Intel S4600LT2, Technical Product Specification

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Intel® Intelligent Power Node Manager (NM) Intel® Server System R2000LH2/T2 Product Family TPS
Revision 1.0 96
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BMC initializes ME-owned sensors based on SDRs.
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BMC receives platform event messages sent by the ME.
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BMC notifies ME of POST completion.
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BMC may be queried by the ME for inlet temperature readings.
13.1.10 SmaRT/CLST
The power supply optimization provided by SmaRT/CLST relies on a platform HW capability as
well as ME FW support. When a PMBus-compliant power supply detects insufficient input
voltage, an overcurrent condition, or an over-temperature condition, it will assert the SMBAlert#
signal on the power supply SMBus (a.k.a. the PMBus). Through the use of external gates, this
results in a momentary assertion of the PROCHOT# and MEMHOT# signals to the processors,
thereby throttling the processors and memory. The ME FW also sees the SMBAlert# assertion,
queries the power supplies to determine the condition causing the assertion, and applies an
algorithm to either release or prolong the throttling, based on the situation.
System power control modes include:

SmaRT: Low AC input voltage event; results in a onetime momentary throttle for each
event to the maximum throttle state.
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Electrical Protection CLST: High output energy event; results in a throttling hiccup mode
with fixed maximum throttle time and a fix throttle release ramp time.
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Thermal Protection CLST: High power supply thermal event; results in a throttling hiccup
mode with fixed maximum throttle time and a fix throttle release ramp time.
When the SMBAlert# signal is asserted, the fans will be gated by HW for a short period
(~100ms) to reduce overall power consumption. It is expected that the interruption to the fans
will be of short enough duration to avoid false lower threshold crossings for the fan tach
sensors; however, this may need to be comprehended by the fan monitoring FW if it does have
this side-effect.
13.1.10.1 Dependencies on PMBus-compliant Power Supply Support
The SmaRT/CLST system feature depends on functionality present in the ME NM SKU. This
feature requires power supplies that are compliant with the
PMBus Specification rev1.2 .