obstruction [xmin xmax ymin ymax layer]
where xmin xmax ymin ymax are four values representing the bounding box of the obstruction, in physical units of microns, and layer is the name of a routing layer covered by the obstruction.
The purpose of the obstruction command is to manually place obstructions in the path of the router. The most common use for this is to place fencing around the perimeter of a layout to prevent the router from using the area occupied by pins for general routing tracks. Additional obstructions may be placed over and under pins on the layout perimeter to keep the pins free of obstructing routes. Other uses include marking out areas intended for use by power routing, or masking off non-routable areas of a non-rectangular layout. Needless to say, careless use of the obstruction command can result in route failures, so use with caution.Values given to the obstruction command are in units of microns, and the obstruction is limited to the routing plane specified by the route layer type layer (e.g., "metal1"). To obstruct multiple layers, a separate obstruction command must be given for each layer.
obstruction is implemented as a built-in command in qrouter. It maintains the same syntax as the statement in the older configuration file format.
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Last updated: November 17, 2013 at 9:06pm