Справочник Пользователя для Intel 2 Duo T7400 LE80537GF0484M
Модели
LE80537GF0484M
Datasheet
85
Thermal Specifications and Design Considerations
5.1
Thermal Specifications
The processor incorporates three methods of monitoring die temperature: the digital
thermal sensor, Intel Thermal Monitor and the thermal “diode.” The Intel Thermal
Monitor (detailed in
) must be used to determine when the maximum
specified processor junction temperature has been reached.
5.1.1
Thermal Diode
The processor incorporates an on-die PNP transistor whose base emitter junction is
used as a thermal diode, with its collector shorted to Ground. The thermal diode can be
read by an off-die analog/digital converter (a thermal sensor) located on the
motherboard or a stand-alone measurement kit. The thermal diode may be used to
monitor the die temperature of the processor for thermal management or
instrumentation purposes but is not a reliable indication that the maximum operating
temperature of the processor has been reached. When using the thermal diode, a
temperature offset value must be read from a processor Model Specific Register (MSR)
and applied. See
for more details. Please see
for thermal
diode usage recommendation when the PROCHOT# signal is not asserted.
Note:
The reading of the external thermal sensor (on the motherboard) connected to the
processor thermal diode signals will not necessarily reflect the temperature of the
hottest location on the die. This is due to inaccuracies in the external thermal sensor,
on-die temperature gradients between the location of the thermal diode and the hottest
location on the die, and time based variations in the die temperature measurement.
Time based variations can occur when the sampling rate of the thermal diode (by the
thermal sensor) is slower than the rate at which the T
J
temperature can change.
Offset between the thermal diode based temperature reading and the Intel Thermal
Monitor reading may be characterized using the Intel Thermal Monitor’s Automatic
mode activation of the thermal control circuit. This temperature offset must be taken
into account when using the processor thermal diode to implement power management
events. This offset is different than the diode Toffset value programmed into the
processor MSR.
through
provides the diode interface and specifications. Two different
sets of diode parameters are listed in
. The diode model
parameters apply to the traditional thermal sensors that use the diode equation to
determine the processor temperature. Transistor model parameters have been added
to support thermal sensors that use the transistor equation method. The Transistor
model may provide more accurate temperature measurements when the diode ideality
factor is closer to the maximum or minimum limits. Please contact your external sensor
supplier for their recommendation. The thermal diode is separate from the Intel
Thermal Monitor’s thermal sensor and cannot be used to predict the behavior of the
Intel Thermal Monitor.
5.1.2
Thermal Diode Offset
In order to improve the accuracy of the diode based temperature measurements, a
temperature offset value (specified as Toffset) will be programmed in the processor
Model Specific Register (MSR) which will contain thermal diode characterization data.
During manufacturing each processor thermal diode will be evaluated for its behavior
relative to the theoretical diode. Using the equation above, the temperature error
created by the difference n
trim
and the actual ideality of the particular processor will be
calculated.