82576EB Datasheet, PDF (32/34 Pages) Intel Corporation – LAN Access Division

Errata - Intel^® 82576EB GbE Controller
Status:
A1, A2 NoFix
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40. TSYNC: Auxiliary Timestamp from SDP is Unreliable
Problem:
SDP inputs to the timestamp logic are not properly synchronized. As a result, both the
Auxiliary Timestamp Register values and the Auxiliary Timestamp Taken bits in TSAUXC
are sometimes loaded incorrectly.
Implication: The auxiliary timestamp feature should be considered unreliable.
Workaround: For applications that use the auxiliary timestamp feature to synchronize to an external
clock, it might be acceptable to drop some of the samples. For such applications, software
can filter out many of the incorrect timestamp values by comparing them to an
approximate expected timestamp and discarding unreasonable values.
In addition, the following method can be used to filter out incorrect values:
— Connect the input signal to two SDP inputs for the same port.
— Using the TSSDP register, assign one of the SDP inputs to AUX0 and the other SDP
input to AUX1.
— When reading the TSAUXC register to check for new samples, check that both
AUTT0 and AUTT1 are set. Otherwise, discard the sample.
— Read both the AUX0 and AUX1 timestamp values and compare the values. Discard
the values if they differ by more than the sampling uncertainty -- 8 ns if the SDP
inputs are balanced externally or slightly higher if the external trace lengths differ
significantly.
Using this method, along with a SW filter for expected values, almost all errors can be
filtered out with the remaining samples having a very high probability of being correct.
Status:
A1, A2 NoFix
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41. NC-SI: Get Link Status Command Might Cause Corruption of PHY Registers
Problem:
The firmware code that executes the NC-SI Get Link Status command does not acquire
the PHY semaphore bit when accessing PHY registers. Therefore, there could be
corruption of the PHY registers if the driver accesses PHY registers in parallel with the
firmware.
Implication: Corruption of the PHY registers could result in a link failure and/or a driver failure if NC-SI
Get Link Status command is used.
Workaround: None. See status.
Status:
A1, EEPROM/NVM Fix
Fixed in EEPROM version 2.1 or later.
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42. NC-SI: Get NC-SI Pass-through Statistics Response Format
Problem:
The NC-SI Specification, version 1.0.0a defines the Pass-through Tx Packets counter
contained in the Get NC-SI Pass-through Statistics Response Packet to be an 8-byte field.
The 82576 provides this counter as a 4-byte field.
Intel^® 82576EB GbE Controller
Specification Update
32
Revision: 2.85
September 2012