Intel PentiumD 950 HH80553PG0964M Manual Do Utilizador
Códigos do produto
HH80553PG0964M
Features
92
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 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.
6.2.2.1
HALT Powerdown State
HALT is a low power state entered when all the logical processors have executed the
HALT or MWAIT instructions. When one of the logical processors executes the HALT
instruction, that logical processor is halted; however, the other processor continues
normal operation. The processor will transition to the Normal state upon the occurrence
of SMI#, BINIT#, INIT#, or LINT[1:0] (NMI, INTR). RESET# will cause the processor to
immediately initialize itself.
The return from a System Management Interrupt (SMI) handler can be to either
Normal Mode or the HALT Power Down state. See the Intel Architecture Software
Developer's Manual, Volume III: System Programmer's Guide for more information.
Figure 16.
Processor Low Power State Machine
Enhanced HALT or HALT State
BCLK running
Snoops and interrupts allowed
Snoops and interrupts allowed
Normal State
Normal execution
Enhanced HALT Snoop or HALT
Snoop State
Snoop State
BCLK running
Service snoops to caches
Service snoops to caches
Stop Grant State
BCLK running
Snoops and interrupts allowed
Snoops and interrupts allowed
Snoop
Event
Occurs
Snoop
Event
Serviced
INIT#, BINIT#, INTR, NMI, SMI#,
RESET#, FSB interrupts
RESET#, FSB interrupts
STPCLK#
Asserted
Asserted
STPCLK#
De-asserted
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
HALT Bus Cycle Generated
Stop Grant Snoop State
BCLK running
Service snoops to caches
Service snoops to caches