307013-003 Datasheet, PDF (168/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

Functional Description
Power Button Override Function
If PWRBTN# is observed active for at least four consecutive seconds, the state machine
should unconditionally transition to the G2/S5 state, regardless of present state (S0–
S4), even if PWROK is not active. In this case, the transition to the G2/S5 state should
not depend on any particular response from the processor (e.g., a Stop-Grant cycle),
nor any similar dependency from any other subsystem.
The PWRBTN# status is readable to check if the button is currently being pressed or
has been released. The status is taken after the de-bounce, and is readable via the
PWRBTN_LVL bit.
Note:
The 4-second PWRBTN# assertion should only be used if a system lock-up has
occurred. The
4-second timer starts counting when the ICH7 is in a S0 state. If the PWRBTN# signal
is asserted and held active when the system is in a suspend state (S1–S5), the
assertion causes a wake event. Once the system has resumed to the S0 state, the 4-
second timer starts.
Note:
During the time that the SLP_S4# signal is stretched for the minimum assertion width
(if enabled by D31:F0:A4h bit 3), the Power Button is not a wake event. As a result, it
is conceivable that the user will press and continue to hold the Power Button waiting for
the system to awake. Since a
4-second press of the Power Button is already defined as an Unconditional Power down,
the power button timer will be forced to inactive while the power-cycle timer is in
progress. Once the
power-cycle timer has expired, the Power Button awakes the system. Once the
minimum SLP_S4# power cycle expires, the Power Button must be pressed for another
4 to 5 seconds to create the Override condition to S5.
Sleep Button
The Advanced Configuration and Power Interface, Version 2.0b defines an optional
Sleep button. It differs from the power button in that it only is a request to go from S0
to S1–S4 (not S5). Also, in an S5 state, the Power Button can wake the system, but the
Sleep Button cannot.
Although the ICH7 does not include a specific signal designated as a Sleep Button, one
of the GPIO signals can be used to create a “Control Method” Sleep Button. See the
Advanced Configuration and Power Interface, Version 2.0b for implementation details.
5.14.9.2
RI# (Ring Indicator)
The Ring Indicator can cause a wake event (if enabled) from the S1–S5 states.
Table 5-35 shows when the wake event is generated or ignored in different states. If in
the G0/S0/Cx states, the ICH7 generates an interrupt based on RI# active, and the
interrupt will be set up as a Break event.
Table 5-35. Transitions Due to RI# Signal
Present State
Event
RI_EN
S0
RI# Active
X
0
S1–S5
RI# Active
1
Event
Ignored
Ignored
Wake Event
Note:
Filtering/Debounce on RI# will not be done in ICH7. It can be in modem or external.
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Intel ^® ICH7 Family Datasheet