Intel P6200 CP80617004122AW Data Sheet

Datasheet

91

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 will support this feature will be provided in 

future releases of the Intel

Specification Update when available.

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 points. It alters the 

performance of the processor by changing the bus to core frequency ratio and voltage. 

This allows the processor to run at different core frequencies and voltages to best serve 

the performance and power requirements of the processor and system. The processor 

has hardware logic that coordinates the requested voltage (VID) between the processor 

cores. The highest voltage that is requested for either of the processor cores is selected 

for that processor package. Note that the front side bus is not altered; only the internal 

core frequency is changed. To run at reduced power consumption, the voltage is altered 

in step with the bus ratio.

The following are key features of Enhanced Intel SpeedStep Technology:

• Multiple voltage/frequency operating points provide optimal performance at 

reduced power consumption.

• Voltage/frequency selection is software controlled by writing to processor MSR’s 

(Model Specific Registers), thus eliminating chipset dependency.

— If the target frequency is higher than the current frequency, V

CC

 is incriminated 

in steps (+12.5 mV) by placing a new value on the VID signals and the 

processor shifts to the new frequency. Note that the top frequency for the 

processor can not be exceeded.

— If the target frequency is lower than the current frequency, the processor shifts 

to the new frequency and V

CC

 is then decremented in steps (-12.5 mV) by 

changing the target VID through the VID signals.