayValue can contain up to two entries, as shown below:
  

  set_constraint_parameter -name exceptEdgeLengthPRL \
  -ValueArrayValue { -DualIntValue { 0.072 0.01 } }

  The constraint does not apply if both neighbor edges have a length (edgeLength) greater than or equal to exceptEdgeLength and, optionally, a projected parallel run length (PRL) less than or equal to maxLength. Neighbors can be ends or joints.
• exceptDualLength (Value, optional) The constraint does not apply if both neighbor edges have a length (edgeLength) greater than and or equal to exceptDualLength. Neighbors can be ends or joints.
• length (Value, optional) The constraint applies only when the end-of-line length (minLength) is greater than or equal to this value along both sides. minLength measurements are illustrated in Illustration of eolWidth and minLength for End-to-End Spacing.
• maxLength (Value, optional) The constraint does not apply if both the end or joint neighbor edges have a length (edgeLength) greater than or equal to exceptEdgeLength and a projected parallel run length (PRL) less than or equal to maxLength.
  
  Illustration of eolWidth and minLength for End-to-End Spacing
  
  Illustration of jointWidth, spanLength and jointToEdgeEndLength for Joint Spacing
  

Examples

set_constraint_parameter -name width            -Value 0.08 
set_constraint_parameter -name endOfLineWidth   -Value 0.1 
set_constraint_parameter -name spanlength       -Value 0.15 
set_constraint_parameter -name exceptEdgeLength -Value 0.08
set_constraint_parameter -name maxlength        -Value 0.03 
set_layer_constraint -constraint minOppositeSpanSpacing \
  -layer Metal1 -DualValueTbl \
   { 0.11 0.13 \
     0.12 0.10 \
     0.12 0.10 \
     0.12 0.16 } \
   -row_interpolation snap_down \
   -row_extrapolation {snap_down snap_down}

PROPERTY LEF58_OPPOSITEEOLSPACING
  "OPPOSITEEOLSPACING WIDTH 0.08 ENDWIDTH 0.1 JOINTLENGTH 0.15
  EXCEPTEDGELENGTH 0.08 PRL 0.03
  ENDTOEND     0.11 0.13
  ENDTOJOINT   0.12 0.10
  JOINTTOEND   0.12 0.10
  JOINTTOJOINT 0.12 0.16 ; " ;

The following figure shows how the constraint is interpreted for this example.

Related Topics

Spacing Constraints