82598EB Datasheet, PDF (434/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - SMBus Notification Methods
Vendor Specific ID: Four LSB bytes of the device Ethernet MAC Address. The device Ethernet address
is taken from words 0x2:0x0 in the EEPROM. Note that in 82598EB there are two MAC addresses (one
for each port). Bit 0 of the port 1 MAC address has the inverted value of bit 0 from the EEPROM.
1 Byte
MAC Address, Byte 3
MSB
1 Byte
MAC Address, Byte 2
1 Byte
MAC Address, Byte 1
1 Byte
MAC Address, Byte 0
LSB
5.3.4.2.3 SMBus ARP in Dual/Single Mode
The 82598EB operates in either single SMBus address mode or in dual SMBus address mode. These
modes reflect its SMBus ARP behavior.
While operating in single mode, the 82598EB presents itself on the SMBus as one device and only
responds to SMBus ARP as one device. In this case, 82598EB's SMBus address is SMBus address 0 as
defined in the EEPROM SMBus ARP address word. The 82598EB has only one AR and AV flag. The
vendor ID, the MAC address of the LAN's port, is taken from the port 0 address.
In dual mode, the 82598EB responds as two SMBus devices having two sets of AR/AV flags (one for
each port). The 82598EB responds twice to the SMBus ARP master, once each for each port. Both
SMBus addresses are taken from the SMBus ARP address word of the EEPROM. Note that the Unique
Device Identifier (UDID) is different between the two ports in the version ID field, which represents the
MAC address and is different between the two ports. It is recommended that the 82598EB first respond
as port 0, and only when the address is assigned, to start responding as port 1 to the Get UDID
command.
5.3.4.3 Concurrent SMBus Transactions
In single-address mode, concurrent SMBus transactions (receive, transmit and configuration read/
write) are allowed without limitation. Transmit fragments can be sent between receive fragments and
configuration Read/Write commands can also issue between receive and transmit fragments.
In dual-address mode, the same rules apply to concurrent traffic between the two addresses supported
by the 82598EB.
Note:
Packets can only be transmitted from one port/device at a given time. As a result, the BMC
must finish sent packets (send a last fragment command) from one port before starting the
transmission for the other port.
5.3.5 SMBus Notification Methods
The 82598EB supports three methods of notifying the BMC that it has information that needs to be read
by the BMC:
• SMBus alert
• Asynchronous notify
• Direct receive
The notification method that is used by the 82598EB can be configured from the SMBus using the
Receive Enable command. This default method is set by the EEPROM in the pass-through init field.
The following events cause 82598EB to send a notification event to the BMC:
• Receiving a LAN packet that is designated to the BMC.
434