Starting with version 0.22, KLayout offers a library concept. @@ -50,6 +52,22 @@ name of the library file minus the extension.
+Layout files by declaration: + Starting with version 0.30.8, KLayout supports declaration of static libraries by + a library definition file. This is an alternative mechanism to the "libraries" folder + and has a number of advantages: +
++ This feature is limited to static libraries - i.e. libraries declared by library + definition files cannot include PCells. PCells are an exclusive feature of coded + libraries. +
++ Static libraries, whether defined by a library declaration file or implicitly from the + "libraries" folder, are automatically reloaded, when the file changes. If this feature + is not desired, you can disable automatic reload in the Setup dialog and manually refresh + the libraries if required. +
+ ++ Unlike other systems, libraries are not external references for KLayout. Instead, a library + is essentially a copy source. When you use a library cell, it is copied into your + working layout and is weakly linked to the original place. You can refresh the library, + which will also refresh the copy. This process is called "replication". +
+ ++ This approach implies a memory adder, but has a number of benefits: +
+ ++ The design also implies that libraries are read-only. You edit the working + copy only - library cells pulled into the layout are copies that cannot and + should not be edited, as they are restored from their original source + occasionally. Libraries should be thought of as external deliveries similar + to Python modules for example. +
+ ++ When saving a working layout, the copies are stored in the layout file too. + This feature can be disabled in a per-library basis in the library declaration + files (only available for static libraries). See the description of the + "replicate" attribute below. Note that when you use this feature, you can + only restore the entire layout, if you have these libraries installed. +
+ ++ By default, library declaration files are called "klayout.lib" and are looked up in + all places of the KLayout search path - this includes the home folder, the technology + folders and the package folders. You can override this mechanism by setting the + "KLAYOUT_LIB" environment variable to a specific file. In that case, only this + file is loaded. +
+ ++ The format of the library declaration file is "KLayout expressions". This means: function + calls need to be with round brackets and expressions are separated + by ";". For more information about expressions, see . +
+ ++ Two functions are available: "define" and "include". These are used to build + the declaration files. +
+ +Usage:
+ +include(path);+ +
Description:
+ ++ Includes the lib file given by the path. The path is + resolved relative to the current lib file. +
+ +Usage:
+ +define(name, path [, options]); +define(path [, options]);+ +
Description:
+ ++ Defines a library. In the path-only version, the library name + is taken from the layout file's LIBNAME record (GDS) or the + file name. In the name/path version, "name" is the name the + library is registered under. +
+ ++ The path is resolved relative to the current lib file. + If you want to include an environment variable, use the "env" expression + function: +
+ +define("A", env("HOME") + "/mylibs/a.gds");
+
+ + Note that the order of library definitions matters. Dependencies + need to be defined already when a library is loaded. For example + if a library "B" uses components from library "A", the order needs + to be: +
+ +define("A", "a.gds");
+define("B", "b.gds");
+
+ + The following options are available: +
+ +technology: binds a library to a technology - i.e. it is only + available in the editor when that technology is selected:
+ +define("A", "a.gds", technology="SG13A");
+
+ + By default, libraries are not bound to a technology, except if + the library file is loaded in the context of a technology (i.e. + sits in a technology folder). You can explicitly enable a library + for all technologies using: +
+ +define("A", "a.gds", technology="*");
+
+ technologies: binds a library to several technologies. The + argument is a list:
+ +define("A", "a.gds", technologies=["SG13A","GF180"]);
+
+ replicate: this flag indicates that components of the library + are replicated in the layout files using a library element. + This allows loading that file without actually having the library. + However, it comes with a size overhead, that can be avoided + by skipping this replication: +
+ +define("A", "a.gds", replicate=false);
+
+ By default, replication is enabled.
+ +