strand_route
strand_route
{ -all [ true | false ]
| -set d_setObj
| -nets {s_netName…} }
[ -num_strands i_count ]
[ -strand_spacing f_distance ]
[ -strand_width f_width ]
[ -max_cluster_distance f_clusterDistance ]
[ -enable_bus_route [ true | false ] ]
[ -strap_strands [ true | false ] ]
Description
Routes all nets, specified nets, or nets in a set using multiple strands (fingers) between pins. In addition, stranded routing supports all connection types, including fat-to-fat, one-to-many (or many-to-one), and many-to-many, in all patterns, including straight, L, and Z patterns. For pattern path-find method, currently stranded routing only works for many-to-many connection type. For other connection types, a message is displayed.
If any of the nets to be routed are in a net_strand constraint group, then numStrands, strandSpacing, strandWidth, maxClusterDistance, and clusterDistance constraints, if set for the constraint group, are used for strand routing. Alternatively, the number of strands can be explicitly specified using command arguments, or automatically maximized based on the strand width (minWidth for the layer) and the strand spacing (via-to-via pitch). Command arguments can be used to override constraint settings.
When both clusterDistance and maxClusterDistance constraints are defined, the clusterDistance constraint is used. However, when only one of them is defined, the one that is defined is used for strand routing.
Strand routing produces parallel strands that are equal in width and evenly spaced. New wiring that fails this criterion (for example, due to obstructions) is discarded. If -enable_bus_route is true and strand routing fails, the router attempts to route strands as a bus. While this method can be successful, the resulting strands might not be parallel and evenly spaced.
Arguments
Examples
In this example, the fat pin-to-fat pin nets in the selected set are strand routed using the maximum number of strands that can be accommodated.
create_group -set [get_selection_set] -type net_strand -name StrandGroup
strand_route -set [get_selection_set]
Related Topics
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