SC1100 Datasheet, PDF (136/348 Pages) National Semiconductor (TI) – Geode™ Information Appliance On a Chip

Core Logic Module (Continued)
5.2.9.3 Power Planes Control
The SC1100 supports up to three power planes. Three sig-
nals are used to control these power planes. Table 5-6
describes the signals and when each is asserted.
Table 5-6. Power Planes Control Signals vs.
Sleep States
Signal
SL4
and
S0 SL1 SL2 SL3 SL5
PWRCNT1
1
1
0
0
0
PWRCNT2
1
1
1
0
0
ONCTL#
0
0
0
0
1
These signals allow control of the power of system devices
and the SC1100 itself. Table 5-7 describes the SC1100
power planes with respect to the different Sleep and Global
states.
Table 5-7. Power Planes vs. Sleep/Global States
Sleep/
Global
State
V_CORE, V_I/O,
V_PLL
V_SB, V_SBL
V_BAT
S0, SL1 and
On
SL2
SL3, SL4
Off
and SL5
G3
Off
No Power
Off
Illegal
On
On
On or Off
On
On or Off
Off
On
Off
Off
Off
On or Off
The SC1100 power planes are controlled externally by the
three signals (i.e., the system designer should make sure
the system design is such that Table 5-7 is met) for all sup-
ported Sleep states.
V_SB and V_BAT are not controlled by any control signal. V_SB
exists as long as the AC power is plugged in (for desktop
systems) or the main battery is charged (for mobile sys-
tems). V_BAT exists as long as the RTC battery is charged.
The case in which V_SB does not exist is called Mechanical
Off (G3).
5.2.9.4 Power Management Events
The SC1100 supports power management events that can
manage:
• Transition of the system from a Sleep state to a Work
state. This is done by the hardware. These events are
defined as wakeup events.
• Enabled wakeup events to set the WAK_STS bit
(F1BAR1+I/O Offset 08h[15]) to 1, when transitioning
the system back to the working state.
• Generation of an interrupt. This invokes the relevant
software driver. The interrupt can either be an SMI or
SCI (selected by the SCI_EN bit, F1BAR1+I/O Offset
0Ch[0]). These events are defined as interrupt events.
Table 5-8 lists the power management events that can gen-
erate an SCI or SMI.
Table 5-8. Power Management Events
Event
SCI
SMI
Power Button
Yes
Yes
Power Button Override
Yes
-
Bus Master Request
Yes
-
Thermal Monitoring
Yes
Yes
USB
Yes
Yes
RTC
Yes
Yes
ACPI Timer
Yes
Yes
GPIO
Yes
Yes
IRRX1
Yes
Yes
RI2#
Yes
Yes
GPWIO
Yes
Yes
Internal SMI signal
Yes
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