Intel 2 Duo L7200 LE80537LF0144M User Manual

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Datasheet

The Digital Thermal Sensor (DTS) relative temperature readout corresponds to the 

Intel Thermal Monitor (Intel Thermal Monitor 1/Intel Thermal Monitor 2) trigger point. 

When the DTS indicates maximum processor core temperature has been reached the 

Intel Thermal Monitor 1 or Intel Thermal Monitor 2 hardware thermal control 

mechanism will activate. The DTS and Intel Thermal Monitor 1/Intel Thermal Monitor 2 

temperature may not correspond to the thermal diode reading since the thermal diode 

is located in a separate portion of the die and thermal gradient between the individual 

core DTS. Additionally, the thermal gradient from DTS to thermal diode can vary 

substantially due to changes in processor power, mechanical and thermal attach and 

software application. The system designer is required to use the DTS to guarantee 

proper operation of the processor within its temperature operating specifications.

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

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

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

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

Overheat detection is performed by monitoring the processor temperature and 

temperature gradient. This feature is intended for graceful shut down before the 

THERMTRIP# is activated. If the processor’s Intel Thermal Monitor 1 or Intel Thermal 

Monitor 2 are triggered and the temperature remains high, an “Out Of Spec” status and 

sticky bit are latched in the status MSR register and generates thermal interrupt. 

An external signal, PROCHOT# (processor hot), is asserted when the processor die 

temperature has reached its maximum operating temperature. If the Intel Thermal 

Monitor 1 or Intel Thermal Monitor 2 is enabled (note that the Intel Thermal Monitor 1 

or Intel Thermal Monitor 2 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 deassertion of 

PROCHOT#. 

The processor implements a bi-directional PROCHOT# capability to allow system 

designs to protect various components from over-heating situations. The PROCHOT# 

signal is bi-directional in that it can either signal when the processor has reached its 

maximum operating temperature or be driven from an external source to activate the 

TCC. The ability to activate the TCC via PROCHOT# can provide a means for thermal 

protection of system components.

In a dual-core implementation, only a single PROCHOT# pin exists at a package level. 

When either core's thermal sensor trips, PROCHOT# signal will be driven by the 

processor package. If only Intel Thermal Monitor 1 is enabled, PROCHOT# will be 

asserted and only the core that is above TCC temperature trip point will have its core 

clocks modulated. If Intel Thermal Monitor 2 is enabled, then regardless of which 

core(s) are above TCC temperature trip point, both cores will enter the lowest 

programmed Intel Thermal Monitor 2 performance state.  It is important to note that 

Intel recommends both Intel Thermal Monitor 1 and Intel Thermal Monitor 2 to be 

enabled.

When PROCHOT# is driven by an external agent, if only Intel Thermal Monitor 1 is 

enabled on both cores, then both processor cores will have their core clocks modulated.  

If Intel Thermal Monitor 2 is enabled on both cores, then both processor core will enter 

the lowest programmed Intel Thermal Monitor 2 performance state.

One application is the 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