CONTENTS

KNOWLEDGE ENGINEERING: PRINCIPLES AND TECHNIQUES
Proceedings of the International Conference on Knowledge Engineering,
Principles and Techniques, KEPT2009
Cluj-Napoca (Romania), July 2–4, 2009, pp. 235–238
ALGEBRAIC MODEL FOR THE SYNCHRONOUS SR-FLIP-FLOP
BEHAVIOUR
ANCA VASILESCU (1)
Abstract. Considering the digital logic level of the computer architecture description,
the agent-based approach is applied here to cover both the digital
logic circuits specification and verification. We consider the specific structure
for both the asynchronous and synchronous SR flip-flops. We define the appropriate
specification and implementation agents for algebraic modelling the given
circuits behaviour and we formally and automatically prove the corresponding
bisimilarities between the target agents.
1. Introduction
This paper results represent the authors research area consisting in applying
formal methods for modelling the hardware components behaviour and in obtaining
an algebraic-based model for the entire computer system behaviour.
Having an algebraic-based model for a multi-agent system has the main advantage
of increasing the level of confidence and reliability on the model following the formal
methods based verification. For the specific case of a computer system, we have also
the advantage of the opportunity of removing all the possible design errors before
proceeding to the expensive component manufacturing and assembly.
In modern computer science, the process algebras are extensively used together
with the appropriate verification tools such that the combination assures both the
modelling of the computer components behaviour and the formal and/or automated
verification of the proposed models. The most used such combinations are: SCCS/CWB,
CSP/FDR2 and LOTOS/CADP [1, 8]. The SCCS as process algebra and CWB-NC
[9] as verification workbench are used here in order to study the concurrent communicating
processes involved in the computer hardware components behaviour and to
model and verify the target hardware components behaviour.
2. Preliminaries
2.1. Flip-flops. Computer memory organization. A flip-flop is a sequential
circuit, a binary cell capable of storing one bit of information. It has two outputs, one
2000 Mathematics Subject Classification. 68Q85, 68N30, 68Q60, 93C62.
Key words and phrases. bisimulation equivalence, concurrency workbench, digital circuits, flipflop,
SCCS process algebra, specification, verification.
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c○2009 Babe¸s-Bolyai University, Cluj-Napoca