SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 359

• Manufacturer Part Number: SC2200
• Description: Thin Client On a Chip
• Manufacturer: NSC [National Semiconductor]

Revision 3.0
Electrical Specifications
Table 8-3 indicates which power rails are used for each sig-
nal of the SC2200 external interface. Power planes not
8.1.4
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
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
• Active Idle (C1): The CPU Core has been halted, all
• Sleep (SL2): This is the lowest power state the SC2200
Power Plane
Standby
Battery
CRT DAC
USB
I/O
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.
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.
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.
DC Current
Power State Parameter Definitions
Signal Names
GPWIO[0:2], LED#, ONCTL#, PWRBTN#, PWRCNT[1:2],
THRM#, CLK32, IRRX1, RI2#, SDATA_IN2
X32I, X32O
RED, GREEN, BLUE, VREF, SETRES
DPOS_PORT1, DNEG_PORT1, DPOS_PORT2,
DNEG_PORT2, DPOS_PORT3, DNEG_PORT3
All other external interface signals
Table 8-3. Power Planes of External Interface Signals
(Continued)
359
listed in this table are internal, and are not related to sig-
nals of the external interface.
8.1.4.2
The following two parameters describes the SC2200 cur-
rent while in the On state:
• Typical Average: Indicates the average current used by
Note:
• Absolute Maximum: Indicates the maximum instanta-
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.
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).
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.
Definition and Measurement Techniques of
SC2200 Current Parameters
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