Kontron RTM8940 - Manual (Page 21)

8 RTM8940
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• 2 ETSI T3 E1/T1 BITS input/outputs
• 2 ETSI T4 E1/T1 Upstream/Downstream Chassis Clock Support.
2.6 MMC Boot Block
The MMC runs a firmware from its internal 256KB flash. It is programmed by an additional 8K boot block. It
keeps the last two copies of the MMC firmware in dedicated flash memories. The boot block activates the MMC
image and can rollback a firmware update in the MMC in case of problems.
2.7 Hardware Management Overview
The RTM communicates with the front board using the IPMB-L channel. Kontron Intelligent RTM address on
the IPMB-L is fixed and has a value of 0xA6.
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
nonvolatile memory on an EEPROM connected via a local I2C interface to the MMC. It is possible to store up to
4 KBytes within the FRU inventory information. Event generation over IPMB-L bus to reach the front board
that forward it to the ShMc ensure that 'post-mortem' logging information is available even if the power of
the RTM is disabled.
The onboard DC voltages and temperature are monitored by the MMC device. The MMC will send an event to
the front board if any of the thresholds are exceeded.
To increase the reliability of the RTM8940 management subsystem, an external watchdog supervisor for the
MMC is implemented. The MMC must strobe the external watchdog at 500 μsec. intervals to ensure continuity
of operation of the board's management subsystem. If the MMC ceases to strobe the watchdog supervisor,
the watchdog resets the MMC. The watchdog timeout expires after one second if strobes are not received. The
external watchdog supervisor is not configurable and must not be confused with the IPMI v1.5 watchdog
timer commands. This external watchdog of the MMC is implemented in a separate chip.
2.7.1 Sensor Data Record (SDR)
Every sensor on the RTM is associated with a Sensor Data Record (SDR). Sensor Data Records contain
information about the sensors identification such as sensor type, sensor name and sensor unit. The SDR also
contains the configuration of a specific sensor such as threshold/hystheresis and event generation
capabilities that specifies sensor behaviour. Some fields of the SDR are configurable through IPMI v1.5
command and are set with built-in initial values. Finally, one field which is the sensor owner must reflect the
module addresses that allows a system management software to identify the owner of the SDR when it is
scanned from the front board IPMC and merged within the IPMC Device SDR repository.
From IPMI prespective, the RTM8940 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 to
merge the hot swaped RTM sensor with the front board sensors population. The usual way the SHMC is