3 research outputs found
Compositional approach to design of digital circuits
PhD ThesisIn this work we explore compositional methods for design of digital circuits with
the aim of improving existing methodoligies for desigh reuse. We address compositionality
techniques looking from both structural and behavioural perspectives.
First we consider the existing method of handshake circuit optimisation via control
path resynthesis using Petri nets, an approach using structural composition. In
that approach labelled Petri net parallel composition plays an important role and
we introduce an improvement to the parallel composition algorithm, reducing the
number of redundant places in the resulting Petri net representations. The proposed
algorithm applies to labelled Petri nets in general and can be applied outside of the
handshake circuit optimisation use case.
Next we look at the conditional partial order graph (CPOG) formalism, an approach
that allows for a convenient representation of systems consisting of multiple
alternative system behaviours, a phenomenon we call behavioural composition. We
generalise the notion of CPOG and identify an algebraic structure on a more general
notion of parameterised graph. This allows us to do equivalence-preserving manipulation
of graphs in symbolic form, which simplifies specification and reasoning about
systems defined in this way, as displayed by two case studies.
As a third contribution we build upon the previous work of CPOG synthesis used
to generate binary encoding of microcontroller instruction sets and design the corresponding
instruction decoder logic. The proposed CPOG synthesis technique solves
the optimisation problem for the general case, reducing it to Boolean satisfiability
problem and uses existing SAT solving tools to obtain the result.This work was
supported by a studentship from Newcastle University EECE school, EPSRC grant
EP/G037809/1 (VERDAD) and EPSRC grant EP/K001698/1 (UNCOVER).
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