Header Block

The Header Blocks contains global directives. This must be followed by at least one Source Block, which specifies an input source.

OutFile out_file_name
(option: -o out_file_name)
This line or option is mandatory, and provides the name of the file to be used for output. This must appear before any Source Blocks. The output file name must have a recognized extension that corresponds to the format to be used. These are:

CGX	.cgx
CIF	.cif
GDSII	.gds, .str, .strm, .stream
OASIS	.oas

Only these extensions are recognized, however CGX and GDSII allow an additional .gz which will imply compression.

Basic defaults for the various output formats are as specified in the Export Control panel from the Convert Menu, or from the corresponding variables.

LogFile logfile
(option: -log logfile)
This specifies the name of a log file which is produced during the run. This will record messages, warnings, and errors that are emitted. If not given, a log will be written using a default file name, which is ``assemble.log'' in the current directory, for the !assemble command.

TopCell cellname
(option: -t cellname)
This optional line or option specifies that a new top-level cell is to be created in output. At most one TopCell can be given. This must appear before any Source Block.

If a TopCell is given, a corresponding cell definition will be created in the output file, and all cells specified in Placement Blocks (the ``placements'') will be instantiated in the new cell. Whether or not a TopCell is given, the placements will be streamed to the output file, meaning that the cell definitions needed to describe the cell and possibly its hierarchy will be added to the output file. With a TopCell given, the placements will be instantiated in the new top cell in output. Otherwise, there is no placement, and redundant Placement Blocks will be ignored. The output file can end up with multiple top-level cells, which may be desirable when creating a library.

The Header can also contain any of the Source Block or Placement Block directives below. These will be used as defaults in all blocks that follow, but can be overridden from within the blocks, or set, modified, or reset between Source Blocks.