Offset layer.
This is a complex operation that creates an offset contour for the list of In layers. Different grow shapes can be used, detault is ellipse.
You can use the elements doc and tex to document the operation. This is often useful for later changes as the logic behind complex chains of operations is often not easy to follow by colleques and/or partners.
Sub elements:
In is the list of input layers.
dist is the distance for the offset (in um), default 0.1.
how defines the style (ellipse, miter, rectangle).


The attributes and elements are shown below, in a sorted per type fashion.
In case a list is printed after an element, it indicates that you can have many, otherwise it should be a single element. With a optional it tells the element is not required.

pdaDrcGeneralRule:DFM="..."  pdaDrcGeneralRule:drcExclude="..."  pdaDrcGeneralRule:level="..."  pdaDrcGeneralRule:rule="..." ... > ...
  <In> ... </In>
  <dist> ... </dist>    optional
  <how> ... </how>    optional
  <pdaDrcGeneralRule:doc> ... </doc>    optional
  <pdaDrcGeneralRule:groupRef> ... </groupRef>   list
  <pdaDrcGeneralRule:msg> ... </msg>    optional
  <pdaDrcGeneralRule:tex> ... </tex>    optional
  <pdaDrcGeneralRule:ticket> ... </ticket>   list


The schema file can be downloaded or viewed at xPDK_Layout.


Type pdaDrcGeneralRule

Define a design rule that is not layer or "polygon" / "geometric" based.
Design rules are available in different flavors, some of which can not be associated with layers; for example the name of the GDS cell that is required to be used for the design.
The rule is described in text and software may (or not) be able to implement them. Using the rule field gives designers an easy way to find more information on the DRC fail if it appears.


Reference a list of gds/app layers. This list is used as input for the operation. Type pdaGDSlayerReferenceList documentation:


Define the offset in um.


Different grow shapes determine the outer contour. Type pdaOPSoffsetLayerSelection documentation: Define the offset operation.


Type pdaExpression documentation:
Expression need to be commonly evaluated by many software, so having a restricted set of math / types and so on is key. In PDAFlow lib2/expr there is a yacc/lex parser available with some unit support as well as double / complex expressions. An alternative is tinyexpr, but this is more restrictive, so may be very unhandy for things like waveguide model expressions.


Short documentation on the why of the rule.
This information is useful for a design manual but can also be used in the user interface as additional information, like a 'on-hoover mouse move'. Type pdaDocumentation documentation:
This field allows some (short, few lines) documentation to be written. It can be a long string, but the idea is not to replace a design manual.
This fields is like tex which allows documentation in LaTex format; doc is restricted to plain text.


Type pdaGDSlayerReference documentation:


Use this field to combined related topics into groups. Type pdaIdentifier documentation:
Identifiers are used in the Python library for the getName() and setName() function and can thus be used to identify the different elements in list s.
In text the specification is a letter, followed by letters, numbers, underscore or dot. The XSD schema validation is a regular expression: [A-Za-z]([A-Za-z0-9_])*


Type pdaDrcWarningLevel documentation: Error/warning level for a DRC message.
Normal use is: warning / error.


DRC message to display in the user interface.
It is recommended that this is a short text as it may appear many times in the display (so much shorter then the 'doc' field).



Possibly long documentation on the why of the rule in LaTeX format. Type pdaTexDocumentation documentation: doc , but tex can be a long text in LaTex format to document the layer in more detail if needed.

You can document anything relevant for the topic you want to define.

Multiple paragraphs is fine. Format is Latex, so more complex content is possible.


Type pdaTicket documentation: