Sleep State-State 5; Datasheet - Intel SL8J6 - Pentium 4 Processor Datasheet

Features
6.2.5 Sleep State—State 5
The Sleep state is a very low power state in which the processor maintains its context, maintains
the phase-locked loop (PLL), and has stopped all internal clocks. The Sleep state can only be
entered from Stop-Grant state. Once in the Stop-Grant state, the processor will enter the Sleep state
upon the assertion of the SLP# signal. 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 erroneous processor operation.
Snoop events that occur while in Sleep State or during a transition into or out of Sleep state will
cause unpredictable behavior.
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# or RESET#)
are allowed on the FSB while the processor is in Sleep state. Any transition on an input signal
before the processor has returned to 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
Stop-Grant State. If RESET# is driven active while the processor is in the Sleep State, the SLP#
and STPCLK# signals should be de-asserted immediately after RESET# is asserted to ensure the
processor correctly executes the reset sequence.
Once in the Sleep state, the SLP# pin must be de-asserted if another asynchronous FSB event needs
to occur. The SLP# pin has a minimum assertion of one BCLK period.
When the processor is in the Sleep state, it will not respond to interrupts or snoop transactions.
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