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2.4
Hardware Management Overview
The AMC Carrier communicates with the Module Management Controller (MMC) using the IPMB-L channel.
The memory subsystem of the MMC consists of an integrated flash memory to hold the MMC operation code
and integrated RAM for data. The field replacement unit (FRU) inventory information is stored in the non
volatile memory on an EEPROM connected via a local I2C interface to the MMC microcontroller. It is possible
to store up to 4 KBytes within the FRU inventory information. Event generation over IPMB-L bus to reach the
AMC Carrier that forward it to the ShMc ensure that 'post-mortem' logging information is available even if
the power of the AMC is disabled.
The onboard DC voltages and temperature are monitored by the MMC device. The MMC will send an event to
the Carrier AMC if any of the thresholds are exceeded.
To increase the reliability of the SBC management subsystem, an external watchdog supervisor only for the
MMC is implemented. The MMC must strobe the external FWUM watchdog to ensure continuity of operation of
the board's management subsystem. The watchdog supervisor does not reset the payload power and the
restart of the MMC will not affect the payload and will restore the previous Module Hot Swap state. The
external watchdog supervisor is not configurable and must not be confused with the IPMI v1.5 watchdog
timer commands.
2.4.1
Sensor Data Record (SDR)
Every sensor on the AMC board is associated with a Sensor Data Record (SDR). Sensor Data Records contain
information about the sensors identification such as sensor type, sensor name, sensor unit. SDR also
contain the configuration of a specific sensor such as threshold/hystheresis, event generation capabilities
that specifies sensor behavior. Some field of the sensor SDR are configurable through IPMI v1.5 command
and are set to built-in initial value. Finally one field which is the sensor owner must reflect the module
addresses that allow the AMC Carrier to identify the owner of the SDR when it is scanned from the module
management controller and merged within the AMC Carrier Device SDR repository.
From IPMI perspective, the AMC management controller is set up as a satellite management controller (SMC).
It does support sensor devices, and use the IPMI static sensor population feature of IPMI v1.5. The usual way
the AMC Carrier is informed about an AMC insertion is through the AMC Module Hot Swap sensor via IPMB-L
event. All SDRs can be queried using Device SDR commands to the firmware. Module sensors that have been
implemented are listed below.
5
Board Features
AM450x User's Guide
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