X9000 Datasheet, PDF (16/77 Pages) Intel Corporation – Core2 Duo Processor and Core2 Extreme Processor on 45-nm Process

Low Power Features
2.1.2.3
2.1.2.4
2.1.2.5
Stop-Grant Snoop State
The processor responds to snoop or interrupt transactions on the FSB while in Stop-
Grant state by entering the Stop-Grant Snoop state. The processor will stay in this
state until the snoop on the FSB has been serviced (whether by the processor or
another agent on the FSB) or the interrupt has been latched. The processor returns to
the Stop-Grant state once the snoop has been serviced or the interrupt has been
latched.
Sleep State
The Sleep state is a low-power state in which the processor maintains its context,
maintains the phase-locked loop (PLL), and stops all internal clocks. The Sleep state is
entered through assertion of the SLP# signal while in the Stop-Grant state. The SLP#
pin should only be asserted when the processor is in the Stop-Grant state. SLP#
assertions while the processor is not in the Stop-Grant state is out of specification and
may result in unapproved operation.
In the Sleep state, the processor is incapable of responding to snoop transactions or
latching interrupt signals. No transitions or assertions of signals (with the exception of
SLP#, DPSLP# or RESET#) are allowed on the FSB while the processor is in Sleep
state. Snoop events that occur while in Sleep state or during a transition into or out of
Sleep state will cause unpredictable behavior. Any transition on an input signal before
the processor has returned to the Stop-Grant state will result in unpredictable behavior.
If RESET# is driven active while the processor is in the Sleep state, and held active as
specified in the RESET# pin specification, then the processor will reset itself, ignoring
the transition through the Stop-Grant state. If RESET# is driven active while the
processor is in the Sleep state, the SLP# and STPCLK# signals should be deasserted
immediately after RESET# is asserted to ensure the processor correctly executes the
Reset sequence.
While in the Sleep state, the processor is capable of entering an even lower power
state, the Deep Sleep state, by asserting the DPSLP# pin (See Section 2.1.2.5). While
the processor is in the Sleep state, the SLP# pin must be deasserted if another
asynchronous FSB event needs to occur.
Deep Sleep State
The Deep Sleep state is entered through assertion of the DPSLP# pin while in the Sleep
state. BCLK may be stopped during the Deep Sleep state for additional platform level
power savings. BCLK stop/restart timings on appropriate chipset-based platforms are
as follows:
• Deep Sleep entry: the system clock chip may stop/tristate BCLK within two BCLKs
of DPSLP# assertion. It is permissible to leave BCLK running during Deep Sleep.
• Deep Sleep exit: the system clock chip must drive BCLK to differential DC levels
within 2-3 ns of DPSLP# deassertion and start toggling BCLK within 10 BCLK
periods.
To re-enter the Sleep state, the DPSLP# pin must be deasserted. BCLK can be re-
started after DPSLP# deassertion as described above. A period of 15 microseconds (to
allow for PLL stabilization) must occur before the processor can be considered to be in
the Sleep state. Once in the Sleep state, the SLP# pin must be deasserted to re-enter
the Stop-Grant state.
While in the Deep Sleep state, the processor is incapable of responding to snoop
transactions or latching interrupt signals. No transitions of signals are allowed on the
FSB while the processor is in the Deep Sleep state. When the processor is in the Deep
Sleep state it will not respond to interrupts or snoop transactions.
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Datasheet