Digital Thermal Sensor; Figure 9. T For Digital Thermometer - Intel Q9450 - Core 2 Quad Quad-Core Processor Design Manual

Thermal Management Logic and Thermal Monitor Feature
4.2.9

Digital Thermal Sensor

Multiple digital thermal sensors can be implemented within the package without
adding a pair of signal pins per sensor as required with the thermal diode. The digital
thermal sensor is easier to place in thermally sensitive locations of the processor than
the thermal diode. This is achieved due to a smaller foot print and decreased
sensitivity to noise. Since the DTS is factory set on a per-part basis there is no need
for the health monitor components to be updated at each processor family.
The processor uses the Digital Thermal Sensor (DTS) as the on-die sensor to use for
fan speed control (FSC). The DTS replaces the on-die thermal diode used in previous
product. The DTS is monitoring the same sensor that activates the TCC
(see Section 4.2.2). Readings from the DTS are relative to the activation of the TCC.
The DTS value where TCC activation occurs is 0 (zero).
A T
CONTROL
the DTS is the same as with the on-die thermal diode:
 If the Digital Thermometer is less than T
 If the Digital Thermometer is greater than or equal to T
maintained at or below the Thermal Profile for the measured power dissipation.
The calculation of T
value to sum with the T
The BIOS only needs to read the T
control device.
Figure 9. T for Digital Thermometer
CONTROL
Thermal Diode Temperature Thermal Diode Temperature
70 70 70 70 70 70
60 60 60 60 60 60
50 50 50 50 50 50
40 40 40 40 40 40
30 30 30 30 30 30
20 20 20 20 20 20
10 10 10 10 10 10
Note: The processor does not have an on-die thermal diode. The T
relevant only to the DTS.
Thermal and Mechanical Design Guidelines
value will be provided for use with DTS. The usage model for T
is slightly different from previous product. There is no base
CONTROL
located in the same MSR as used in previous processors.
OFFSET
Temperature Temperature Temperature Temperature
the fan speed can be reduced.
CONTROL,
MSR and provide this value to the fan speed
OFFSET
Digital Thermometer Temperature Digital Thermometer Temperature
Power Power
Power Power
Fan Speed Fan Speed Fan Speed Fan Speed
Time Time Time Time
with
CONTROL
then T must be
CONTROL, C
0 0 0 0 0 0
20 20 20 20 20 20
30 30 30 30 30 30
40 40 40 40 40 40
50 50 50 50
50 50
60 60 60 60 60 60
70 70 70 70 70 70
in the MSR is
CONTROL
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