Intel Core 2 Extreme QX6850 BX80569QX6850 User Manual

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Extended Stop Grant is a low power state entered when the STPCLK# signal is asserted 

and Extended Stop Grant has been enabled via the BIOS. 

The processor will automatically transition to a lower frequency and voltage operating 

point before entering the Extended Stop Grant state. When entering the low power 

state, the processor will first switch to the lower bus ratio and then transition to the 

lower VID.  

The processor exits the Extended Stop Grant state when a break event occurs. When 

the processor exits the Extended Stop Grant state, it will resume operation at the lower 

frequency, transition the VID to the original value, and then change the bus ratio back 

to the original value. 

The Extended HALT Snoop State is used in conjunction with the new Extended HALT 

state. If Extended HALT state is not enabled in the BIOS, the default Snoop State 

entered will be the HALT Snoop State. Refer to the following sections for details on 

HALT Snoop State, Stop Grant Snoop State and Extended HALT Snoop State, and 

Extended Stop Grant Snoop State.

The processor will respond to snoop transactions on the FSB while in Stop Grant state 

or in HALT Power Down state. During a snoop transaction, the processor enters the 

HALT Snoop State:Stop Grant Snoop state. The processor will stay in this state until the 

snoop on the FSB has been serviced (whether by the processor or another agent on the 

FSB). After the snoop is serviced, the processor returns to the Stop Grant state or HALT 

Power Down state, as appropriate.

The processor will remain in the lower bus ratio and VID operating point of the 

Extended HALT state or Extended Stop Grant state. While in the Extended HALT Snoop 

State or Extended Stop Grant Snoop State, snoops are handled the same way as in the 

HALT Snoop State or Stop Grant Snoop State. After the snoop is serviced, the 

processor will return to the Extended HALT state or Extended Stop Grant state. 

The processor supports Enhanced Intel SpeedStep

® 

Technology. This technology 

enables the processor to switch between multiple frequency and voltage points, which 

results in platform power savings. Enhanced Intel SpeedStep

 

Technology requires 

support for dynamic VID transitions in the platform. Switching between voltage/

frequency states is software controlled. 

Not all processors are capable of supporting Enhanced Intel SpeedStep

®

 Technology. 

More details on which processor frequencies support this feature is provided in the 

Extreme Processor X6800 Specification Update.

Enhanced Intel SpeedStep

®

 Technology creates processor performance states (P-

states) or voltage/frequency operating points. P-states are lower power capability 

states within the Normal state as shown in 

. Enhanced Intel SpeedStep

®

 

Technology enables real-time dynamic switching between frequency and voltage