Intel BX80633I74960X, CM8064601466200, CM8064601466003, BX80637I73770K manual PROCHOT# Signal

Thermal Management—Processor

If TM1 and TM2 have both been active for greater than 20 ms and the processor temperature has not dropped below the TCC activation point, the Critical Temperature Flag in the IA32_THERM_STATUS MSR will be set. This flag is an indicator of a catastrophic thermal solution failure and that the processor cannot reduce its temperature. Unless immediate action is taken to resolve the failure, the processor will probably reach the Thermtrip temperature (see Testability Signals on page 87) within a short time. To prevent possible permanent silicon damage, Intel recommends removing power from the processor within ½ second of the Critical Temperature Flag being set.

PROCHOT# Signal

An external signal, PROCHOT# (processor hot), is asserted when the processor core temperature has exceeded its specification. If Adaptive Thermal Monitor is enabled (it must be enabled for the processor to be operating within specification), the TCC will be active when PROCHOT# is asserted.

The processor can be configured to generate an interrupt upon the assertion or de- assertion of PROCHOT#.

By default, the PROCHOT# signal is set to bi-directional. However, it is recommended to configure the signal as an input only. When configured as an input or bi-directional signal, PROCHOT# can be used for thermally protecting other platform components should they overheat as well. When PROCHOT# is driven by an external device:

•The package will immediately transition to the minimum operation points (voltage and frequency) supported by the processor and graphics cores. This is contrary to the internally-generated Adaptive Thermal Monitor response.

•Clock modulation is not activated.

The TCC will remain active until the system de-asserts PROCHOT#. The processor can be configured to generate an interrupt upon assertion and de-assertion of the PROCHOT# signal. Refer to the appropriate Platform Thermal Mechanical Design Guidelines (see Related Doucments section) for details on implementing the bi- directional PROCHOT# feature.

Note: Toggling PROCHOT# more than once in 1.5 ms period will result in constant Pn state of the processor.

Note: A corner case exists for PROCHOT# configured as a bi-directional signal that can cause several milliseconds of delay to a system assertion of PROCHOT# when the output function is asserted.

As an output, PROCHOT# (Processor Hot) will go active when the processor temperature monitoring sensor detects that one or more cores has reached its maximum safe operating temperature. This indicates that the processor Thermal Control Circuit (TCC) has been activated, if enabled. As an input, assertion of PROCHOT# by the system will activate the TCC for all cores. TCC activation when PROCHOT# is asserted by the system will result in the processor immediately transitioning to the minimum frequency and corresponding voltage (using Frequency control). Clock modulation is not activated in this case. The TCC will remain active until the system de-asserts PROCHOT#.

Use of PROCHOT# in input or bi-directional mode can allow VR thermal designs to target maximum sustained current instead of maximum current. Systems should still provide proper cooling for the Voltage Regulator (VR), and rely on PROCHOT# only as

Desktop 4th Generation Intel® Core™ Processor Family, Desktop Intel® Pentium® Processor Family, and Desktop Intel® Celeron® Processor Family

December 2013	Datasheet – Volume 1 of 2
Order No.: 328897-004	77