Intel Celeron M 440 1.86GHz BX80538440 Data Sheet
Product codes
BX80538440
Intel
®
Celeron
®
M Processor Datasheet
11
Low Power Features
2
Low Power Features
2.1
Clock Control and Low Power States
The Intel
Celeron M processor supports the AutoHALT, Stop Grant, Sleep, and Deep Sleep states
for optimal power management. See
for a visual representation of the processor low-
power states.
2.1.1
Normal State
This is the normal operating state for the processor.
2.1.2
AutoHALT Power-Down State
AutoHALT is a low-power state entered when the processor executes the HALT instruction. The
processor will transition to the Normal state upon the occurrence of SMI#, INIT#, LINT[1:0]
(NMI, INTR), or FSB interrupt message. RESET# will cause the processor to immediately
initialize itself.
initialize itself.
The return from a System Management Interrupt (SMI) handler can be to either Normal mode or
the AutoHALT Power-Down state. See the Intel Architecture Software Developer's Manual,
Volume III: System Programmer's Guide for more information.
Figure 1. Clock Control States
snoop
occurs
Stop
Grant
Normal
Sleep
HALT/
Grant
Snoop
Auto Halt
Deep
Sleep
STPCLK# asserted
SLP# asserted
SLP# de-asserted
STPCLK# de-asserted
snoop
serviced
HLT
instruction
snoop
serviced snoop
occurs
DPSLP#
de-asserted
DPSLP#
asserted
asserted
STPCLK#
asserted
STPCLK#
de-asserted
halt
break
V0001-04
Halt break - A20M#, INIT#, INTR, NMI, PREQ#, RESET#, SMI#, or APIC interrupt