58 SBC330 3U VPX Single Board Computer
Publication No. SBC330-0HH/3
6.9 Miscellaneous Functions Register
This
register
provides
a
list
of
lesser
‐
used
options
for
board
operation,
mainly
concerned
with
the
operation
of
the
PLX
PEX8518
and
PEX8114
PCIe
devices.
It
defaults
to
a
value
that
is
partially
set
by
jumpers.
6.9.1 AMP/SMP mode
In
Symmetric
Multiprocessing
(SMP)
mode,
both
cores
boot
from
the
same
image
and
run
the
same
OS.
In
Asymmetric
Multiprocessing
(AMP)
mode,
each
core
can
run
separate
operating
systems
or
it
can
run
the
same
OS
and
operate
in
a
loosely
coupled
manner.
Flash
access
is
different
between
SMP
and
AMP,
and
in
SMP
the
processor
adds
256
MByte
offsets
to
core
1
addresses
(this
may
be
overridden
‐
details
will
be
added
when
SMP
software
is
running).
See
Section
4.4.2
regarding
AMP/SMP
mode
selection.
6.9.2 PEX8518 mode
The
PEX8518
Switch
device
defaults
to
a
mode
selected
by
strapping
resistors.
This
mode
can
be
overridden
by
the
CPLD.
Swapping
the
mode
allows
a
blank
SBC330
to
be
Flash
‐
programmed
over
PCIe
from
another
host
during
production.
Chip
Select
CS2
Offset
0x0028
Reset
value
0x0096
LAD Bit
Reg Bit
R/W
Description
Reset Value
15
0
R/W
AMP or SMP mode
0 = AMP mode (default, P12 pins 1 & 2 not linked)
1 = SMP mode
0
14 & 13
1 & 2
R/W
PEX8518_MODE(0:1)
00 = Reserved/Invalid
01 = Dual Host mode
10 = Intelligent Adapter
11 = Transparent mode (default)
1
12
3
R/W
PCIe Spread Spectrum Clocking control
0 = Off (default)
1 = On
0
11
4
R/W
PEX SROM write protection
0 = Off
1 = On (default)
1
10
5
R/W
PEX8114 SROM Presence detect
0 = Present
1 = Disabled (default)
1
9
6
R/W
PEX8518 SROM Presence detect
0 = Present
1 = Disabled (default)
1
8
7
R/W
I
2
C Boot EEPROM Write Protect
0 = Write enabled
1 = Write protected (default)
1