Operational Semantics for Hardware Description

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Operational Semantics for Hardware Description
Facilitator Professor S. Arun Kumar Department
of Computer Science Email sak_at_cse.iitd.ernet.in
Presented by Abhishek Banerjee Department of
Computer Science Entry 2006CS10151 Email
cs1060151_at_cse.iitd.ernet.in
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Introduction

• Conventional Programming Languages Clearly
  defined semantics.
• Definition of some mathematical primitives and
  constructs and mapping from the notational to the
  denotational level.
• Enables us to furnish a formal proof of
  correctness for the programs we write.

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Introduction (Contd.)

• Hardware Description Languages (HDLs)
  Representation of behaviour and functionality.
• Current Implementations Unclear semantics,
  undefined mathematical base.
• As a result, it is difficult to furnish a formal
  proof of correctness for our design and its
  corresponding interpretation. Verification
  becomes a problem.

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Objectives

• Study existing research in the field of process
  calculi with reference to communication and
  other such areas.
• Apply this research to build a similar calculus
  for a hardware descriptive language.
• Build a software implementation for this
  calculus.
• Study the semantic relation and attempt to
  compare multiple implementations of the same
  behaviour.

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Novelty

• Existing approaches to the problem use higher
  order temporal logic, the Petri Net approach,
  Boyer-Moore logic etc.
• We plan to use a process calculus to model the
  problem, which has been well documented in other
  applications (communication).
• A process calculus has techniques which allow
  easier reasoning of processes.

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Approach

• A Hardware System A Concurrent System
• Process Calculus A possible implementation of a
  concurrent system.
• We plan to model our HDL on a process calculus
  very similar to the one already being used to
  study communication.
• In this calculus, behaviour and implementation
  become simple terms, making it easier to argue
  their correctness.

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An Example on Concurrency

• The Dining Philosophers problem.
• Illustrates deadlock and resource starvation.
• An effective model to study concurrency.

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Approach (Contd.)

• After modeling the HDL as a process calculus, we
  are in a position to study the behaviour of its
  semantic function.
• Compare various implementations of the same
  behaviour based on certain design parameters.
• Process calculi have an effective tool for doing
  such research Bisimulations.

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Timeline

• Tasks
• A Study existing research on process calculi.
• B Build a new calculus for an HDL and make a
  software implementation for the same.
• C Study the semantic function and compare
  implementations based on design parameters.
• D Testing and report.

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Budget
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References to be Used

• Milner R, Communication and Concurrency,
  Prentice-Hall International,1989
• W Van Fokkink, Introduction to Process Algebra,
  EATCS Springer-Verlag 2000
• M. Hennessy, Algebraic Theory of Processes, MIT
  Press, 1991
• Milner R, Communicating and Mobile Systems The
  Pi-Calculus, Cambridge University Press, 1999

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