Thermal Specifications; Thermal Features; Thermal Alert; Itanium ® 2 Processor Thermal Features - Intel Itanium 2 Processor Datasheet

5

Thermal Specifications

This chapter provides a description of the thermal features relating to the Itanium 2 processor.
5.1

Thermal Features

The Itanium 2 processor has an internal thermal circuit which senses when a certain temperature is
reached on the processor core. This circuit is used for controlling various thermal states. In
addition, an on-chip thermal diode is available for use by the thermal sensing device on the
Itanium 2 processor.
alert, enhanced thermal management (ETM), and thermal trip points.
Note: Figure 5-1
thermal state advances from one state to the next state when the cooling solution fails to control the
processor temperature, as this is affected by many factors such as cooling solution performance
degradation and processor workload variations.
Figure 5-1. Itanium
5.1.1

Thermal Alert

THRMALERT# is a programmable thermal alert signal which is part of the Itanium 2 processor
system management feature. THRMALERT# is asserted when the measured temperature from the
processor thermal diode equals or exceeds the temperature threshold data programmed in the high
temp (THIGH) or low temp (TLOW) registers on the sensor. Intel recommends using the upper
temperature reference byte listed in the Processor Information ROM when programming the
THIGH register (see
implement thermal regulation features such as generating an external interrupt to tell the operating
system that the processor core die temperature is increasing.
Datasheet
Figure 5-1 shows the relationship between temperature, time, and the thermal
is not intended to show a linear relationship in time or temperature as a processor's
®
2 Processor Thermal Features
Chapter 6 for more details). This signal can be used by the platform to
ETM
Thermal Alert
Time
Thermal Trip
000653b
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