Table of Contents
Advertisement
Thermal Management
Software has the ability to program the T
points should be selected with consideration for the thermal sensor accuracy and the
quality of the platform thermal solution. Overly conservative (unnecessarily low)
temperature settings may unnecessarily degrade performance due to frequent
throttling, while overly aggressive (dangerously high) temperature settings may fail to
protect the part against permanent thermal damage.
5.2.2.1.6
Hysteresis Operation
Hysteresis provides a small amount of positive feedback to the thermal sensor circuit to
prevent a trip point from flipping back and forth rapidly when the temperature is right
at the trip point. The digital hysteresis offset is programmable via processor registers.
5.2.2.2
Memory Thermal Throttling Options
The integrated graphics and memory controller has two, independent mechanisms that
cause system memory throttling:
TDP Controller: The TDP Controller is the main mechanism for limiting MCH power by
limiting memory bandwidth. Utilized as a thermal throttling mechanism, this feature is
triggered by the Hot temperature trip point of the Graphics and Memory Controller
digital thermal sensor (DTS) and initiates duty cycle throttling to delay memory
transactions and thereby reducing MCH power. Power reduction is memory
configuration and application dependant but duty cycle throttling intervals can be
customized for maximum throttling efficiency. The TDP Controller can also be used as a
bandwidth limiter using programmable memory read/write bandwidth thresholds. Intel
sets the default thresholds that will not restrict bandwidth and performance for most
applications but these thresholds can be modified to reduce MCH power regardless of
DTS temperature.
Note:
The TDP controller can be used as a closed loop thermal throttling (CLTT) mechanism or
an open loop thermal throttling (OLTT) mechanism, although CLTT is
•
DRAM Thermal Management: Ensures that the DRAM chips are operating within
thermal limits. The integrated graphics and memory controller can control the
amount of integrated graphics and memory controller-initiated bandwidth per rank
to a programmable limit via a weighted input averaging filter.
5.2.2.3
External Thermal Sensor Interface Overview
The integrated graphics and memory controller supports two inputs for external
thermal sensor notifications, based on which it can regulate memory accesses.
Note:
The thermal sensors should be capable of measuring the ambient temperature only and
should be able to assert PM_EXT_TS#[0] and/or PM_EXT_TS#[1] if the pre-
programmed thermal limits/conditions are met or exceeded.
Datasheet
, T
, and T
trip points, but these trip
cat
hot
aux
recommended.
65
Advertisement
Table of Contents
