At8902 software description – Kontron AT8902 User Manual
Page 80
AT8902
Software Description
Page 4 - 13
AT8902 User Guide
4.4.1.1
IPMB Link Sensor
The AT8902 provides two IPMB links to increase communication reliability to the shelf manager
and other IPM devices on the IPMB. These IPMB links work together for increased throughput
where both busses are actively used for communication at any time. A request might be re-
ceived over IPMB Bus A, and the response is sent over IPMB Bus B. Any requests that time
out are retried on the redundant IPMB bus. In the event of any link state change, the events are
written to the AT8902 SEL. The IPMC monitors the bus for any link failure and isolates itself
from the bus if it detects that it is causing errors on the bus. Events are sent to signal the failure
of a bus or, conversely, the recovery of a bus.
4.4.1.2
FRU Hot Swap
The hot swap event message conveys the current state of the FRU, the previous state, and a
cause of the state change as can be determined by the IPMC. Refer to PICMG 3.0 Specifica-
tions for further details on the hot swap state.
4.4.1.3
Fabric Presence Sensor
The FPS indicates if an optional Extension Fabric Mezzanine is present.
4.4.1.4
CPU Status
The CPU Status is set if the PPC experiences a machine check error.
4.4.1.5
POSTCODE
The IPMC has access to the POSTCODE registers in the CPLD. Refer to chapter 4.3.1.2 (Boot
Steps).
4.4.1.6
Health Error
The Health Error is asserted if one of the sensors in Table 4-3: (AT8902 sensors) matches the
Health LED/Sensor condition.
Ver change
discrete
On/Off
No change
Table 4-3: AT8902 sensors (continued)
IPMI Sensor Name
Unit
Scanning Enabled Under
Power State
Health LED/Sensor