
Publication No. SBC330-0HH/3
Functional Description 29
By
default,
shipped
boards
have
the
top
8
MBytes
reserved
as
boot
Flash,
and
the
Core
1
Boot
bit
in
the
Flash
Control
Register
(offset
0x0044,
see
the
Registers
section)
is
set
to
0.
If
core
1
is
required
to
boot
from
a
different
image,
then
the
core
0
boot
loader
must
include
code
to
set
the
Core
1
Boot
bit
to
ʹ
1
ʹ
before
releasing
core
1.
See
the
SBC330
software
manual
for
further
description
of
BootROM
loaders.
The
BANC
(Boot
Area
Non
Corruptible)
recovery
boot
image
area
contains
a
256 KByte
factory
‐
programmed
boot
image,
shared
by
both
processing
cores,
allowing
the
Flash
to
be
reprogrammed
if
other
boot
images
become
corrupted.
This
area
is
protected
by
hardware
and
is
not
writeable
by
the
user.
The
remainder
of
this
2
MByte
boot
image
can
be
used
to
store
BIT
results.
The
boot
Flash
is
accessed
using
Chip
Select
0
on
the
Local
Bus
Controller
of
the
MPC8641D,
and
is
configured
as
the
default
boot
location
for
the
PowerPC
reset
vector
(0xFFF0
0100).
The
boot
areas
are
mapped
into
a
16
MByte
window.
The
active
boot
image
for
Core
0
is
set
using
P10
pins
5
to
8
as
described
in
Chapter
4 •
.
The
Core
1
boot
region
is
either
the
same
as
the
Core
0
boot
region
or
is
the
same
offset
by
8
MBytes
if
the
Core
1
Alternative
Boot
bit
is
set
in
the
Flash
register.
The
Core
0
and
Core
1
boot
regions
are
linked
because
there
are
insufficient
jumpers
on
SBC330
to
make
them
completely
independent.
5.3.5 User Flash
Any
Flash
that
is
not
used
as
Boot
Flash
is
designated
as
User
Flash
and
is
intended
to
hold
user
application
code
or
data.
User
Flash
is
accessed
using
Chip
Select
CS1
on
the
Local
Bus
Controller
of
the
MPC8641D.
Chip
Select
1
is
intended
for
use
by
Processing
Core
0
and
may
be
used
to
access
all
areas
of
Flash,
as
required
when
using
a
single
‐
core
or
SMP
system.
The
8
MBytes
of
Boot
Flash
appears
at
the
top
of
the
User
Flash
area,
with
the
four
boot
images
appearing
in
their
physical
locations
(i.e.
0xEF80
0000
to
0xEFFF FFFF
mirrors
0xFF80
0000
to
0xFFFF
FFFF).
Chip
Select
1
accesses
are
unaffected
by
the
boot
‐
swap
jumper
links.
Programming
at
a
given
offset
therefore
always
stores
at
that
given
offset.
For
example,
using
CS0,
programming
at
0xFFF0
0000
may
actually
program
into
Flash
at
0xFFFD
0000
if
P10
pins
5
and
6
are
linked.
Using
CS1,
programming
0xEFF0
0000,
programs
into
Flash
at
0xEFF0
0000
(which
is
also
equivalent
to
0xFFF0
0000),
regardless
of
the
Flash
boot
link
settings.
5.3.6 Paged Flash Mode
CAUTION
This mode is only available with SBC330 boards that have 512 MByte of Flash fitted.
When
an
SBC330
is
fitted
with
512
MBytes
of
Flash,
due
to
limitations
on
the
size
of
the
processor
memory
map,
a
paged
mode
is
provided
where
the
User
Flash
area
is
divided
into
a
number
of
128
MByte
pages,
with
separate
pages
selectable
for
Chip
Select
1
(CS1).
This
mode
is
controlled
by
two
Flash
page
bits
in
the
Flash
Control
Register.
Paged
mode
is
disabled
by
default,
with
the
effect
that
CS1
points
to
the
top
page.