82598EB Datasheet, PDF (531/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - Advanced Workflows
Assuming the MC needs to share the NC-SI bus between packages the MC should:
1. Define a time-slot for each device.
2. Discover, initialize, and configure all the NC packages and channels.
3. Issue a De-Select Package command to all the channels.
4. Set active_package to 0x0 (or the lowest existing package ID).
5. At the beginning of each time slot the MC should:
a. Issue a De-Select Package to the active_package. The MC must then wait for a response and
then an additional timeout for the package to become de-selected (200 s). See the NC-SI
specification table 10 - parameter NC Deselect to Hi-Z Interval.
b. Find the next available package (typically active_package = active_package + 1).
c. Issue a Select Package command to active_package.
5.4.5.2 External Link Control
The MC can use the NC-SI Set Link command to control the external interface link settings. This
command enables the MC to set the auto-negotiation, link speed, duplex, and other parameters.
This command is only available when the host OS is not present. Indicating the host OS status can be
obtained via the Get Link Status command and/or Host OS Status Change AEN command.
Recommendation:
• Unless explicitly needed, it is not recommended to use this feature. The NC-SI Set Link command
does not expose all the possible link settings and/or features. This might cause issues under
different scenarios. Even if decided to use this feature, it is recommended to use it only if the link
is down (trust the 82598EB until proven otherwise).
• It is recommended that the MC first query the link status using the Get Link Status command.
The MC should then use this data as a basis and change only the needed parameters when
issuing the Set Link command.
For further details, refer to the NC-SI specification.
5.4.5.2.1 Set Link While LAN PCIe Functionality is Disabled
In cases where a LAN device is used solely for manageability and its LAN PCIe function is disabled,
using the NC-SI Set Link command while advertising multiple speeds and enabling auto-negotiation
results in the lowest possible speed chosen.
To enable link of higher a speed, the MC should not advertise speeds that are below the desired link
speed, as the lowest advertised link speed is chosen.
When the LAN device is only used for manageability and the link speed advertisement is configured by
the MC, changes in the power state of the LAN device is not effected and the link speed is not re-
negotiated by the LAN device.
5.4.5.3 Multiple Channels (Fail-Over)
In order to support a fail-over scenario, it is required from the MC to operate two or more channels.
These channels might or might not be in the same package.
The key element of a fault-tolerance fail-over scenario is having two (or more) channels identifying to
the switch with the same MAC address, but only one of them being active at any given time (such as
switching the MAC address between channels).
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