Intel 2 Extreme X7900 LF80537GG0724ML Manuale Utente

86

Datasheet

junction temperature within the maximum specification, the system must initiate an 

orderly shutdown to prevent damage. If the processor enters one of the above low 

power states with PROCHOT# already asserted, PROCHOT# will remain asserted until 

the processor exits the low power state and the processor junction temperature drops 

below the thermal trip point. 

If Intel Thermal Monitor automatic mode is disabled, the processor will be operating out 

of specification. Regardless of enabling the automatic or on-demand modes, in the 

event of a catastrophic cooling failure, the processor will automatically shut down when 

the silicon has reached a temperature of approximately 125°C. At this point the 

THERMTRIP# signal will go active. THERMTRIP# activation is independent of processor 

activity and does not generate any bus cycles. When THERMTRIP# is asserted, the 

processor core voltage must be shut down within the time specified in 

.

In all cases the Intel Thermal Monitor feature must be enabled for the processor to 

remain within specification.

The processor also contains an on die Digital Thermal Sensor (DTS) that can be read 

via an MSR (no I/O interface). Each core of the processor will have a unique digital 

thermal sensor whose temperature is accessible via the processor MSRs. The DTS is the 

preferred method of reading the processor die temperature since it can be located 

much closer to the hottest portions of the die and can thus more accurately track the 

die temperature and potential activation of processor core clock modulation via the 

Intel Thermal Monitor. The DTS is only valid while the processor is in the normal 

operating state (the Normal package level low power state).

Unlike traditional thermal devices, the DTS will output a temperature relative to the 

maximum supported operating temperature of the processor (T

J,max

). It is the 

responsibility of software to convert the relative temperature to an absolute 

temperature. The temperature returned by the DTS will always be at or below T

J,max

. 

Catastrophic temperature conditions are detectable via an Out Of Spec status bit. This 

bit is also part of the DTS MSR. When this bit is set, the processor is operating out of 

specification and immediate shutdown of the system should occur. The processor 

operation and code execution is not guaranteed once the activation of the Out of Spec 

status bit is set.

The DTS-relative temperature readout corresponds to the 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 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 because 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 Architectures Software 

Developer’s Manual for specific register and programming details.