Intel Celeron 365 HH80552RE104512 User Manual

Product codes
HH80552RE104512
Page of 95
Features
86
Datasheet
6.2.1
Normal State
This is the normal operating state for the processor.
6.2.2
HALT and Enhanced HALT Powerdown States
The Celeron D processor supports the HALT or Enhanced HALT powerdown state. The 
Enhanced HALT Powerdown state is configured and enabled via the BIOS. The 
Enhanced HALT state must be enabled via the BIOS for the processor to remain within 
its specifications. 
The Enhanced HALT state is a lower power state as compared to the Stop Grant State.
If Enhanced HALT is not enabled, the default Powerdown state entered will be HALT. 
Refer to the following sections for details about the HALT and Enhanced HALT states.
Figure 15.
Processor Low Power State Machine
Enhanced HALT or HALT State
BCLK running
Snoops and interrupts allowed
Normal State
Normal execution
Enhanced HALT Snoop or HALT
Snoop State
BCLK running
Service snoops to caches
Stop Grant State
BCLK running
Snoops and interrupts allowed
Snoop
Event
Occurs
Snoop
Event
Serviced
INIT#, BINIT#, INTR, NMI, SMI#,
RESET#, FSB interrupts
STPCLK#
Asserted
STPCLK#
De-asserted
S
TPCL
K
#
Asse
rted
STP
CL
K
#
D
e-
asse
rte
d
Snoop Event Occurs
Snoop Event Serviced
HALT or MWAIT Instruction and
HALT Bus Cycle Generated
Stop Grant Snoop State
BCLK running
Service snoops to caches