X6800 Datasheet, PDF (88/122 Pages) Intel Corporation – Core2 Extreme Processor

Thermal Specifications and Design Considerations
Figure 26. Thermal Monitor 2 Frequency and Voltage Ordering
T
TM2
f
MAX
f
TM2
VID
VID
TM2
Temperature
Frequency
VID
5.2.3
PROCHOT#
The PROCHOT# signal is asserted when a high temperature situation is detected,
regardless of whether Thermal Monitor or Thermal Monitor 2 is enabled.
It should be noted that the Thermal Monitor 2 TCC cannot be activated via the on
demand mode. The Thermal Monitor TCC, however, can be activated through the use of
the on demand mode.
On-Demand Mode
The processor provides an auxiliary mechanism that allows system software to force
the processor to reduce its power consumption. This mechanism is referred to as “On-
Demand” mode and is distinct from the Thermal Monitor feature. On-Demand mode is
intended as a means to reduce system level power consumption. Systems using the
processor must not rely on software usage of this mechanism to limit the processor
temperature.
The processor provides an auxiliary mechanism that allows system software to force
the processor to reduce its power consumption. This mechanism is referred to as “On-
Demand” mode and is distinct from the Thermal Monitor and Thermal Monitor 2
features. On-Demand mode is intended as a means to reduce system level power
consumption. Systems must not rely on software usage of this mechanism to limit the
processor temperature. If bit 4 of the IA32_CLOCK_MODULATION MSR is set to a 1, the
processor will immediately reduce its power consumption via modulation (starting and
stopping) of the internal core clock, independent of the processor temperature. When
using On-Demand mode, the duty cycle of the clock modulation is programmable via
bits 3:1 of the same IA32_CLOCK_MODULATION MSR. In On-Demand mode, the duty
cycle can be programmed from 12.5% on/ 87.5% off to 87.5% on/ 12.5% off in 12.5%
increments. On-Demand mode may be used in conjunction with the Thermal Monitor;
however, if the system tries to enable On-Demand mode at the same time the TCC is
engaged, the factory configured duty cycle of the TCC will override the duty cycle
selected by the On-Demand mode.
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Datasheet