Thermal Management Logic and Thermal Monitor Feature
Thermal and Mechanical Design Guidelines 39
4.2.10 Digital Thermal Sensor
The IntelÂ® Coreâ„¢2 Duo desktop processor E6000/E4000 sequence introduces the
Digital Thermal Sensor (DTS) as the on-die sensor to use for fan speed control (FSC).
The DTS will eventually replace the on-die thermal diode used in pervious products.
The IntelÂ® Coreâ„¢2 Duo desktop processor E6000/E4000 sequences will have both the
DTS and thermal diode enabled. 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).
The DTS can be accessed by two methods. The first is via a MSR. The value read via
the MSR is an unsigned number of degrees C away from TCC activation. The second
method which is expected to be the primary method for FSC is via the PECI interface.
The value of the DTS when read via the PECI interface is always negative and again is
degrees C away from TCC activation.
A TCONTROL value will be provided for use with DTS. The usage model for TCONTROL with
the DTS is the same as with the on-die thermal diode:
• If the Digital thermal sensor is less than TCONTROL, the fan speed can be reduced.
• If the Digital thermal sensor is greater than or equal to TCONTROL, then TC must be
maintained at or below the Thermal Profile for the measured power dissipation.
The calculation of TCONTROL is slightly different from previous product. There is no base
value to sum with the TOFFSET located in the same MSR as used in previous processors.
The BIOS only needs to read the TOFFSET MSR and provide this value to the fan speed
Figure 9. TCONTROL for Digital Thermal Sensor
Digital Thermometer Temperature
Thermal Diode Temperature
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.
Note: IntelÂ® Coreâ„¢2 Duo processor E6000 and E4000 sequences do not have an on-die
thermal diode. The TCONTROL in the MSR is relevant only to the DTS.
and we wonder how to measure accurately