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Electrical Specifications (Continued)

Table 8-3 indicates which power rails are used for each sig-

nal of the SC2200 external interface. Power planes not

listed in this table are internal, and are not related to sig-

nals of the external interface.

8.1.4

DC Current

DC current is not a simple measurement. Three of the

SC2200 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 SC2200 uses.

8.1.4.1

Power State Parameter Definitions

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 SC2200 power states see Section 5.2.9 "Power

Management Logic" on page 167.

•On (C0): All internal and external clocks with respect to

the SC2200 are running and all functional blocks inside

the GX1 module (CPU Core, Memory Controller, Display

Controller, etc.) are actively generating cycles. This is

equivalent to the ACPI specification’s “S0,C0” state.

• ActiveIdle(C1): The CPU Core has been halted, all

other functional blocks (including the Display Controller

for refreshing the display) 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 SC2200

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.

8.1.4.2

Definition and Measurement Techniques of

SC2200 Current Parameters

The following two parameters describes the SC2200 cur-

rent while in the On state:

• Typical Average: Indicates the average current used by

the SC2200 while in the On state. This is measured by

running typical Windows applications in a typical display

mode. In this case, 800x600x8 bpp at 75 Hz, 50 MHz

DCLK using a background image of vertical stripes (4-

pixel wide) alternating between black and white with

power management disabled (to guarantee that the

SC2200 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. Typical power is based

on a combination of On (Typical Average) and

Active Idle states.

• Absolute Maximum: Indicates the maximum instanta-

neous current used by the SC2200. 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 and using a background image of vertical

stripes (1-pixel wide) alternating between black and

white at the maximum display resolution of each of the

display type supported (CRT and TFT).

Table 8-3. Power Planes of External Interface Signals

Power Plane

Signal Names

VCC Balls

VSS Balls

Standby

GPWIO[0:2], LED#, ONCTL#, PWRBTN#, PWRCNT[1:2],

THRM#, CLK32, IRRX1, RI2#, SDATA_IN2

VSB

VSS

Battery

X32I, X32O

VBAT

VSS

CRT DAC

RED, GREEN, BLUE, VREF, SETRES

AVCCCRT

AVSSCRT

USB

DPOS_PORT1, DNEG_PORT1, DPOS_PORT2,

DNEG_PORT2, DPOS_PORT3, DNEG_PORT3

AVCCUSB

AVSSUSB

I/O

All other external interface signals

VIO

VSS

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