The translation of processes into circuits

A process is a pair 〈 A, X 〉 in which A is a set of symbols (the alphabet) and X is a non-empty prefix-closed subset of A* (the trace set). A process may be viewed as the specification of a mechanism: -symbols correspond to events that may occur. -traces correspond to sequences of events that may be observed when the mechanism is in operation. In this paper we show how for a certain class of processes circuits can be derived that behave as prescribed by these processes. The circuits are delay-insensitive in the sense that their behaviour does not depend on delays in wires and switching elements. Events may be initiated by a mechanism (active events) or by the environment of the mechanism (passive events). It is shown how active events can be transformed into passive events, and vice versa. We show how the composition of processes corresponds to the composition of circuits

A compositional proof theory for real-time distributed message passing

A compositional proof system is given for an OCCAM-like real-time programming language for distributed computing with communication via synchronous message passing. This proof system is based on specifications of processes which are independent of the program text of these processes. These specifications state (1) the assumptions of a process about the behaviour of its environment, and (2) the commitments of that process towards that environment provided these assumptions are met. The proof system is sound w.r.t a denotational semantics which incorporates assumptions regarding actions of the environment, thereby closely approximating the assumption/commitment style of reasoning on which the proof system is based. Concurrency is modelled as "maximal parallelism"; that is, if a process can proceed it will do so immediately. A process only waits when no local action is possible and no partner is available for communication. This maximality property is imposed on the domain of interpretation of assertions by postulating it as separate axiom. The timing behaviour of a system is expressed from the viewpoint of a global external observer, so there is a global notion of time. Time is not necessarily discrete

Proceedings of the joint SRC/University of Newcastle upon Tyne workshop on VLSI: machine architecture and very high level languages

SIGLELD:8724.9(156) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A recursive (VLSI) computer architecture

SIGLELD:8724.9(161) / BLDSC - British Library Document Supply CentreGBUnited Kingdo