Programming 55
set
high
(1),
the
Global
Interrupt
Enable
bit
will
automatically
be
cleared
as
this
register
(LISR)
is
being
read.
This
bit
is
read
and
write
accessible
with
this
register
and
thus
allows
a
single
read
‐
modify
‐
write
operation
to
service
the
local
interrupts.
Bit
13:
Local
Memory
Parity
Error
‐
When
this
bit
is
high
(1),
one
or
more
parity
errors
have
been
detected
on
local
memory
accesses.
This
bit
is
latched.
Once
set,
it
must
be
cleared
by
writing
a
zero
to
this
bit
location.
Note
that
Bit
27
of
the
LCSR1
must
be
set
high
before
parity
is
active.
Also
note
that
parity
works
only
on
32
‐
bit
and
64
‐
bit
accesses.
Word
(16
‐
bit)
and
byte
(8
‐
bit)
memory
write
accesses
are
inhibited.
Bit
12:
Memory
Write
Inhibited
‐
When
this
bit
is
high
(1),
an
8
‐
bit
byte,
a
16
‐
bit
word,
or
a
24
‐
bit
write
to
local
memory
was
attempted
and
inhibited
while
the
board
was
in
the
parity
enabled
mode.
This
bit
is
latched.
Once
set,
it
must
be
cleared
by
writing
a
zero
to
this
bit
location.
Bit
11:
Latched
Sync
Loss
–
When
this
bit
is
high
(1),
the
receiver
circuit
has
lost
synchronization
with
the
incoming
signal
one
or
more
times.
This
bit
is
latched.
Once
set,
it
must
be
cleared
by
writing
a
zero
to
this
bit
location.
The
assertion
of
the
Latched
Sync
Loss
usually
indicates
the
receiver
link
was
or
is
disconnected,
either
intentionally
or
unintentionally,
and
data
may
have
been
lost.
This
event
will
also
occur
if
the
upstream
node
tied
to
the
receiver
is
powered
off
or
is
disabled.
Bit
10:
RX
FIFO
Full
–
When
this
bit
is
high
(1),
the
RX
FIFO
has
been
full
one
or
more
times.
This
bit
is
latched.
Once
set,
it
must
be
cleared
by
writing
a
zero
to
this
bit
location.
This
is
a
fault
condition
and
data
may
have
been
lost.
NOTE
This condition should not occur during normal operation. Bit 10 is for diagnostic purposes only.
Bit
09
:
RX
FIFO
Almost
Full
–
When
this
bit
is
high
(1),
the
RX
FIFO
has
been
almost
full
one
or
more
times.
This
bit
is
latched.
Once
set,
it
must
be
cleared
by
writing
a
zero
to
this
bit
location.
The
assertion
of
the
RX
FIFO
Almost
Full
bit
indicates
the
receiver
circuit
is
operating
at
maximum
capacity.
If
it
does
occur,
the
PCI
bus
master
should
temporarily
suspend
all
write
and
read
operations
to
the
board.
Bit
08:
Bad
Data
–
When
this
bit
is
high
(1),
the
receiver
circuit
has
detected
invalid
data
one
or
more
times.
This
bit
is
latched.
Once
set,
it
must
be
cleared
by
writing
a
zero
to
this
bit
location.