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182
Revision 3.1
G
7.0
This section provides information on electrical connec-
tions, absolute maximum ratings, required operating con-
ditions, DC characteristics, and AC characteristics for the
Geode GXm processor. All voltage values in the Electrical
Specifications are with respect to V
SS
unless otherwise
noted. For detailed information on the PCI bus electrical
specification refer to Chapter 4 of the PCI Bus Specifica-
tion, Revision 2.1.
Electrical Specifications
7.1
The following part numbers designate the various speeds
available. For all speeds, the V
CC2
voltage is 2.9V nominal
and the V
CC3
voltage is 3.3V nominal.
PART NUMBERS
7.2
ELECTRICAL CONNECTIONS
7.2.1
Testing and operating the GXm processor requires the
use of standard high frequency techniques to reduce par-
asitic effects. These effects can be minimized by filtering
the DC power leads with low-inductance decoupling
capacitors, using low-impedance wiring, and by utilizing
all of the V
CC2
, V
CC3
, and VSS pins.
Power/Ground Connections and Decoupling
7.2.2
Power Sequencing
the Core and I/O Voltages
With two voltages connected to the GXm processor, it is
important that the voltages come up in the correct order.
V
CC2
should come up at or before V
CC3
. There are no
additional timing requirements related to this sequence.
7.2.3
Pins designated NC (No Connection) should be left dis-
connected. Connecting an NC pin to a pull-up/-down
resistor, or an active signal could cause unexpected
results and possible circuit malfunctions.
NC-Designated Pins
7.2.4
Table 7-2 lists the input pins that are internally connected
to a 20-kohm pull-up/-down resistor. When unused, these
inputs do not require connection to an external pull-up/-
down resistor.
Pull-Up and Pull-Down Resistors
7.2.5
All inputs not used by the system designer and not listed
in Table 7-2 should be kept at either ground or V
CC3
. To
prevent possible spurious operation, connect active-high
inputs to ground through a 20-kohm (±10%) pull-down
resistor and active-low inputs to V
CC3
through a 20-kohm
(±10%) pull-up resistor.
Unused Input Pins
Table 7-1. Part Numbers
Core
Frequency
(MHz)
Temperature
(Degree C)
Part Marking
266
70
GXm-266P 2.9V 70C
85
GXm-266P 2.9V 85C
70
GXm-266B 2.9V 70C
85
GXm-266B 2.9V 85C
233
70
GXm-233P 2.9V 70C
85
GXm-233P 2.9V 85C
70
GXm-233B 2.9V 70C
85
GXm-233B 2.9V 85C
200
70
GXm-200P 2.9V 70C
85
GXm-200P 2.9V 85C
70
GXm-200B 2.9V 70C
85
GXm-200B 2.9V 85C
180
70
GXm-180P 2.9V 70C
85
GXm-180P 2.9V 85C
70
GXm-180B 2.9V 70C
85
GXm-180B 2.9V 85C
Note:
B = BGA Package
P = SPGA Package
Table 7-2. Pins with 20-kohm
Internal Resistor
Signal Name
BGA
Ball No.
SPGA
Pin No.
PU/PD
SUSP#*
H2
M4
Pull-up
FRAME#
A8
C13
Pull-up
IRDY#
C9
D14
Pull-up
TRDY#
B9
B14
Pull-up
STOP#
C11
A15
Pull-up
LOCK#
B11
B16
Pull-up
DEVSEL#
A9
E15
Pull-up
PERR#
A11
D16
Pull-up
SERR#
C12
A17
Pull-up
REQ[2:0]#
D3,
H3,
E3
E3,
K2,
E1
Pull-up
TCLK
J2
P4
Pull-up
TMS
H1
N3
Pull-up
TDI
D2
F4
Pull-up
TEST
F3
J5
Pull-down
Note:
*SUSP# is pulled up when not active.