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Revision 1.1
G
Electrical Specifications
(Continued)
Table 7-3 indicates which power rails are used for each sig-
nal of the SC1100 external interface. Power planes not
listed in this table are internal, and are not related to sig-
nals of the external interface.
7.1.4
DC current is not a simple measurement. Three of the
SC1100 power states (On, Active Idle, Sleep) were
selected for measurement. For each power state mea-
sured, two functional characteristics (Typical Average,
Absolute Maximum) are used to determine how much cur-
rent the SC1100 uses.
DC Current
7.1.4.1
The DC characteristics tables in this section list Core and
I/O current for three of the power states. For more explana-
tion on the SC1100 power states see Section 5.2.9 "Power
Management Logic" on page 134.
Power State Parameter Definitions
On (C0)
: All internal and external clocks with respect to
the SC1100 are running and all functional blocks inside
the GX1 module (CPU Core, Memory Controller, etc.)
are actively generating cycles. This is equivalent to the
ACPI specification’s “S0,C0” state.
Active Idle (C1)
: The CPU Core has been halted, all
other functional blocks are actively generating cycles.
This state is entered when a HLT instruction is executed
by the CPU Core. From a user’s perspective, this state is
indistinguishable from the On state and is equivalent to
the ACPI specification’s “S0,C1” state.
Sleep (SL2)
: This is the lowest power state the SC1100
can be in with voltage still applied to the device’s core
and I/O supply pins. This is equivalent to the ACPI spec-
ification’s “S1” state.
7.1.4.2
Definition and Measurement Techniques of
SC1100 Current Parameters
The following two parameters describe the SC1100 current
while in the On state:
Typical Average
: Indicates the average current used by
the SC1100 while in the On state. This is measured by
running typical Windows applications with power
management disabled (to guarantee that the SC1100
never goes into the Active Idle state). This number is
provided for reference only since it can vary greatly
depending on the usage model of the system.
Note:
This typical average should not be confused with
the typical power numbers shown in Table 7-2 on
page 281. The numbers in Table 7-2 are based on
a combination of On (Typical Average) and Active
Idle states.
Absolute Maximum
: Indicates the maximum instanta-
neous current used by the SC1100. CPU Core current is
measured by running the Landmark Speed 200
bench-
mark test (with power management disabled) and
measuring the peak current at any given instant during
the test. I/O current is measured by running Microsoft
Windows 98.
Table 7-3. Power Planes of External Interface Signals
Power Plane
Signal Names
V
CC
Balls
V
SS
Balls
Standby
GPWIO[0:2], ONCTL#, PWRBTN#, PWRCNT[1:2], THRM#,
IRRX1, RI#
V
SB
V
SS
Battery
X32I, X32O
V
BAT
V
SS
USB
DPOS_PORT1, DNEG_PORT1, DPOS_PORT2,
DNEG_PORT2, DPOS_PORT3, DNEG_PORT3
AV
CCUSB
AV
SSUSB
I/O
All other external interface signals
V
IO
V
SS