SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 425

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

Revision 3.0
Electrical Specifications
ACPI is non-functional when the power-up sequence does not include using the power button. If ACPI functionality is
desired, the power button must be toggled. This can be done externally or internally. GPIO63 is internally connected to
PWRBTN#. To toggle the power button with software, GPIO63 must be programmed as an output using the normal GPIO
programming protocol (see Section 5.4.1.1 "GPIO Support Registers" on page 231). GPIO63 must be pulsed low for at
least 16 msec and not more than 4 sec. Asserting POR# has no effect on ACPI. If POR# is asserted and ACPI was active
prior to POR#, then ACPI will remain active after POR#. Therefore, BIOS must ensure that ACPI is inactive before GPIO63
is pulsed low.
Symbol
t
t
t
1
2
3
1)
2)
V
SBL,
V
V
V
SBL
SB
SB,
V
32KHZ
CORE
POR#
and V
Table 8-44. Power-Up Sequence Not Using the Power Button Timing Parameters
and V
V
Parameter
Voltage sequence
POR# inactive after V
and V
32KHZ startup time
IO
1
2
IO
Figure 8-56. Power-Up Sequencing Without PWRBTN# Timing Diagram
CORE
IO
should be tied together.
applied
should be tied together.
t
1
(Continued)
SBL
, V
t
2
CORE
, V
SB
,
Min
-10
50
425
t
3
Max
10
1
Unit
ms
ms
s
Comments
POR# must not glitch during
active time.
Time required for 32 KHz oscilla-
tor and 14.318 MHz derived from
PLL6 to become stable at which
time the RTC can reliably count.
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