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The purpose of these tools is to make delay insensitive circuits
accessible to non-specialists, and to lighten the work of
experienced designers. The circuit synthesis tool
syndi allows designers to concentrate on the
creative aspects while having the routine aspects handled
automatically, and the analysis tool diana allows
many kinds of design errors to be detected easily before they
become expensive to correct. Although other asynchronous CAD
tools exist, few if any address themselves to DI circuits.
Unlike other asynchronous design styles and protocols, delay insensitive design disallows any assumptions about the relative ordering of causally unrelated events. Although reputed to be difficult, it is actually the easiest of all asynchronous design methods, because it dispenses with the inherent difficulties of timing variations due to the fabrication process or layout.
Moreover, DI circuits are (IMHO) the only kind with a satisfactory theoretical model to argue convincingly that a circuit will work as intended before committing it to silicon, in effect by considering every possible combination of propagation delays. If you have only one shot at an expensive production run or a short term marketing window, a delay insensitive design is your best bet.
A short non-technical overview of the theory behind the tools
and their effectiveness is in this four-page extended abstract. Some material
illustrating their capabilities is in these slides from a seminar presentation.
Detailed information on how to use them can be obtained by looking at
the diana reference manual or
downloading it in PDF format, and similarly
for the syndi online reference,
also available in PDF. This page will be
updated with a tutorial manual and more examples as they become
available.
The tools themselves can be freely downloaded under the terms of
the GNU General
Public License in ditools-0.2.0.tar.gz, that
includes documentation and pre-compiled virtual code
binaries. (This release is somewhat improved on the original
from June 2003.) They will require avram in order to
run, which is packaged separately. The
AT&T graph visualization
tools are also strongly recommended.