Oasis Format API
gets Enhanced
SANTA CRUZ,
Calif. — The Open Artwork Systems Interchange
Standard (Oasis) is still a long way from
replacing the venerable GDSII layout exchange
format, but new technology available from Oasis
Tooling Inc. may help speed the process,
according to that company.
The Oasis format
claims to provide as much as a tenfold reduction
in the size of design data compared with GDSII.
Oasis Tooling provides a C++/C application
programming interface (API) that brings Oasis
functionality to developers of tools for IC
layout and mask development. The company sells
to EDA vendors, mask shops, IDMs and IC design
teams.
President and
CEO Tom Grebinski acknowledged that Oasis is
only being used at the "bleeding edge" today. He
noted, however, that several
companies--including Texas Instruments, Intel,
IBM, Dai Nippon Printing, Toppan Photomasks,
Fujitsu and NEC--are "seriously implementing"
the emerging standard, and that EDA providers
have rolled out Oasis support.
One feature
Oasis Tooling is adding to its API is a "partial
selective" encryption technology that uses Oasis
"CBlock" records. To encrypt anything in a GDSII
file, Grebinski noted, you have to encrypt and
then decrypt the whole file. But Oasis Tooling
developed a selective encryption capability
using the compression blocks in the Oasis
format, he said. "With Oasis you don't have to
give access to the entire file," Grebinski said.
"You can encrypt and decrypt hierarchically, or
by cells or layers. If there's highly sensitive
information, you can leave it encrypted so it
can only be read by tools."
Also new is a
database optimization capability, dbPrune, that
offers Oasis computational facilities for
various design operations. It runs on top of a
database driven by some of the low-level
primitives defined in the Oasis standard. In
particular, it makes use of the format's
implicit "repetition recognition."
There are two
ways to implement Oasis, Grebinski said: modal
filtering and repetition recognition. With the
former, there's some compression compared to
GDSII, but all data is represented explicitly.
If 100,000 polygons are all the same size,
there's still one data record for each.
With repetition,
in contrast, only one polygon would need to be
specified, along with information that describes
the location of the rest of the polygons. The
dbPrune database optimizer, Grebinski said, goes
into databases and looks for repetitive data. It
then analyzes the data and decides how it can be
represented. This process can "collapse"
OpenAccess or GDSII databases by a factor of
seven to 50, he said, providing more than a 10x
speedup over OpenAccess.
Meanwhile, Oasis
Tooling is porting its C++/C API stack to the
Cell Broadband Engine processor, in a bid to
improve the speed with which EDA apps such as
design rule checking, 2-D rendering and
model-based optical proximity correction can run
on Cell-based workstations.
The gmTest
utility claims to verify the correctness of EDA
software. It includes test cases designed to
catch coding errors and incorrect methods and
operations. "These are commercial test cases
that allow the EDA suppliers and the IDMs and
foundries to work more closely together, without
having to share sensitive information,"
Grebinski said. The utility combines analysis of
computational geometry algorithms, automated
layout synthesis, geometric hashing and code
coverage.
Another utility,
ipHasher, removes proprietary layout information
from files while maintaining detected bugs that
must be shared with a software supplier.
Pricing for the
technology, offered both retail and to OEMs,
varies by volume
