Datasheet
67
Thermal Management
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 recommended
.
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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.
An external thermal sensor with a serial interface may be placed next to a SO-DIMM (or
any other appropriate platform location), or a remote Thermal Diode may be placed
next to the SO-DIMM (or any other appropriate platform location) and connected to the
external Thermal Sensor.
Additional external thermal sensor's outputs, for multiple sensors, can be wire-OR'd
together allow signaling from multiple sensors that are physically located separately.
Software can, if necessary, distinguish which SO-DIMM(s) is the source of the overtemp
through the serial interface. However, since the SO-DIMM's is located on the same
Memory Bus Data lines, any integrated graphics and memory controller-based read
throttle will apply equally.
Thermal sensors can either be directly routed to the integrated graphics and memory
controller PM_EXT_TS#[0] and PM_EXT_TS#[1] pins or indirectly routed to integrated
graphics and memory controller by invoking an Embedded Controller (EC) connected in
between the thermal sensor and integrated graphics and memory controller pins. Both
routing methods are applicable for both thermal sensors placed on the motherboard
(TS-on-Board) and/or thermal sensors located on the memory modules (TS-on-DIMM).
5.2.2.4
THERMTRIP# Operation
The integrated graphics and memory controller can assert THERMTRIP# (Thermal Trip)
to indicates that its junction temperature has reached a level beyond which damage
may occur. Upon assertion of THERMTRIP#, the integrated graphics and memory
