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BEHAVIOURAL SIMULATION OF MIXED ANALOGUE/DIGITAL CIRCUITS
4.6 Conclusions.
be
to
developed
been
has
to enable an object-oriented approach
A hierarchy of classes
implement
language
these
The
C++
to
was
selected
for
mixed-signal simulation.
used
designof the classhierarchy.
influenced
decision
the
This
classes.
base
from
derived
be
design
to
class.
a
single
requires all classes
A pure object-oriented
design
imposes
C++
to
type-checking
ensure
strong
This approach was not used since
in
inefficiencies
base
to
Forcing
class
result
would
a
common
use
objects
all
consistency.
from
derived
Instead,
were
objects
all
principal
advantages.
significant
without offering
base
that
and
respectively.
signals
models
generic
represent
two
classes
one of
The class hierarchies were designed using software engineering methods and a related
designed
be
to
This
the
suchthat the correlation and cohesion
classes
CASE tool.
enabled
betweenclasseswas optimised.
hierarchy
branch
the
top
of
class
are abstract and are never
of each
The classesnear the
descended,
hierarchies
As
directly.
the
form
specialisations
are
are
class
to
objects
used
form
information
to
derived
they
signal
or
sufficient
contain
to
the
classes
until
added
its
inherits
derived
Each
the
parent
attributesand operationsof
all of
class
model objects.
for
This
the
example,an accuratemodel of a
creation of new models:
simplifies
classes.
by
from
ideal
be
an
amplifier class adding extra
particular type of amplifier could created
The
typically
the
of
a
child
operations.
creation
class
of
some
redefining
and
attributes
how
its
behaviour
is
different
from
define
its
few
lines
to
parent.
of code
only requiresa
This approachmakes the processof writing new models more efficient and less errorpronethan conventionaltechniques.
Object-orientedmodels have been createdfor a variety of digital, analogue and mixedsignal componentsusing the methodsdevelopedin Chapter3. The models were evaluated
using the Windows-basedsimulation environment(POISE) describedin Appendix A by
comparingthe results againstthe observedbehaviour of physical circuits and the output
of commercialsimulators.
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