1. Joint sub-comittee

We should form a joint sub-committee between
SLDL and DC-WG.  The sub-committee would have the
charter to:

- Define the general syntax and structure for the
  DC-WG constraint description language, starting with the
  Ambit donation as a strawman.

  The DC-WG constraint description language is intended to be
  entered directly by designers, although it also may be generated or
  modified by tools.  It is likely to be command-oriented, for
  compatibility with existing user input languages for constraints.
  The constraint description language is intended to be compatible
  with, but separate from, functional modeling languages (e.g., VHDL
  and Verilog) and other domain-specific modeling languages.

  DC-WG will use the general syntax of the language defined by the
  sub-committee as a basis for defining a specific syntax for each
  constraint domain.  DC-WG will deliver an English document describing
  the semantics for the constraint domain as a whole and the syntax and
  semantics for each constraint.  The target audience for the document
  includes designers, EDA tool developers, and the SLDL domain theory
  developers.

- Define a conceptual model for constraints.

  The conceptual model should describe
  - how constraints are specified, applied, refined, transformed,
    and verified throughout the design flow
  - how tradeoffs between different constraints are specified and
    considered while exploring the feasible design space
  - the differences between environment specifications, assertions
    in library models, constraints, and tool-specific directives.

  The conceptual model is an English document.  The target audience
  for the document includes designers, EDA tool developers, and
  flow/methodology developers.

- Define an information model for constraints using Express.

  The information model will be used during the development of
  the constraint description language to check for inconsistencies.
  It will also be used as a partial description of the formal semantics
  for each constraint domain, which SLDL will use as input in developing
  a set of domain theories which more completely describe the semantics
  within each domain and the semantics for interactions between domains.

2. Schedule, priorities

DC-WG is planning an aggressive schedule targeting a release of the standard
for the first phase (the timing domain) in June 1999, with an initial draft of
the constraint description language available in time for demos at DAC '99.
Given the long lead time for demo development, a complete draft of the timing
portion of the constraint description language will need to be available by the
end of March 1999. The general syntax and structure of the constraint
description language will need to be defined by early 1999, to allow time to
map the timing constraints into the syntax. The conceptual model is not a
strict pre-requisite for the other portions of the DC-WG standard, but early
versions would help to ensure consistency with the constraint taxonomy and
description language.

The information model may be released as a deliverable from DC-WG
if it proves to be sufficiently valuable.  However, this a low-priority
objective.  Completing or refining the information model should not
be a prerequisite for releasing the DC-WG standard.

3. Participation

The goal is to have the sub-committee size be sufficient to complete
the initial work in the target timeframe, and to have an adequate
reflection of the views of the SLDL and DC-WG groups as a whole.
However, more participation often slows things down, so the sub-committee
will initially be limited to 10 people with a target of 6-8 who
can actively contribute.

At least one sub-committee representative from SLDL (DC-WG) will
participate on an on-going basis in the regular DC-WG (SLDL) meetings.
Other members of SLDL (DC-WG) who are not part of the sub-committee are
also welcome to participate in the regular DC-WG (SLDL) meetings.