82576EB Datasheet, PDF (16/34 Pages) Intel Corporation – LAN Access Division

Specification Changes - Intel^® 82576EB GbE Controller
Implication: Loss of link can cause a loss of the MNG session. These events do not normally occur
during a reboot cycle, so it is expected that no effect will be seen in most circumstances.
Workaround: N/A.
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7. SerDes: AN_TIMEOUT Only Works When Link Partner Idle
Clarification: The auto-negotiation timeout mechanism (PCS_LCTL.AN_TIMEOUT_EN) only works if the
SerDes partner is sending idle code groups continuously for the duration of the timeout
period, which is the usual case. However, if the partner is transmitting packets, an auto-
negotiation timeout will not occur since auto-negotiation is restarted at the beginning of
each packet.
If the partner has an application that indefinitely transmits data despite the lack of any
response, it is possible that a link will not be established. If this is a concern, the auto-
negotiation timeout mechanism may be considered unreliable and an additional software
mechanism could be used to disable auto-negotiation if sync is maintained without a link
being established (PCS_LSTS.SYNC_OK=1b and PCS_LSTS.LINK_OK=0b) for an
extended period of time.
Note:
To Disable Auto-Negotiation when using an Intel driver, use the SerDes Forced Mode
Override bit as described in Specification Change #5.
Workaround: N/A
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8. Padding on Transmitted SCTP Packets
Clarification: When using the 82576 to offload the CRC calculation for transmitted SCTP packets,
software should not add Ethernet padding bytes to short packets (less than 64 bytes).
Instead, the TCTL.PSP bit should be set so that the 82576 pads the packets after
performing the CRC calculation.
Workaround: N/A
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9. Dynamic LED Modes Can Only Be Used in an Active Low Configuration
Clarification: In any of the dynamic LED modes (FILTER_ACTIVITY, LINK/ACTIVITY, COLLISION,
ACTIVITY, PAUSED), LED blinking should only be enabled if the LED signal is configured
as an active low output.
Workaround: N/A
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1.5.3 Specification Changes
1. Update to PBA Number EEPROM Word Format
Change:
PBA Number Module — Word 0x8-0x9
The nine-digit Printed Board Assembly (PBA) number used for Intel manufactured
Network Interface Cards (NICs) is stored in EEPROM.
Intel^® 82576EB GbE Controller
Specification Update
16
Revision: 2.85
September 2012