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NoHoles Rule

Syntax: NoHoles [Region region_expr] [MinArea area] [MinWidth width] [string]

If given in the layer block, the layer or region description (which is applied to the whole layer) is tested for clear area surrounded by dark area. Each such area is optionally tested. If the MinArea is given and positive and the clear area is smaller, a violation will be reported. If the MinWidth is given and positive, the clear area must be large enough so that for any edge, a rectangular projection along the edge extending into the interior by the given width will be clear. If not, a violation will be reported. If neither of the MinArea or MinWidth are given, then any such clear area found will be flagged as a violation.

The MinArea and MinWidth clauses are set by the minHoleArea and minHoleWidth constraints when importing Virtuoso technology data. Each constraint may have a separate reference string. To keep these distinguishable, the string can actually be three double quoted strings, e.g., the form is

"# rule description" "minHoleArea string" "minHoleWidth string"

This guarantees that the original reference strings are regenerated when the !dumpcds command is used to generate a Virtuoso technology file. If a component string doesn't exist, one can use "" (two double-quote marks) as a placeholder. Strings to the right that don't exist can be skipped entirely.


next up previous contents index
Next: Area Rules Up: Global Rules Previous: Connected Rule   Contents   Index
Stephen R. Whiteley 2017-04-09