LS: Layout Scanner

LS is a vapour-ware. There is hardly any development now.

The role of LV is to "scan" a layout to detect areas that can be improved on. To illustrate the value of LV, one such "scan" feature is discussed here.

Consider a net with 3 fan-outs from a P&R layout:

The following diagrams show the shortest connection from A to B, A to C and A to D assuming that only rectilinear routing is used. Obvious, the connection from A to C in the layout is much longer than the shortest connection.

If we also consider connections from any pair of inputs, the connection between C and D is also very much longer than the shortest connection, as illustrated below.

A connection that is much longer than the shortest connection is usually due to poor floorplan or congestion. A tool than can feedback such connections is useful for the P&R engineer to make further improvement on the quality of the layout.

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