Configuration and Low Power Features
The clock may be stopped when the processor is in the Deep Sleep state in order to support the
ACPI S1 state. The clock may only be stopped after DPSLP# is asserted and must be restarted
before DPSLP# is deasserted. To provide maximum power conservation when stopping the clock
during Deep Sleep, hold the BLCK0 input at V and the BCLK1 input at V
.
OL
OH
While in Deep Sleep state, the processor is incapable of responding to snoop transactions or
latching interrupt signals. No transitions of signals are allowed on the system bus while the
processor is in Deep Sleep state. Any transition on an input signal before the processor has returned
to Stop-Grant state will result in unpredictable behaviour.
7.2.7
Deeper Sleep State
The Deeper Sleep State is the lowest state power the processor can enter. This state is functionally
identical to the Deep Sleep state but at a lower core voltage. The control signals to the voltage
regulator to initiate a transition to the Deeper Sleep state are provided on the platform. Please refer
the Mobile Intel Pentium 4 Processor-M and Intel 845MP/845MZ Chipset Platform Design
Guide.
7.3
Enhanced Intel SpeedStep Technology
The Mobile Intel Pentium 4 Processor-M, when used in conjunction with the requisite Intel
SpeedStep technology applet or its equivalent, supports Enhanced Intel SpeedStep technology.
Enhanced Intel SpeedStep technology allows the processor to switch between two core frequencies
automatically based on CPU demand, without having to reset the processor or change the system
bus frequency. The processor has two bus ratios and voltages programmed into it instead of one
and the GHI# signal controls which bus ratio and voltage is used. After reset, the processor will
start in the lower of its two core frequencies, the “Battery Optimized” mode. An operating mode
transition to the high core frequency can be made by setting GHI# low, putting the processor into
the Deep Sleep state, regulating to the new VID output, and returning to the Normal state. This puts
the processor into the high core frequency, or “Maximum Performance” operating mode. Going
through these steps with GHI# set high, transitions the processor back to the low core frequency
operating mode. The processor will drive the VID[4:0] pins with the VID of the current operating
mode and the system logic is required to regulate the core voltage within specification for the
driven VID.
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Mobile Intel Pentium 4 Processor-M Datasheet
INTEL [ INTEL ]
