ICS1893AFILFT datasheet(66/137 Pages) RENESAS

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ICS1893AF, Rev D 10/26/04

October, 2004

Chapter 8

Management Register Set

ICS1893AF Data Sheet - Release

8.3.9

Remote Fault (bit 1.4)

An STA reads bit 1.4 to determine if a Remote Fault exists. The ICS1893AF sets bit 1.4 based on the

Remote Fault bit received from its remote link partner. The ICS1893AF receives the Remote Fault bit as

part of the Link Code Word exchanged during the auto-negotiation process. If the ICS1893AF receives a

Link Code Word from its remote link partner and the Remote Fault bit is set to:

• Zero, then the ICS1893AF sets bit 1.4 to logic zero.

• One, then the ICS1893AF sets bit 1.4 to logic one. In this case, the remote link partner is reporting the

detection of a fault, which typically occurs when the remote link partner is having a problem with its

receive channel.

Bit 1.4 is a latching high status bit. (For more information on latching high and latching low bits, see Section

8.1.4.1, “Latching High Bits” and Section 8.1.4.2, “Latching Low Bits”.)

Note:

The ICS1893AF has two versions of the Remote Fault bit.

• One version of the Remote Fault bit is a latching high version. An STA can access this version

through either Management Register 1 (bit 1.4) or 17 (bit 17.1). This bit 1.4/17.1 is cleared when

an STA reads either of these registers. (Bit 1.4 is identical to bit 17.1 in that they are the same

internal bit.)

• Another version of the Remote Fault bit is updated whenever the ICS1893AF receives a new

Link Control Word. An STA can access this version through Management Register 5 (bit 5.13),

which like bits 1.4/17.1, also reports the status of the Remote Fault bit received from the remote

link partner. However, bit 5.13 is not a latching high bit.

The operation of both bit 1.4/17.1 and bit 5.13 are in compliance with the IEEE Std 802.3u.

8.3.10

Auto-Negotiation Ability (bit 1.3)

The STA reads bit 1.3 to determine if the ICS1893AF can support the auto-negotiation process. If the

ICS1893AF:

• Cannot support the auto-negotiation process, it clears bit 1.3 to logic zero.

• Can support the auto-negotiation process, it sets bit 1.3 to logic one. (For the ICS1893AF, the default

value of bit 1.3 is logic one.)

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