minParallelViaSpacing

Specifies the minimum spacing for vias that have parallel edges with an overlap greater than 0. This constraint applies to cut layers only when vias do not share the same metal above or below and are on different nets.

Either minParallelWithinViaSpacing or minParallelViaSpacing can be specified for a cut layer, but not both.

minParallelViaSpacing Quick Reference

Value Type

minParallelViaSpacing constraints have a Value that represents the minimum required spacing for vias with overlapping parallel edges on the given cut layer.

set_layer_constraint -constraint minParallelViaSpacing \
 -layer s_layer -Value f_space

LAYER s_layer
  TYPE CUT ;
  SPACING f_space PARALLELOVERLAP ;

spacings(
( minParallelViaSpacing s_layer f_space )
)

Parameters

• oaConnectivityType (StringAsIntValue, optional) specifies the shapes to which this constraint applies, based on their connectivity, as given in oaConnectivityType Parameter Values for Via Spacing Constraints. This parameter is mutually exclusive with exceptConnectivityType.
• exceptConnectivityType (StringAsIntValue, optional) specifies the vias for which this constraint does not apply, based on their connectivity, as given in exceptConnectivityType Parameter Values. If this argument is not specified, same island vias are excluded. This parameter is mutually exclusive with oaConnectivityType.
  
  exceptConnectivityType Parameter Values

  String	Integer Value	Constraint does not apply to:
  sameNetConnectivity	1	Same net only
  sameIslandConnectivity	2	Via cuts connected by contiguous same metal
  directConnectShapesConnectivity	3	Via cuts directly connected by the same metal
  sameViaConnectivity	4	Via cuts with the same metal above and same metal below

Examples

This example sets the minimum spacing to 2.0 between cuts on layer cut1 that meet the following conditions:

• The cuts are not on the same metal shape
• The cuts have a parallel overlap (adjacent cut edges running parallel to each other have at least some portion of their edges on the same coordinates on the x or y axis)
  

  Format	Example
  Tcl	set_layer_constraint -constraint minParallelViaSpacing \ -layer cut1 -Value 2.0
  LEF 5.7	LAYER cut1 TYPE CUT ; SPACING 2.0 PARALLELOVERLAP ;
  Virtuoso	spacings( ( minParallelViaSpacing cut1 2.0 ) )

  

Related Topics

Via Construction Constraints