FreeLists / si-list / [SI-LIST] Bad packages, core power, SSO and IBIS

["Mirmak, Michael" <michael.mirmak@xxxxxxxxx>]

As Zhiping Yang noted in an earlier message on this thread, IBIS is
indeed taking action to improve I/O SSO analysis and to start addressing
core power.

Many tools now use IBIS models for SSO analyses.  However, the IBIS Open
Forum and the wider IBIS community recognize that today IBIS does not
optimally address SSO, as the IBIS format does not explicitly describe
distributions of supply currents.  Assumptions regarding these
distributions can significantly affect the simulation results.  IBIS
does not address core power at all in any version.

The IBIS Open Forum is considering a specification change proposal to
include data for directly modeling I/O SSO. The proposal also suggests a
method for including core power behaviors.  The text of this proposal
can be found at http://www.ibis-information.org/birds/bird95.txt.

The proposal adds keywords in the traditional IBIS style to support
these longstanding modeling needs.  Additionally, please note that IBIS
4.1 already includes links to flexible behavioral languages such as
VHDL-AMS and Verilog-AMS.  These kinds of equation-based approaches
could also support the goals of SSO and core power modeling in the
longer term.  We invite SI-List members to examine and comment upon both
the proposal and the potential application of AMS to the problems.

Thoughtful members of the EDA industry understand and have here
expressed the difficulty in satisfying competing design goals when
modeling and simulating complex systems.  Attempting to simultaneously
address concerns of:

- accuracy
- simulation speed
- analysis cost
- IP protection
- compatibility with multiple simulation tools
- simplicity=20
- comprehensibility=20

in a single modeling solution is not a small task and cannot be
undertaken quickly, particularly in volunteer standards bodies.  With
regard to SSO and core power, certainly several solutions exist today
which address some of the above requirements.  However, no solution to
my knowledge addresses them all.  We hope that, through efforts like
those mentioned above, we can help the industry move toward that goal.

- Michael Mirmak
  Intel Corp.
  Chair, EIA IBIS Open Forum
  http://www.eigroup.org/ibis/
  http://www.ibis-information.org/




------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List FAQ wiki page is located at:
                http://si-list.org/wiki/wiki.pl?Si-List_FAQ

List technical documents are available at:
                http://www.si-list.org

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu