Property-Preservation Synthesis for Unified Control- and Data-Oriented Models

1
Property-Preservation Synthesis for Unified
Control- and Data-Oriented Models
Oana Florescu, Jeroen Voeten, Henk
Corporaal o.florescu_at_tue.nl
Introduction

• Actions - need small computation time (control
  action)
• - immediate (urgent) execution
• Time-intensive computations - need considerable
  amount of execution time (multimedia algorithms)
• - finish before a deadline

Model-driven design of real-time embedded systems
1

• suitable models for real-time analysis
• correctness-preserving synthesis

Current Approach
From Model to Realisation 3
Real-Time Systems POOSL 2 Models
UML model
POOSL model
Controller()() in?input(x) computation(x)(y)
delay T out!output(y).
e-closeness e max(e1, e2)
Transition system

• Preservation of all properties up to e
• Internal computations are not observed from
  outside
• But they induce a large e
• However
• Only observable properties (of actions) are
  interesting
• Computations need to be scheduled up to a deadline

Model execution
Proposed Approach

• Intuition
• Computation split into small parts ? small e
• Mathematical support observation equivalence
• Models have the same observable properties
• Implementations of both observation equivalent
  models preserve their observable properties, but
  with different strengths

splitting computations? preemptive scheduling
By scheduling computations, P is preserved
stronger
Conclusions

• Abstract from unobservable computations which are
  scheduled to meet their deadlines
• Time-deviations are given only by observable
  actions
• Stronger preservation of observable properties

References
1 J. Huang, J. Voeten, O. Florescu, P. vd
Putten and H. Corporaal. Advances in Design and
Specification Languages for SoCs, chapter
Predictability in real-time system development.
Kluwer Academic Publishers, 2005. 2 P. vd
Putten and J. Voeten. Specification of Reactive
Hardware/Software Systems. PhD thesis, Eindhoven
University of Technology, Eindhoven NL, 1997. 3
J. Huang, J. Voeten and M. Geilen. Real-time
property preservation in approximations of timed
systems. 1st ACM IEEE International Conference
on Formal Methods and Models for Codesign
(MEMOCODE'2003), June 2003.
e max(e1, e2)
e max(e1, e2, e3, e4) lt e
Research carried out as part of the BodeRC
project.
Department of Electrical Engineering Electronic
Systems