300 Datasheet, PDF (86/95 Pages) DB Lectro Inc – SCREW TYPE SERIES

Features
Figure 15. Processor Low Power State Machine
Normal State
Normal execution
HALT or MWAIT Instruction and
HALT Bus Cycle Generated
INIT#, BINIT#, INTR, NMI, SMI#,
RESET#, FSB interrupts
Enhanced HALT or HALT State
BCLK running
Snoops and interrupts allowed
STPCLK#
Asserted
STPCLK#
De-asserted
Stop Grant State
BCLK running
Snoops and interrupts allowed
STAPsCsLeKrt#eSdTDPeC-LaKss#erted
Snoop Event Occurs
Snoop Event Serviced
Snoop
Event
Occurs
Snoop
Event
Serviced
Enhanced HALT Snoop or HALT
Snoop State
BCLK running
Service snoops to caches
Stop Grant Snoop State
BCLK running
Service snoops to caches
6.2.1
6.2.2
Normal State
This is the normal operating state for the processor.
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.
86
Datasheet