Stream/OASIS-to-OpenAccess Layer Map File

This topic discusses the supportfor high capacity loading and saving of GDSII and SEMI^® Open Artwork System Interchange Standard (OASIS™) stream files.

The layer map file maps stream (GDSII or OASIS) layer and data type numbers to OpenAccess layer and purpose names. The file format is the same as the layer map file format used with the OpenAccess stream translators (strm2oa and oa2strm), with some added optional arguments mentioned in the syntax below.

oaLayer oaPurpose strmLayer strmDataType [oaMaterial] [oaMaskNumber] [direction]

oaMaterial specifies the material type as metal, cut or other.
oaMaskNumber specifies the fabrication order.
direction specifies the preferred direction as horizontal or vertical.

The Stream/OASIS-to-OpenAccess layer map file is required to run read_stream and write_stream and is specified using the -layer_map argument.

Each complete line in the layer map file must be unique. For read_stream, you can specify multiple stream (strmLayer/strmDataType) entries for the same LPP (oaLayer/oaPurpose) entry. For write_stream, you can specify multiple LPP entries for the same stream entry.

If you use read_stream to detect vias (-detect_vias), for optimal performance you should do the following:

Specify the appropriate material types, metal and cut, for the via metal and cut layers in the oaMaterial column. Other layers can be type other.
Specify the fabrication order for the layers using ascending mask numbers in the oaMaskNumber column. For example, metal1 would be 1, via1 would be 2, metal2 would be 3, and so on.
Example of a Stream/OASIS-to-OpenAccess Layer Map File

#oaLayerName  oaPurpose  strmLayer strmDataType oaMaterial oaMaskNumber direction
PImp          drawing         13        13         PImplant   3
Metal1        drawing1        1         1          metal      6        horizontal
Via1          drawing2        2         2          cut        7
Metal2        drawing3        3         3          metal      8        vertical
Via2          drawing4        4         4          cut        9
Metal3        drawing5        5         5          metal      10
Via3          drawing6        6         6          cut        11
Metal4        drawing7        7         7          metal      12
Via4          drawing8        8         8          other      13
Metal5        drawing9        9         9          other      14

For this example, vias on Via1, Via2, and Via3 would be automatically detected by read_stream but vias on Via4 would not be detected because the oaMaterial values are not set properly for Via4 and Metal5.

Virtuoso Space-based Router Command Reference
Product Version IC23.1, September 2023