SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 360

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

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Electrical Specifications
8.1.4.3
The SC2200’s current is highly dependent on two func-
tional characteristics, DCLK (DOT clock) and SDRAM fre-
quency. Table 8-4 shows how these factors are controlled
when measuring the typical average and absolute maxi-
mum processor current parameters.
8.1.4.4
Table 8-5 and Table 8-6 show the DC current measure-
ments of the SC2200. The SC2200 supports CRT and TFT
1.
2.
3.
CPU Current Measurement
Typical Average
Absolute Maximum
Symbol
I
I
I
I
CC3ON
COREON
SBON
SBLON
See Table 8-2 on page 358 for nominal and maximum voltages.
A DCLK frequency of 50 MHz is derived by setting the display mode to 800x600x8 bpp at 75 Hz, using a display image
of vertical stripes (4-pixel wide) alternating between black and white with power management disabled.
A DCLK frequency of 135 MHz is derived by setting the display mode to 1280x1024x8 bpp at 75 Hz, using a display
image of vertical stripes (1-pixel wide) alternating between black and white with power management disabled.
Table 8-4. System Conditions Used to Measure SC2200’s Current Used During the "On" State
Definition of System Conditions for Measur-
ing On Parameters
DC Current Measurements
Parameter
f
(Nominal); CPU mode = On, excludes TFT
interface contribution and CRT DAC
f
(Nominal); CPU mode = On, excludes TFT
interface contribution and CRT DAC
f
(Nominal); CPU mode = On, excludes TFT
interface contribution and CRT DAC
f
1.8V (Nominal); CPU mode = On
f
1.8V (Nominal); CPU mode = On
f
2.0V (Nominal); CPU mode = On
SB Current @ V
mode = On
SBL Current @ V
mode = On
SBL Current @ V
mode = On
CLK
CLK
CLK
CLK
CLK
CLK
= 233 MHz, I/O Current @ V
= 266 MHz, I/O Current @ V
= 300 MHz, I/O Current @ V
= 233 MHz, Core Current @ V
= 266 MHz, Core Current @ V
= 300 MHz, Core Current @ V
1
SB
SBL
SBL
= 3.3V (Nominal); CPU
(Continued)
= 1.8V (Nominal); CPU
= 2.0V (Nominal); CPU
Table 8-5. DC Characteristics On Mode
Nominal
V
IO
IO
IO
CORE
Max
CORE
CORE
CORE
= 3.3V
= 3.3V
= 3.3V
1
=
=
=
360
displays, but it is expected that generally only one display
interface will be used. Power consumed by the SC2200 is
different with different displays. The CRT DAC requires cur-
rent, while the TFT interface even though it has no DAC to
power, also draws current while it is active. The CRT DAC
and the TFT interface are presented as separate line items.
The chosen display type I/O current should be added to the
Typical, Absolute Maximum, and Active Idle I/O currents to
get total current.
Typ Avg
1050
230
240
250
820
900
10
10
1
Nominal
V
Max
IO
System Conditions
1
Abs Max
1090
1330
250
260
270
990
20
20
2
DCLK Freq.
135 MHz
50 MHz
Unit
mA
mA
mA
mA
2
3
Comments
I
I
CC
CC
SDRAM Freq.
for V
for V
Nominal
Max
IO
CORE
Revision 3.0