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aTCA-80606PA
3.6 Intelligent Platform Management Bus (IPMB)
The Shelf uses an Intelligent Platform Management Bus (IPMB) for management
communications among all ATCA Boards and the Shelf Managers. The reliability of the
IPMB is improved by the addition of a second IPMB, with the two IPMBs referenced as
IPMB-A and IPMB-B.
IPMB-A and IPMB-B are routed to the ATCA Slots in a bused configuration.
Figure 2: Bused IPMB
3.7 Shelf SEEPROM
The SEEPROMs are located at the rear side of the backplane. The Shelf SEEPROM is a
repository of the shelf-specific information, capabilities of the system and other user
configurable options.
The SEEPROM contains as example:
•
A list of which slots are connected together
•
How the update channels are routed
•
How many slots are in the system
•
What the maximum power is to each slot
•
The serial number of the Shelf
•
The backplane topology etc.
The Shelf Managers use this information to provide functions such as electronic keying,
controlling the power state of the system, etc.
The Shelf Managers cache the information that is stored in the SEEPROMs so that the
SEEPROM is only needed when the Shelf Managers are first inserted or when the Shelf is
first turned on.
The redundant SEEPROMs ensure that if one is corrupt or non-functional, the second can
provide the necessary information. The Shelf Manager selects what set of information is
correct and then synchronizes the two SEEPROMs from the internally cached of the
SEEPROM information.
