Normal State; Halt And Extended Halt Powerdown States; Processor Low Power State Machine - Intel E3300 Datasheet

Figure 17.

Processor Low Power State Machine

Normal State

- Normal Execution
STPCLK#
Asserted
Stop Grant State
- BCLK running
- Snoops and interrupts
SLP#
Asserted
Sleep State
- BCLK running
- No Snoops or
interrupts allowed
- PECI unavailable in
this state
6.2.1 Normal State
This is the normal operating state for the processor.
6.2.2

HALT and Extended HALT Powerdown States

The processor supports the HALT or Extended HALT powerdown state. The Extended
HALT powerdown state must be configured and enabled using the BIOS for the
processor to remain within specification.
The Extended HALT state is a lower power state as compared to the Stop Grant State.
If Extended HALT is not enabled, the default powerdown state entered will be HALT.
Refer to the sections below for details about the HALT and Extended HALT states.
86
HALT or MWAIT Instruction and
HALT Bus Cycle Generated
INIT#, INTR, NMI, SMI#, RESET#,
FSB interrupts
STPCLK#
De-asserted
allowed
SLP#
De-asserted
DPSLP#
Asserted
DPSLP#
De-asserted
STPCLK#
STPCLK# De-asserted
Asserted
Snoop Event Occurs
Snoop Event Serviced
DPRSTP#
Asserted
Deep Sleep State
- BCLK can be stopped
- No Snoops or
interrupts allowed
- PECI unavailable in
DPRSTP#
this state
De-asserted
Features
Extended HALT or HALT
State
- BCLK running
- Snoops and interrupts
allowed
Snoop Snoop
Event Event
Occurs Serviced
Extended HALT Snoop or
HALT Snoop State
- BCLK running
- Service Snoops to caches
Extended Stop Grant or
Stop Grant Snoop State
- BCLK running
- Service Snoops to caches
Deeper Sleep State
- BCLK can be stopped
- No Snoops or
interrupts allowed
- PECI unavailable in
this state
Datasheet