MOSIS FAQs: Warnings and Messages
The most frequently asked questions about warnings and messages issued by MOSIS automated manufacturability review.
Project Warnings
1.0 Path has reversing points at (248,-1260.4) in structure ABCDEF in record 1234.
2.0 160 paths with colinear points.
3.0 1 path with a reversing point.
4.0 Design pad location is symmetric; bonding orientation assumed same as submitted design file.
5.0 File contains non-GDSII names (alphanumeric or '_?$')
6.0 Text nodes ignored on layer(s): (This warning indicates an anomaly in the file that does not compromise our processing of the data.)
Messages
7.0 Coincident points.
See also Polygons and Winding Numbers.
1.0 Path has reversing points at (248,-1260.4) in structure ABCDEF in record 1234.
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Reversing points are a path doubled back on itself. Think of drawing a "T" without lifting your pencil.
1----3<-->2 | | v 4
2.0 160 paths with colinear points.
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Colinear points are three successive points in a path all in a straight line, so that the middle one is redundant, since it did not actually affect the path.
You can eliminate the warnings by cleaning up the redundant points. The redundant points by themselves do not cause a problem. They are brought to your attention so you can investigate further if you wish.
3.0 1 path with a reversing point.
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See number 1 above.
4.0 Design pad location is symmetric; bonding orientation assumed same as submitted design file.
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The pad location is symmetric. The "top" is defined by the way the layout was submitted.
When pad location is symmetric you cannot simply look at the surface of the chip's pads and determine top from bottom. This is not a fabrication issue.
5.0 File contains non-GDSII names (alphanumeric or '_?$').
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This warning indicates an anomaly in the file that does not compromise our processing of the data.
GDS syntax defines as standard all alphanumeric characters, the underbar ("_"), question mark ("?"), and the dollar sign ("$"). If a customer uses additional characters in GDS structure names MOSIS will generate a warning, but it will not affect our acceptance of or ability to process the layout. This most often comes up when customers use periods or dashes in stucture names. MOSIS limits GDS top structure characters to alphanumeric characters and '_?$.' Any other top structure characters will generate an error. You will need to edit the name of your top structure.
6.0 Text nodes ignored on layer(s):
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This warning indicates an anomaly in the file that does not compromise our processing of the data.
Text is usually used for labeling when you draw gds on a screen. Our manufacturability review code is simply explicitly stating that we are not processing the text as layout.
7.0 Coincident points.
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Coincident points are two (or more) successive points in a path (wire) or boundary (polygon) that are the same point repeated. No harm, but possibly worth investigating.