Publication No. SBC330-0HH/3
Functional Description 25
5.2.1 PowerPC processing cores
The
MPC8641D
contains
two
e600
high
‐
performance,
32
‐
bit,
superscalar,
PowerPC
processing
cores,
as
used
in
the
MPC7448
processor,
clocked
at
up
to
1.33
GHz.
Each
core
includes:
• 32
‐
KByte
Level
1
instruction
and
data
caches
• 1
‐
MByte
Level
2
backside
cache
with
ECC
• 36
‐
bit
physical
addressing
• AltiVec
Vector
Unit
• Enhanced
branch
prediction
capabilities
• MMU
and
integral
FPU
• The
e600
processing
core
implements
a
fully
static
architecture
and
offers
sophisticated
power
management
capabilities.
The
SBC330
is
offered
in
three
speeds.
However,
users
can
configure
the
speed
of
the
SBC330
in
software
and
request
firmware
that
supports
intermediate
speeds.
The
SBC330
feeds
a
66.6
MHz
clock
into
the
8641D
processor,
and
registers
in
the
FPGA
allow
a
user
to
select
the
multipliers
that
are
available
within
the
8641D
to
achieve
different
speeds.
Current
firmware
supports
up
to
MPX
Bus
(Platform)/Core
speed
options.
Contact
your
nearest
GE
Intelligent
Platforms
Sales
Office
or
Agent
for
more
information.
5.2.2 Dual Processing Core operation
The
MPC8641D
contains
two
processing
cores.
Following
reset,
processing
core
1
is
prevented
from
accessing
the
MPX
bus
until
it
is
enabled
by
core
0.
The
two
processing
cores
can
run
two
different
operating
systems
or
two
separate
instances
of
the
same
operating
system.
This
is
called
Asymmetric
Multi
‐
Processing
(AMP)
mode.
It
is
aided
by
the
Low
Memory
Offset
mode
of
the
MPC8641D,
which
applies
a
256
MByte
address
offset
to
accesses
by
Core
1
to
the
bottom
of
RAM
(addresses
0x000
0000
to
0x1000
0000
are
offset
to
0x1000
0000
to
0x2000
0000).
This
allows
both
processing
cores
to
maintain
separate
stacks
and
private
memory
without
any
software
intervention.
The
two
processor
cores
are
also
able
to
run
a
single
operating
system,
with
tasks
divided
between
them.
This
is
called
Symmetric
Multi
‐
Processing
(SMP)
mode.
In
this
mode,
the
Low
Memory
Offset
feature
is
not
desirable
as
both
processors
need
to
share
the
same
memory
space.
Table 5-1 Processor Core Frequency Options
Core Frequency (MHz)
MPX Bus Frequency (MHz)
1000
400
1333
533
1500
600
User
User