Processor—Thermal Management

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 bidirectional 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 a backup in case of system cooling failure. The system thermal design should allow the power delivery circuitry to operate within its temperature specification even while the processor is operating at its Thermal Design Power.

5.7THERMTRIP# Signal

Regardless of whether or not Adaptive Thermal Monitor is enabled , in the event of a catastrophic cooling failure, the processor will automatically shut down when the silicon has reached an elevated temperature (refer to the THERMTRIP# definition in

Intel® Xeon® Processor E3-1200 v3 Product Family

 

Datasheet – Volume 1 of 2

June 2013

72

Order No.: 328907-001