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GRETA: a tool concept for validation and verification of signal based systems


Andreas Amström , Camila Grozs , Andreas Gullemot

Research group:

Publication Type:

Report - MRTC




The main part of the software in the Ericsson AXE telecommunication system is based on an event based real time language called PLEX. In this master thesis the main subjects are to add the possibility of abstraction and analysis of systems written in PLEX. GRETA (GRaphical Extractor and Time Analyzer) enables the programmer to view and explore the system graphically and browse the system on different abstraction levels. The graph shows time data for signals and code-items. It enables programmers to find unoptimized parts, dead ends, loops and to understand the behavior of the system on signal level.<br> The prototype applies graphical abstraction on systems written in PLEX. GRETA is structured in three parts, a facts finder, a structure finder and a graph finder. The Facts Finder (code information extraction part) extracts necessary information from PLEX code and compiler (not implemented). The Structure Finder (implemented in Prolog) uses output from the Facts Finder (output is a well specified data file). The program is able to capture the signaling connections between the function blocks and the code-items in the system. The Graph Finder (implemented in Java) uses the structures created by the Structure Finder and displays all connections graphically.


author = {Andreas Amstr{\"o}m and Camila Grozs and Andreas Gullemot},
title = {GRETA: a tool concept for validation and verification of signal based systems},
number = {ISSN 1404-3041 ISRN MDH-MRTC-16/2000-1-SE},
month = {February},
year = {2000},
url = {}