Board Features
13
Please note that during FWUM firmware upgrade the MMC is held in reset.
2.7.7.1
Hot-Swap Process
The RTM8020 has the ability to be hot-swapped in and out of a carrier. The onboard MMC manages
the RTM's power-up and power-down transitions. The list below illustrates this process for power
down request.
1 Ejector latch is opened. HOT_SWAP_PB# assertion. MMC firmware detects the assertion of this signal.
2 MMC sends "Module Handle Open" event message to RTM Carrier. The corresponding M state of RTM
Carrier moves from M4-> M5.
3 RTM Carrier moves from M5 -> M6 if the SHMC grants the request and then sends the FRU Control
requesting quiesced state to the RTM.
4 The firmware deasserts payload power and sends "Module Quiesced" event message to the RTM Carrier
where it transitions from M6 to M1 state.
2.7.7.2
Hot-Swap LED
The RTM8020 supports a blue Hot Swap LED mounted on the front panel. This LED indicates when it
is safe to remove the RTM from the Carrier. The on-board MMC drives this LED to indicate the hot-
swap state. The following states are possible:
When the RTM latch is disengaged from the faceplate, the hot swap switch embedded in the PCB will
assert a "HOT_SWAP_PB#" signal to the MMC, and the MMC will send “Module Handle Open” event
message to the RTM which moves from the M4 state to the M5 state. At the M5 state, the RTM Carrier
will ask the SHMC (or Shelf Manager) for permission to move the RTM to the M6 state. Then the RTM
will set the RTM Hot Swap LED to indicate this state with a short blink. Once permission is received
from the SHMC or higher-level software, the RTM carrier will move to the M6 state.
The SHMC or higher level software can reject the request to move to the M6 state. If this occurs, the
RTM will returns the Hot Swap LED to a solid off condition, indicating that the RTM has returned to
M4 state.
If the RTM reaches the M6 state through an extraction request through the RTM handle latch, the
MMC communicates to the RTM Carrier that the module must discontinue operation in preparation
for removal. The Hot Swap LED continues to flash during this preparation time, just like it does at
LED state
Description
OFF
RTM is in M4 state, normal state when board is in operation.
ON
Ready for hot swap.
Short blink
M5 state deactivation request
Long blink
M2 state Activation Request.
