System-Level Design - Semantics Project
The design of future complex systems will require methods and tools
that can span a range of abstractions. In particular the specification
at several levels deserves attention. In this research we focus on the
syntax and semantic models for system-level design. We divide the
problem into parts: abstract syntax, syntactic transformations,
concrete syntaxes, type systems, and semantic models. The objective is
to achieve agreement within these parts to promote interoperatbility of
tools and a deeper understanding of design methodologies.
Rather than a single monolithic specification, we plan to produce a set
of specifications that cover orthogonal properties of specification
languages. This results in a pragmatic approach to interoperability.
For interoperability an essential factor is that the underlying concepts
are understood and designed with various degrees of compatibility in
We separate the problem into five parts, where we will address the
research issues in (roughly) this order:
- Abstract syntax. An abstract syntax defines how a design can
be decomposed into interconnected components. The abstract syntax is
given in the mathematical language of sets and relations.
- Syntactic Transformations. A set of operations transform one
design into another. They can be used to model higher-order functions
and object-oriented inheritance in an abstract way.
- Concrete syntax. A concrete syntax defines how a design and
transformations on a design can be represented and manipulated in a
persistent, computer-usable format. Examples are XML with associated
DTDs, APIs, and netlist formats like EDIF or a VHDL like syntax.
- Type systems. A type system imposes constraints on the
interconnection of computation, and provides for propagation of
constraints through type inference and type resolution. We will
give an abstract specification that permits tools to define the
type systems they assume.
- Semantics. A semantics gives a meaning to an interconnection of
components. Examples can be that a connection represents a
communication between two processes or a transition between two states.
We will give a suite of semantic models applicable to component-based
Last updated 11/05/99