Datasheet
93
Features
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
). While
the processor is in the Sleep state, the SLP# pin must be deasserted if another
asynchronous FSB event needs to occur. PECI is not available and will not respond
while in the Sleep State.
6.2.6
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 with
the CK505 clock chip 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# de-assertion and start toggling BCLK within 10 BCLK
periods.
To re-enter the Sleep state, the DPSLP# pin must be deasserted. BCLK can be restarted
after DPSLP# de-assertion 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. Any transition on an
input signal before the processor has returned to the Stop-Grant state will result in
unpredictable behavior. PECI is not available and will not respond while in the Deep
Sleep State.
6.2.7
Deeper Sleep State
The Deeper Sleep state is similar to the Deep Sleep state but the core voltage is
reduced to a lower level. The Deeper Sleep state is entered through assertion of the
DPRSTP# pin while in the Deep Sleep state. Exit from Deeper Sleep is initiated by
DPRSTP# de-assertion. PECI is not available and will not respond while in the Deeper
Sleep State.
