Formalizing, Validating, and Verifying Real-Time System Requirements with Reacto and VHDL
Abstract
We develop a methodology for formalizing, verifying, and validating the requirements specification of real-time systems based on a graphical and formal hierarchical Finite State Machine (FSM) language Reacto. We define a means to quantify time and express real-time constraints in Reacto and a transformation from Reacto to the Very High Speed Integrated Circuit (VHSIC) hardware Description Language (VHDL). Reacto's high level abstractions, graphical nature, and theorem prover produce efficient, accurate, and easily understood specifications. We use VHDL's event driven simulation capability, concurrency, and temporal operators to thoroughly examine temporal dependencies between the state machine transitions, and to increase simulation power by simulating multiple communicating FSMs. We apply the methodology to two example problems, a cruise control, and a lift (elevator) controller. We verify that the state machine specification is consistent and validate the specification using executable simulations in both Reacto and VHDL. We evaluate the methodology against criteria for real-time specification languages and conclude that Reacto and VHDL complement each other well. Together, they abstract the real world well, are clearly understood, verify that the specification and implementation are consistent, axe easy to modify, allow requirements tracing, and finally, support specification of concurrency and timing constraints.... Requirements Analysis, Real Time, System Specification, Reacto, VHDL, Software
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 15, 1992
- Accession Number
- ADA259224
Entities
People
- Frank C. Young
Organizations
- Air Force Institute of Technology