Smbus Monitoring Interface - Intel SC5300BRP Technical Product Specification

Intel® Server Chassis SC5300 5U Kit TPS
3.3.5.1 PSON# Input and Output Signals
The PSON# signal is required to remotely turn on/off the power supply.
3.3.5.2 PSKILL
The purpose of the PSKill pin is to allow for hot swapping of the power supply. The mating pin of
this signal on the power distribution board input connector should be tied to ground, and its
resistance shall be less than 5 ohms.
3.3.5.3 PWOK (Power OK) Input and Output Signals
PWOK is a Power Good, 5V TTL compatible, coming from the power supply, active HI logic
signal, which will be pulled HIGH by the power supply to indicate that its +12V output is within
its regulation limits. When its +12V output voltage falls below regulation limits or when AC
power has been removed for a time sufficiently long so that power supply operation is no longer
guaranteed, PWOK will be de-asserted to a LOW state.
3.3.5.4 lert# Output Signal
This signal indicates that the power supply is experiencing a problem that the user should
investigate. This signal from each supply is OR-ed on the power distribution board, and then
becomes one PSALERT# output signal to the system. See the power supply specification for
signal description details.
3.4

SMBus Monitoring Interface

The 600-W and 730-W power supplies are compatible with both SMBus 2.0 'high power' and
2
I C Vdd based power and drive. This bus operates at 3.3V. The SMBus pull-ups are located on
the server board.
The SMBus provides power monitoring, failure conditions, warning conditions, and FRU data.
Two pins have been reserved on the connector to provide this information. One pin is the Serial
Clock (PSM Clock). The second pin is used for Serial Data (PSM Data). Both pins are bi-
directional and are used to form a serial bus.
There are two usage models depending on the system. The system shall control the usage
model by setting the Usage Mode bit.
Default Mode: In this mode, the LEDs and registers must automatically clear when a warning
event has occurred, because there is no software, BIOS, or other agent that will access the
power supply via the SMBus to do any clearing.
Intelligent Mode: A system management controller or BIOS agent exists that can read and clear
status. In this mode, the LEDs and registers should latch when a warning event occurs so that
the system and user can read their status before it changes during transient events. There
should also be a mechanism to allow the system management or BIOS to 'force' the LED states
in order to identify which power supply should be replaced.
Critical events will cause the power supply to shutdown and latch the LED and SMBAlert signal
no matter what mode the power supply is in; "default" or Intelligent."
Revision 1.31
Chassis Power Subsystem
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