The Assemble Button: Layout File Merge Tool Panel

The Layout File Merge Tool, brought up with the Assemble button in the Convert Menu, will extract cell hierarchies from one or more layout files, optionally perform some processing, then add the hierarchies to a single output file. It is essentially a graphical front-end for the !assemble command. The tool is intended to be highly flexible. Potential applications include building up reticles for mask generation or combining design output from different development groups into a single file.

Similar operations can be performed by use of reference cells.

The supported layout file formats for input and output are GDSII, CGX, OASIS, and CIF. The file format is specified when writing, and is determined automatically when reading. Any combination of these formats can be used for input and output.

The data read from the input files can be processed in various ways before writing to output. Some of these operations are sketched below.

• The layers can be filtered, to exclude certain layers, accept only certain layers, or to map certain layers to another layer. For GDSII and OASIS, the ``layer'' is actually a layer number/datatype number combination. Specification of a layer includes wildcarding of the layer or datatype number.

• The names of cells can be modified to add or replace a prefix and/or suffix.

• The data can be transformed by scaling, rotation, translation, and mirroring before placement in the output.

• The data can be filtered to objects that overlay a rectangular window, and may be clipped to the window.

• The hierarchy can be flattened before placement.

• Empty cells can be filtered out of the output.

Any combination of these processing operations can be specified.

The processed hierarchies from the specified input layout files are generally placed in a new top-level cell created in the output file. The user can choose the name of this cell, and if no name is given, no new top-level cell will be created, and the data from each input will simply be concatenated in the output.

During the merge, the tool remembers tha names of all cells seen, and will automatically change the names of cells that would clash in the combined file. Notification of the change will be written to the log file, which is produced during a run. The logfile is named ``assemble.log'' and is produced in the current directory.