Features
94
Intel® Xeon® Processor 3500 Series Datasheet Volume 1
7.2.1
Thread and Core Power State Descriptions
Individual threads may request low power states. Core power states are automatically
resolved by the processor as shown in
Notes:
1.
If enabled, state will be C1E.
7.2.1.1
C0 State
This is the normal operating state in the processor.
7.2.1.2
C1/C1E State
C1/C1E is a low power state entered when all threads within a core execute a HLT or
MWAIT(C1E) instruction. The processor thread will transition to the C0 state upon
occurrence of an interrupt or an access to the monitored address if the state was
entered via the MWAIT instruction. RESET# will cause the processor to initialize itself.
A System Management Interrupt (SMI) handler will return execution to either Normal
state or the C1 state. See the
Intel
®
64 and IA-32 Architectures Software Developer's
Manuals, Volume III: System Programmer's Guide
for more information.
Figure 7-1. Power States
C0
1. No transition to C0 is needed to service a snoop when in C1 or C1E.
,
.
2. Transitions back to C0 occur on an interrupt or on access to monitored address (if state was entered via MWAIT).
.
2
2
C1
1
1
C E
1
C3
C6
2
2
MWAIT C1,
HLT
MWAIT C1,
HLT (C1E
enabled)
MWAIT C6,
I/O C6
MWAIT C3,
I/O C3
Table 7-2.
Coordination of Thread Power States at the Core Level
Core State
Thread1 State
C0
C1
1
C3
C6
Thread0
State
C0
C0
C0
C0
C0
C1
1
C0
C1
1
C1
1
C1
1
C3
C0
C1
1
C3
C3
C6
C0
C1
1
C3
C6
Summary of Contents for Xeon 3500 Series
Page 1: ...Document Number 321332 002 Intel Xeon Processor 3500 Series Datasheet Volume 1 July 2009 ...
Page 8: ...8 Intel Xeon Processor 3500 Series Datasheet Volume 1 ...
Page 12: ...Introduction 12 Intel Xeon Processor 3500 Series Datasheet Volume 1 ...
Page 92: ...Thermal Specifications 92 Intel Xeon Processor 3500 Series Datasheet Volume 1 ...
Page 98: ...Features 98 Intel Xeon Processor 3500 Series Datasheet Volume 1 ...