Intel MPCMM0001 manual Power and Hot Swap Management, Hot Swap States, FRU Insertion

Power and Hot Swap Management
Power and Hot Swap Management	7

The CMM is responsible for the management of FRU hot-swap activities. The CMM listens to FRU hot-swap SEL messages from IPMI devices and distributes power to each FRU after negotiating with the respective IPMI device fronting the FRU. The CMM also manages the shelf- wide power budget. The CMM also polls IPMI devices to get the status of each FRU fronted by the IPMI device. The CMM uses shelf FRU information to guarantee power-up sequence delays between boards.

Once the CMM receives the shelf FRU information on power budget and power sequence delays, it is ready to service FRU hot-swap requests from respective IPMI devices.

7.1Hot Swap States

The CMM defines the hot swap status of a FRU as being in one of eight states. CMM documentation often refers to only the letter/number designation of that state (M0 - M7). Here is a list of what each of those states means:

•"State M0 - Not Installed"

•"State M1 - Inactive"

•"State M2 - Activation Request"

•"State M3 - Activation In Progress"

•"State M4 - Active"

•"State M5 - Deactivation Request"

•"State M6 - Deactivation In Progress"

•"State M7 - Communication Lost"

7.2FRU Insertion

When the CMM receives a request that a FRU is ready to activate, it will compute the FRU’s power, get the power levels, and check the available power budget.

The Set_Power_Level command will be sent only when the necessary power budget, from each of the redundant power feeds, is available to satisfy FRU's desired power level. If a FRU can't be activated at the time of the request, it should remain in the M3 state and shall be powered up when the necessary power budget becomes available. If the FRU decides to operate at a lower power level and notifies the Shelf Manager and the new power level is within the current Shelf Power envelope, the CMM shall send the Set_Power_Level (new desired level) command to the FRU.

7.3Graceful FRU Extraction

When the CMM receives a FRU Hot swap request for extraction, the CMM will send the deactivate state command, and the FRU will transition to M6 state and begin its shut-down procedures. Once the FRU has shut down, it transitions to M1 state, and the CMM then reclaims the FRU’s power and adjusts the power budget for the newly available power.

68MPCMM0001 Chassis Management Module Software Technical Product Specification