Intel i5-2520M FF8062700840017 User Manual

Datasheet

61

The DTS-relative temperature readout directly impacts the Adaptive Thermal Monitor 

trigger point. When a DTS indicates that the maximum processor core temperature has 

been reached (a reading of 0 x 0 on any core), the TCC will activate and indicate a 

Adaptive Thermal Monitor event. 

Changes to the temperature can be detected via two programmable thresholds located 

in the processor thermal MSRs. These thresholds have the capability of generating 

interrupts via the core's local APIC. Refer to the Intel® 64 and IA-32 Architectures 

Software Developer's Manuals for specific register and programming details.

PROCHOT# (processor hot) is asserted when the processor core temperature has 

reached its maximum operating temperature (T

j,max

). This will activate the TCC and 

signal a thermal event which is then resolved by the Adaptive Thermal Monitor. See 

 (above) for a timing diagram of the PROCHOT# signal assertion relative to 

the Adaptive Thermal Response.

 

Only a single PROCHOT# pin exists at a package level 

of the processor. When any core arrives at the TCC activation point, the PROCHOT# 

signal will be driven by the processor core. PROCHOT# assertion policies are 

independent of Adaptive Thermal Monitor enabling.

Bus snooping and interrupt latching are active while the TCC is active.

By default, the PROCHOT# signal is defined as an output only. However, the signal may 

be configured as bi-directional. When configured as a bi-directional signal, PROCHOT# 

can be used for thermally protecting other platform components should they overheat 

as well. When PROCHOT# is signaled externally:

• the processor core will immediately reduce processor power to the minimum 

voltage and frequency supported. This is contrary to the internally-generated 

Adaptive Thermal Monitor response. 

• Clock modulation is not activated. 

The TCC will remain active until the system deasserts PROCHOT#. The processor can 

be configured to generate an interrupt upon assertion and deassertion of the 

PROCHOT# signal. 

PROCHOT# may be used for thermal protection of voltage regulators (VR). System 

designers can create a circuit to monitor the VR temperature and activate the TCC 

when the temperature limit of the VR is reached. By asserting PROCHOT# (pulled-low) 

and activating the TCC, the VR will cool down as a result of reduced processor power 

consumption. Bi-directional PROCHOT# can allow VR thermal designs to target thermal 

design current (I

TDC

) instead of maximum current. Systems should still provide proper 

cooling for the VR and rely on bi-directional PROCHOT# only as a backup in case of 

system cooling failure. Overall, the system thermal design should allow the power 

delivery circuitry to operate within its temperature specification even while the 

processor is operating at its TDP.

With a properly designed and characterized thermal solution, it is anticipated that 

PROCHOT# will only be asserted for very short periods of time when running the most 

power intensive applications. The processor performance impact due to these brief 

periods of TCC activation is expected to be so minor that it would be immeasurable.