minAreaEdgeLength

Specifies the minimum metal area for polygons on a layer that is larger than minArea and required when certain conditions exist:

If all edges of the polygon are less than a given length
If a rectangle of a given length and width cannot fit inside the polygon

For some processes, the area of a shape must be larger unless the shape has two adjacent edges, one of which is longer than a given length, and the other of shorter than a given length.

minAreaEdgeLength Quick Reference

Constraint Type	Layer
Value Types	`AreaValue`
Database Types	Design, Technology
Scope	design, foundry
Category	Area
Group Operators	AND

Value Type

AreaValue

Specifies the minimum metal area (in user units²) for polygons on the layer.

Optional Parameters

`shapeType`	Specifies the type of shapes to which the rule applies. Type: `IntValue` 0 All shapes (default) 1 Rectangles only 2 Polygons/nonrectangular objects only
`exceptEdgeLength`	Specifies that the rule does not apply for polygons with at least one edge longer than this value in user units. This parameter cannot be specified with the `width` parameter for a layer. Type: `Value`
`exceptMinEdgeLength`
	Specifies that the rule applies only if at least one edge has a length greater than or equal to this value in user units. Type: `Value`
`exceptMinSize`	Specifies that the rule applies only for shapes in which a minimum sized rectangle, given by the two values representing width and length, cannot fit. This parameter cannot be specified with the `width` or `exceptMinSizeArray` parameters for a layer. Type: `DualValue`
`exceptMinSizeArray`
	Specifies that the rule applies for shapes in which a rectangle of any width/length pair, given by this parameter, cannot fit. This parameter cannot be used with `exceptMinSize`. Type: `LayerArrayValue`
`exceptStep`	Specifies that the rule does not apply for a polygon that has an edge with length greater than or equal to the first value and an adjacent edge of length less than the second value in user units. Type: `DualValue`
`width`	Specifies that the rule does not apply for any wire with all widths greater than or equal to this value, in user units. This parameter cannot be specified with the `exceptEdgeLength` or `exceptMinSize` parameters for a layer. Type: `Value`

Examples

Example 1: minAreaEdgeLength with width Parameter

Requires that all polygons on Metal1 must have a minimum area of 0.18 except when all widths for the wire are greater than or equal to 0.2, then its minimum area must be 0.1.

set_layer_constraint -constraint minArea -layer Metal1 -AreaValue 0.1
set_constraint_parameter -name width -Value 0.2
set_layer_constraint -constraint minAreaEdgeLength -layer Metal1 -AreaValue 0.18

Illustration of minAreaEdgeLength with width Parameter

Example 2: minAreaEdgeLength with exceptEdgeLength

Requires that all polygons on Metal1 must have a minimum area of 0.04, except if a polygon has at least one edge that is greater than or equal to 0.21, then its minimum area must be 0.03.

set_layer_constraint -constraint minArea -layer Metal1 -AreaValue 0.03
set_constraint_parameter -name exceptEdgeLength -Value 0.21
set_layer_constraint -constraint minAreaEdgeLength -layer Metal1 -AreaValue 0.04

Illustration of minAreaEdgeLength with exceptMinLength Parameter

Example 3: minAreaEdgeLength with exceptMinSize

Requires that all polygons on Metal1 must have a minimum area of 0.6, except if a rectangle of size 0.1 by 0.2 can fit inside the polygon, then the polygon’s minimum area must be 0.5.

set_layer_constraint -constraint minArea -layer Metal1 -AreaValue 0.4
set_constraint_parameter -name exceptMinSize -DualValue {0.1 0.2}
set_layer_constraint -constraint minAreaEdgeLength -layer Metal1 -AreaValue 0.6

Illustration of minAreaEdgeLength with exceptMinSize Parameter

Example 4: minAreaEdgeLength with exceptStep

Requires that all polygons on Metal1 must have a minimum area of 0.017, except when the polygon has an edge length greater than or equal to 0.12 with an adjacent edge that is less than 0.05, then it must have a minimum area of 0.015.

set_layer_constraint -constraint minArea -layer Metal1 -AreaValue 0.015
set_constraint_parameter -name exceptStep -DualValue {0.12 0.05}
set_layer_constraint -constraint minAreaEdgeLength -layer Metal1 -AreaValue 0.017

Illustration of minAreaEdgeLength with exceptStep Parameter

Example 5: minAreaEdgeLength with shapeType

Requires that all rectangles on Metal1 must have a minimum area of 0.8, while any other polygons (non-rectangular objects) must have a minimum area of 0.10.

set_layer_constraint -constraint minArea -layer Metal1 -AreaValue 0.08
set_constraint_parameter -name shapeType -IntValue 2
set_layer_constraint -constraint minAreaEdgeLength -layer Metal1 -AreaValue 0.10

Illustration of minAreaEdgeLength with shapeType Parameter

Virtuoso Space-based Router Constraint Reference
Product Version IC23.1, June 2023