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INTEL PENTI UM II PROCESSOR MOBILE MODULE MMC-1
4.4.2. Normal State
The normal operating mode for the mobile Pentium II
processor. The processor’s core clock is running and the
processor is actively executing instructions.
4.4.3. Auto Halt State
This is a low-power mode entered through the HLT
instruction. The power level is similar to the Stop Grant state.
A transition to the Normal state is made by a halt break
event (one of the following signals going active: NMI, INTR,
BINIT#, INIT#, RESET#, FLUSH#, or SMI#).
Asserting the STPCLK# signal while in the Auto Halt state
will cause the processor to transition to the Stop Grant or
Quick Start state, which issues a Stop Grant Acknowledge
bus cycle. Deasserting STPCLK# will cause the processor to
return to the Auto Halt state without issuing a new Halt bus
cycle.
The SMI# (System Management Interrup t) is recogni z ed in
the Auto Halt state. The return from the SMI handler can be
to either the Normal state or the Auto Halt state. See the
Intel ® Architecture Software Developer’ s Manual, Volume
III: System Programmer’s Guide
for more information. No
Halt bus cycle is issued when returning to the Auto Halt state
from System Mana gement M ode (SMM).
The FLUSH# signal i s serviced in th e Auto Halt state . After
flushing the on-chip, the processor will return to the Auto
Halt state without issuing a Halt bus cycle. Transitions in the
A20M# and PREQ# signals are recognized while in the Auto
Halt state.
4.4.4. Stop Grant State
The Stop Grant state is not supported in the Intel mobile
modules The processor enters this mode with the assertion
of the STPCLK# signal when it is configured for Stop Grant
state (via the A15# strapping option). The processor is still
able to respond to snoop requests and latch interrupts.
Latched interrupts will be serviced when the processor
returns to the Normal state. Only one occurrence of each
interrupt event will be latched. A transition back to the
Normal state can be made by the deassertion of the
STPCLK# signal or the occurrence of a stop break event (a
BINIT#, FLUSH #, or RESET# assert ion).
The processor will return to the Stop Grant state after the
comp le tion of a B INI T # bus in iti al iz ati on unles s STPCLK #
has been deasserted. RESET# assertion will cause the
processor to immediately initialize itself, but the processor
will stay in the Stop Grant state after initialization until
STPCLK# is deasserted. If the FLUSH# signal is asserted,
the processor will flush the on-chip caches and return to the
Stop Grant state. A transition to the Sleep state can be made
by the assertion of the SLP# signal.
While in the Stop Grant state, assertions of SMI#, INIT#,
INTR, and NMI (or LINT[1:0]) will be latched by the
processor. These latched events will not be serviced until the
processor returns to the Normal state. Only one of each
event will be recognized upon return to the Normal state.
4.4.5. Quick Start State
This is a mode entered with the assertion of the STPCLK#
signal when it is configured for the Quick Start state (via the
A15# strapping option). In the Quick Start state the
processor is only capable of acting on snoop transactions
generated by the system bus priority device. Because of its
snooping behavior, Quick Start can only be used in UP
configuration. A transition to the Deep Sleep state can be
made by stopping the clock input to the processor. A
transition back to the Normal state (from the Quick Start
state) is made only if the STPCLK# signal is deasserted.
While in this state the processor is limited in its ability to
respon d to inpu t. It is incapa ble of latching an y interrupts,
servicing snoop transactions from symmetric bus masters, or
res po nd in g to FLU SH# or BIN IT # as s ert i ons . Whil e t he
processor is in the Quick Start state, it will not respond
properly to any input signal other than STPCLK#, RESET#,
or BPRI#. If any other input signal changes, then the
behavior of the processor will be unpredictable. No serial
interrupt messages may begin or be in progress while the
processor is in the Quick Start state. RESET# assertion will
cause the processor to immediately initialize itself, but the
processor will stay in the Quick Start state after initialization
unt il STP C LK# is deas s er te d.
4.4.6. HALT/Grant Snoop State
The processor will respon d to snoop transactions on the
system bus while in the Auto Halt, Stop Gra nt, or Quick Start
state. When a snoop t ransac tion is presented on the system
bus the processor will enter the HALT/Grant Snoop state.
The processor will remain in this state until the snoop has
been serviced and the system bus is quiet. After th e snoop
has been serviced, the processor will return to its previous
state. If the HALT/Grant Snoop state is entered from the
Quick Start state, then the input signal re strictions of the
Quick Start state still apply in the HALT/Grant Snoop state,
except for those signal transitions that are required to
perform the snoop.
4.4.7. Sleep State
The Sleep state is a very low power state in which the
processor maintains its context and the phase-locked loop
(PLL) maintains phase lock. The Sleep state can only be
entered from the Stop Grant state. After entering the Stop
Grant state th e SLP# signal can be asserted, causing the
processor to enter the Sleep state. The SLP# signal is not
recognized in the Normal or Auto Halt states.
The processor can be reset by the RESET# signal while in
the Sleep state. If RESET# is driven active while the
processor is in the Sleep state then SLP# and STPCLK#
must immediately be dr iven inactive to ensure that the
processor correctly initializes itself.
Input signals (other than RESET#) may not change while the
processor is in the Sleep state or transitioning into or out of