In the design of integrated circuits, the most popular format for interchange is the Calma GDS II stream format (GDS II is a trademark of Calma Company, a wholly . Portions of the GDSII Stream Format Manual, Documentation No. B97E, Feb. , reprinted with permission of Cadence Design Systems, Inc., River. GDS II is a database file format which is the de facto industry standard for . The GDSII or Stream file format stores its information in records.
|Published (Last):||12 October 2007|
|PDF File Size:||13.1 Mb|
|ePub File Size:||10.61 Mb|
|Price:||Free* [*Free Regsitration Required]|
This marks the beginning of an array reference element sream array of cells. Required for Filtered format, and present only in Filtered Stream files.
The current design in memory is modified as well with formatt save operation. This method will allow an unlimited number of polygon points. The decimal point of the binary mantissa is just to fogmat left of bit 8. The first two words, or four bytes, are called the “Record Header” A record can be as small as 4 bytes long. GDS II files can be read as normal files or gzip compressed files without an external decompresser. This informationis used only when reading the data into a new library.
Bit 14 specifies external data also referred to as “exterior” data. The reason for this is as follows. These records are built up of 16 bit words. GDSII limitations can affect how you design your layout. Bits 10 and 11, taken together as a binary number, specify the font. Note Because the GDSII stream is a block-structured binary file, it can easily be corrupted when transferring the file from one system to another.
Same basic thing as a two byte integer, but with four bytes. Fortunately, the way the database was created enabled users to extend many of the dejure limitations while maintaining defacto compatibility with the actual architectural underpinnings.
Welcome to buchanan1.net
Attribute numbers and are reserved for the user integer and user string properties, which existed prior to Release 3.
End of library token An example of a common record gdsij see below for record descriptions follows: A polygon exceeding this limit will formxt split by default. This is required for Filtered format, and is present only in a Filtered Stream file.
Contains four bytes which specify in database units the extension of a path outline beyond the first point of the path.
Two-byet signed integer 2. The name of font 0 starts the record, followed by the remaining 3 fonts. See Importing a Layout for more information.
CHAPTER 1 GDSII format
This should be selected for the following conditions:. This marks the beginning of a node.
Objects contained in a GDS II file are grouped by assigning numerical attributes to them including “layer number”, “datatype” or “texttype”. It is a binary file format representing planar geometric shapes, text labels, and other information about the layout in hierarchical form. The data can be used to reconstruct all or part streeam the artwork to be used in sharing layouts, transferring artwork between different tools, or creating photo masks.
The hex numbers are read backwards, from right to left, strean each pair of digits representing a byte.
All About Calma’s GDSII Stream File Format
Since the mantssa is shifted four bits at a time, it is possible for the left three bits of a normalized mantissa to be zero. Exactly 3 pairs 1: Order the complete book from SPIE. All other bits are currently unused and must be cleared to 0. Retrieved from ” https: Bit 15 rightmost specifies template data. Neither the number of columns nor the number of rows may exceed 32, decimal and both are positive. Bits 0 through 9 are reserved for future use and must be cleared.
Actually, the data type seems redundant, since each record type has only one valid data type.