8086
Object
Module
Formats
Version
4.8
In
the
PIC/LTL
case,
an
LSEG
is
not
allowed
to
be
in
more
than
one
group
(e.g.
defininq
two
qroups
such
as
Gr
GI(A,C,B)
and
Gr
G2(B,C,D)
in
the
same
module
is
not
legal).
Otherwise
an
LSEG
may
be
in
more
than
one
group.
The
existence
of
qroups
such
as
Gl
and
G2
is
not
sufficient
to
infer
that
A,B,C,D
all
lie
within
some
single
FRAME,
althouqh
they
miqht.
CANONIC
any
location
in
MAS
is
contained
in
exactly
4996
distinct
FRAME's;
but
one
of
these
FRAME's
can
be
distinguished
in
that
it
has
a
higher
FRA~E
NUMBER
than
any
other
FRAME.
This
distinguished
FRAME
is
called
the
canonic
FRAME
of
the
location.
Thus,
if
Foa
is
a
symbol
defininq
a
memory
location,
one
may
speak
of
the
"canonic
FRAME
of
Faa·,
or of
-FOO's
canonic
FRAME".
By
extension,
if
S
is
any
set
of
memory
locations,
then
there
exists
a
unique
FRAME
which
has
the
lowest
FRAME
NU~BER
in
the
set
of
canonic
FRAME'S
of
the
locations
in
S.
This
unique
FRAME
is
called
the
canonic
FRA~E
of
the
set
S.
Thus,
we
may
speak
of
the
canonic
FRAME
of
an
LSEG
or
of
a
Group
of
LSEG's.
SEGMENT
NAME
-
LSEG's
are
assigned
names
at
translation-time.
names
serve
only
3
purposes:
These
1)
they
playa
role
at
LINK-time
in
determininq
~h~t
LSEr,'s
are
combined
with
what
other
LSEG's.
2)
they
may
be
used
at
LOCATE-time
to
desiqnate
specific
LSEG·s.
3)
they
are
used
in
assembly
source
code
to
specify
groups.
CLASS
NAME
LSEG's
may
optionally
be
assiqned
Class
Names
at
translation-time.
Classes
define
a
partition
on
~~5EG's:
two
LSEG's
are
in
the
same
class
iff
they
have
the
same
Class
Name.
R&L
associates
no
semantics
with
specific
Class
Names;
class
semantics
are
completely
user-defined.
Examples
of
Class
Names
might
be
RED, BLUE,
GREEN
or
ROM,
RAM,
DISPLAYMEMORY.
The
uses
of
Class
Names
include
the
first
2
uses
of
Seqment
Names
above;
additionally,
Class
Names
qive
the
user
the
power
to
identify
many
LSEG's
by
a
single
handle
at
LOCATE-time.
OVERLAY
NAME
LSEG's
may
optionally
be
assiqned
an
Overlay
Name
at
translation-time
oratLINK-time.
This
name
is
specified
when
the
translator
or
LINK-So
is
invoked,
and
all
LSEG's
within
the
same
module
will
be
assiqned
the
same
Overlay
Name.
An
Overlay
Name
is
similar
to
a
Class
N~me
in
that
it
provides
a
handle
on
user-defined
equivalence
classes
of
LSEG's.
Unlike
Class
Names,
however,
Overlay
Names
have
semantics
kno~n
by
the
LOCATE-86
proqram.
(In
brief.
LSEG's
in
different
overlays
may
be
~located"
at
overlappinq
MAS
locations.)
7