Revision: 2.85

September 2012

Specification Update

21

1.5.4

Errata

1. Internal Copper PHY: Improperly Implements Auto-Negotiation Advertisement Register

Problem:

The 82576 incorrectly transmits the link code word due to a write to register 4.

Implication: See the following notes on link code word bits:

Bits 4.7 and 4.8: Are always set in the base page transmission.

Bit 4.9: Represents 100BASE-T4 support. The 82576 does not support T4. It is unlikely

that the auto-negotiation feature of the 82576 will be used in an implementation to

advertise the presence of a T4 physical device. Therefore, the fact that this device does

not allow T4 to be advertised is not significant.

Bit 4.15: The 82576 always supports Next Page (regardless the value of bit 4.15). When

bit 4.15 is set to "one," the 82576 requires Register 7 (AN Next Page Transmit Register)

to be written to complete the Next Page Exchange. In this case, the 82576's Next Pages

do not correspond to Register 7, but contain valid 1000BASE-T Next Pages.

Workaround: Any write to register 4 should be followed with a restart of Auto-Negotiation by setting bit

0.9.

Status:

A1, A2 NoFix

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2. PCIe: Differential Return Loss More than Specified Value

Problem:

The PCIe transmitter's differential return loss is -9.7 dB instead of the -10 dB

requirement.

Implication: The out-of-specification return loss adds noise to the Tx line. Performance is not affected.

Workaround: None.

Status:

A1, A2 NoFix

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3. SGMII Counters Incorrectly Increment on Collision

Problem:

In SGMII mode/half duplex, the statistics counters listed below incorrectly increment

when a collision occurs:

Name

Definition

Location

RLEC

Length error counter

0X4040

CRCERRS

CRC error counter

0x4000

RFC

receive frame counter

0x40A8

Implication: Error counters may not be accurate.

Workaround: None.

Status:

A1, A2 NoFix

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