70 SBC330 3U VPX Single Board Computer
Publication No. SBC330-0HH/3
6.19 Configuration Resistors Register
SBC330
has
a
resistor
‐
defined
configuration
for
initial
Platform
and
Processor
Core
speed.
The
Platform
and
Processor
Core
speed
can
be
changed
via
the
Sticky
registers
for
the
Platform
and
Core
Multipliers,
which
take
effect
after
a
reboot
so
long
as
power
is
maintained.
Three
signal
lines
to
the
FPGA
are
pulled
high
or
low
by
resistors
giving
eight
hardware
defined
speed
configuration
options
from
power
up.
Table
6
‐
5
shows
the
value
read
in
the
register
versus
the
SBC330
speed
configuration
set
up.
NOTE
The highlighted rows in the table indicate the default speeds that align to SBC330 Product Codes.
The
code
‘000’
in
the
FPGA
interprets
as
PLATFORM_MULTIPLIER
=
6x
and
CORE_MULTIPLIER
=
2.5x.
The
SBC330
system
clock
is
66.66
MHz,
which
means
the
Platform
speed
is
(66.66
x
6
=
400
MHz)
and
the
Core
Speed
is
(2.5x
400
=
1000
MHz).
A
total
of
six
configuration
resistors
control
the
default
platform
and
core
speed
of
the
processor.
These
are
R570,
R569,
R571
(10K
pull
‐
ups
to
P3V3)
and
R215,
R244,
R245
(1K
pull
‐
downs
to
ground).
R570
&
R215
control
CFG(0),
R569
&
R244
control
CFG(1),
and
R571
&
R245
control
CFG(2).
Chip
Select
CS2
Offset
0x00AC
LAD Bit
Reg Bit
R/W
Description
Reset Value
15 to 13
0 to 2
R
Straight binary of resistor pull-downs and
pull-ups on signals CPLD_DEBUG(0:2)
Depends on
jumper
settings
Table 6-5 Register to Speed Mapping
SYSCLK
Frequency
(MHz)
SYSCLK to
Platform Clock
Multiplier
Platform
Frequency
(MHz)
Platform
to Core
Multiplier
Core
Frequency
(MHz)
CFG_SYS
_PLL[0:3]
CFG_CORE
_PLL[0:4]
CFG_
PLATFORM
_FREQ
Resistor
CFG binary
value
CPLD_CFG
[0..2]
66.66
2
133.3
2.0
266
0
None
66.66
3
200
2.5
500
0
Implement
66.66
4
266.6
2.5
665
0
0 001
b
66.66
5
333
2.5
833
0
1 010
b
66.66
6
400
2.5
1000
0110
b
01100
b
0
2 000
b
66.66
8
533.3
2.5
1333
1000
b
01100
b
1
3 011
b
66.66
9
600
2.0
1200
1001
b
01000
b
1
4 100
b
66.66
6
400
3.0
1200
0110
b
10000
b
1
5 101
b
66.66
6
400
3.5
1400
0110
b
11100
b
1
6 110
b
66.66
9
600
2.5
1500
1001
b
01100
b
1
7 111
b