A Graph Rewriting Approach for Transformational Design of Digital Systems

Transformational design integrates design and verification. It combines “correctness by construction” and design creativity by the use of pre-proven behaviour preserving transformations as design steps. The formal aspects of this methodology are hidden in the transformations. A constraint is the availability of a design representation with a compositional formal semantics. Graph representations are useful design representations because of their visualisation of design information. In this paper graph rewriting theory, as developed in the last twenty years in mathematics, is shown to be a useful basis for a formal framework for transformational design. The semantic aspects of graphs which are no part of graph rewriting theory are included by the use of attributed graphs. The used attribute algebra, table algebra, is a relation algebra derived from database theory. The combination of graph rewriting, table algebra and transformational design is new

Mission 2 Solution: Requirements Engineering Education as a Central Theme in the BIT Programme

Design of integrated business-IT solutions is the main theme in the Business Information Technology programme (BIT) at the University of Twente. Our mission is to teach students to design solutions that are needed instead of solutions that are asked for. This makes requirements engineering an essential part of our education in business-IT alignment. Integration of requirements engineering (RE) in several courses is combined with challenging the students by authentic cases, taken from business practice, in which they have to apply theory and train their competences. This combination results in reflection as well as in RE experience and insight in the importance of requirements analysis. \ud In this position paper we outline how RE is integrated in the BIT programme and we discuss the project course BIT Ltd in more detail

The order relation of recursively defined Sil-1 Nodes As part of a denotational semantics

The semantics of the elements of SIL-1 descriptions is a combination of an order relation and a data relation on the access points involved. This semantics is described in the SIL-1 Language Report. To determine the order relation on the access points of recursively defined nodes a formal definition of this semantics is needed. In this paper the order part of a denotational semantics for SIL is presented. It is shown that the order relations of recursive nodes are well defined and uniquely determined by this formal semantics. Moreover it is discussed how the orders of recursive nodes can be derived. The order relation of recursively defined SIL-1 nodes as part of a denotational semantics 1 Table of Contents Abstract....................................................................................................................... .......... 0 Table of Contents .................................................................................................................. 1 1. ..

Transformational Design Of Digital Systems Related To Graph Rewriting

. For high-level synthesis transformational design is a promising design methodology which combines correctness by construction and interactive design. In this design methodology the design steps are behaviour preserving transformations of one design representation into another. Because of the importance of visualisation of design-information several kinds of graphs are used as design representations. Transformational design based on graph representation is closely related to rewriting of (sub)graphs. In this paper the formal aspects of transformational design are related to graph rewriting theory. It is shown how a formal framework for transformational design can benefit from graph rewriting theory. Especially preconditions for the application of transformation rules can be based on generally formulated preconditions from graph rewriting theory. Moreover a general graph concept unifies graph representations and a formal framework for transformational design based on this general graph..

Transformational Design of Digital Systems Based on Graph Rewriting

Transformational design integrates design and verification. It combines "correctness by construction " and design creativity by the use of preproven behaviour preserving transformations as design steps. Transformational design is a formal design methodology in which formal aspects are hidden for the designer. Formal aspects of transformational design as a methodology for high-level synthesis, are discussed in this paper. Moreover graph rewriting theory is shown to be useful as a formal framework for transformational design. Transformations are defined as graph rewritings. Graph rewriting theory does not cover semantic aspects of graphs, which are useful as design representations because they visualise design information. A compositional formal semantics of design representations is essential in transformational design in order to prove the correctness of the transformations. This paper presents an extension of graph rewriting to attributed graphs as a suitable way to include semantical..

SIL Transformations on Sequence Edges

Introduction In this note a number of transformations on SIL graphs is described. Most emphasis will be on the transformations in which sequence edges play a crucial role. For a better understanding of the transformations and in order to be able to prove the correctness of the transformations, some attention will be given to the formal semantical model of SIL which is currently being developed. Notice however that the formal semantical model of SIL is still in its pre-development stage and only part of the available information is used. The informal semantics of SIL are explained in #Klo-91#. This note is set up in the following way. First we will explain the formal semantical model with emphasis on modelling behaviour and order, as far this is necessary for proving the transformations. The semantical components which constitute a SIL-graph are de#ned together with the composition rules. Thereafter the division of a SIL-graph in transformation blocks is explained. These trans