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Intel
®
Core
TM
2 Duo E6400, E4300, and Intel
®
Pentium
®
Dual-Core E2160 Processor
October 2007
TDG
Order Number: 315279 - 003US
31
Thermal Management Logic and Thermal Monitor Feature—Intel
®
Core
TM
2 Duo E6400, E4300,
and Intel
®
Pentium
®
Dual-Core E2160 Processor
power profile. Moreover, if a system is significantly under designed, there is a risk that
the Thermal Monitor feature will not be capable of maintaining a safe operating
temperature and the processor could shutdown and signal THERMTRIP#.
For information regarding THERMTRIP#, refer to the processor datasheet and to
Section 4.2.8
.
4.2.7
Operating System and Application Software Considerations
The Thermal Monitor feature and its thermal control circuit work seamlessly with ACPI
compliant operating systems. The Thermal Monitor feature is transparent to the
application software since the processor bus snooping, ACPI timer and interrupts are
active at all times.
4.2.8
THERMTRIP# Signal
In the event of a catastrophic cooling failure, the processor will automatically shut
down when the silicon temperature has reached its operating limit. At this point, the
system bus signal THERMTRIP# goes active and power must be removed from the
processor. THERMTRIP# activation is independent of processor activity and does not
generate any bus cycles. Refer to the processor datasheet for more information about
THERMTRIP#.
The temperature where the THERMTRIP# signal goes active is individually calibrated
during manufacturing. The temperature where THERMTRIP# goes active is roughly
parallel to the thermal profile and greater than the PROCHOT# activation temperature.
Once configured, the temperature at which the THERMTRIP# signal is asserted is
neither re-configurable nor accessible to the system.
4.2.9
Cooling System Failure Warning
It may be useful to use the PROCHOT# signal as an indication of cooling system failure.
Messages could be sent to the system administrator to warn of the cooling failure, while
the thermal control circuit would allow the system to continue functioning or allow a
normal system shutdown. If no thermal management action is taken, the silicon
temperature may exceed the operating limits, causing THERMTRIP# to activate and
shut down the processor. Regardless of the system design requirements or thermal
solution ability, the Thermal Monitor feature must still be enabled to ensure proper
processor operation.
4.2.10
Digital Thermal Sensor
The Intel® Core™2 Duo desktop processor E6000 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 previous products. The
processor will have both the DTS and thermal diode enabled. The DTS is monitoring the
same sensor that activates the TCC (Refer to
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.