Power Management
46
Datasheet
The processor exits a package C-state when a break event is detected. Depending on
the type of break event, the processor does the following:
•
If a core break event is received, the target core is activated and the break event
message is forwarded to the target core.
— If the break event is not masked, the target core enters the core C0 state and
the processor enters package C0.
— If the break event is masked, the processor attempts to re-enter its previous
package state.
•
If the break event was due to a memory access or snoop request.
— But the platform did not request to keep the processor in a higher package C-
state, the package returns to its previous C-state.
— And the platform requests a higher power C-state, the memory access or snoop
request is serviced and the package remains in the higher power C-state.
shows package C-state resolution for a dual-core processor.
summarizes package C-state transitions.
NOTE:
1.
If enabled, the package C-state will be C1E if all actives cores have resolved a core C1
state or higher.
Table 4-15.Coordination of Core Power States at the Package Level
Package C-State
Core 1
C0
C1
C3
Deep Power
Down
Technology
(code named
C6 state)
Co
re
0
C0
C0
C0
C0
C0
C1
C0
C1
1
C1
1
C1
1
C3
C0
C1
1
C3
C3
C6
C0
C1
1
C3
C6