Intel LF80550KF100007 Data Sheet
Dual-Core Intel® Xeon® Processor 7100 Series Datasheet
79
Thermal Specifications
The PROCHOT# signal is asserted when a high temperature situation is detected,
regardless of whether Thermal Monitor or Thermal Monitor 2 is enabled.
regardless of whether Thermal Monitor or Thermal Monitor 2 is enabled.
If a processor has its Thermal Control Circuit activated via a Thermal Monitor 2 event,
and an Enhanced Intel SpeedStep® Technology transition to a higher target frequency
(through the applicable MSR write) is attempted, this frequency transition will be
delayed until the TCC is deactivated and the TM2 event is complete.
and an Enhanced Intel SpeedStep® Technology transition to a higher target frequency
(through the applicable MSR write) is attempted, this frequency transition will be
delayed until the TCC is deactivated and the TM2 event is complete.
Note:
Not all processors are capable of supporting Thermal Monitor 2. More details on which
processor frequencies will support this feature will be provided in future releases of the
NDA Specification Update.
6.2.3
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 and Thermal Monitor 2
features. On-Demand mode is intended as a means to reduce system level power
consumption. Systems utilizing the Dual-Core Intel Xeon processor 7100 series
processor must not rely on software usage of this mechanism to limit the processor
temperature.
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 utilizing the Dual-Core Intel Xeon processor 7100 series
processor must not rely on software usage of this mechanism to limit the processor
temperature.
If bit 4 of the IA_32_CLOCK_MODULATION MSR is written 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 IA_32_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 or
Thermal Monitor 2. If Thermal Monitor is enabled and 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.
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 IA_32_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 or
Thermal Monitor 2. If Thermal Monitor is enabled and 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.
Figure 6-4. Thermal Monitor 2 Frequency and Voltage Ordering
Vcc
Temperature
V
NOM
Frequency
Time
f
TM2
f
MAX
T
TM2
V
TM2
T(hysteresis)