Processor Thermal Monitoring And Regulation; Digital Thermal Sensor (Dts); Thermal Diode Sensor; Thermal Monitor 1 (Tm1) - Kontron CP308 User Manual

Thermal Considerations
6.2

Processor Thermal Monitoring and Regulation

The Intel® Core™2 Duo processor includes the following on-die temperature sensors:
• Two Digital Thermal Sensors (DTS)

• Thermal Diode Sensor

• Thermal Monitor 1 (TM1) Sensor
• Thermal Monitor 2 (TM2) Sensor
• Catastrophic Cooling Failure Sensor
Via the Thermal Diode Sensor, the System Management Controller can measure the processor
die temperature. Via the Digital Thermal Sensor (DTS), the application software can measure
the processor die temperature.
The Thermal Monitor 1 (TM1) Sensor, the Thermal Monitor 2 (TM2) Sensor, and the Cata-
strophic Cooling Failure Sensor are not accessible. They serve for protecting the processor
from overheating. These sensors are integrated in the processor and work without any interop-
erability of the System Management Controller, the uEFI BIOS or the software application. The
thermal monitor function utilizes the thermal control circuit to regulate the processor tempera-
ture. It is enabled in the uEFI BIOS and allows the processor to maintain a safe operating tem-
perature without the need for special software drivers or interrupt handling routines.
The maximum die temperature for all processors used on the CP308 is 105°C.
6.2.1

Digital Thermal Sensor (DTS)

The processor includes two on-die Digital Thermal Sensors (DTS) that can be read via an in-
ternal register of the processor (no I/O interface). The Digital Thermal Sensors provide the pre-
ferred method of reading the processor die temperature since they are located much closer to
the hottest portions of the die and can thus more accurately track the die temperature.
The values measured at the Digital Thermal Sensors (DTS) may not correspond to the values
measured at the Thermal Diode Sensor since the Thermal Diode Sensor is located elsewhere
on processor die.
6.2.2 Thermal Diode Sensor
The processor includes one Thermal Diode Sensor used by the System Management Control-
ler to measure the processor die temperature.
6.2.3

Thermal Monitor 1 (TM1)

The Thermal Monitor 1 (TM1) Sensor controls the processor temperature and power consump-
tion by activating the Thermal Control Circuit (TCC) when the processor silicon reaches its
maximum operating temperature (105°C).
When TM1 is enabled and a high temperature situation exists, the processor clock is modulat-
ed by alternatively turning the clocks off and on. Once the temperature has dropped below the
maximum operating temperature, the Thermal Control Circuit goes inactive.
The temperature at which TM1 activates the Thermal Control Circuit is neither user-config-
urable nor software-visible.
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CP308
ID 1027-4487, Rev. 3.0