ICS1893 Datasheet, PDF (70/152 Pages) Integrated Circuit Systems – 3.3-V 10Base-T/100Base-TX Integrated PHYceiver™

ICS1893 Data Sheet - Release
Chapter 8 Management Register Set
8.3.9 Remote Fault (bit 1.4)
An STA reads bit 1.4 to determine if a Remote Fault exists. The ICS1893 sets bit 1.4 based on the Remote
Fault bit received from its remote link partner. The ICS1893 receives the Remote Fault bit as part of the
Link Code Word exchanged during the auto-negotiation process. If the ICS1893 receives a Link Code
Word from its remote link partner and the Remote Fault bit is set to:
• Zero, then the ICS1893 sets bit 1.4 to logic zero.
• One, then the ICS1893 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 ICS1893 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 ICS1893 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 ICS1893 can support the auto-negotiation process. If the
ICS1893:
• 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 ICS1893, the default value
of bit 1.3 is logic one.)
ICS1893 Rev C 6/6/00
Copyright © 2000, Integrated Circuit Systems, Inc.
All rights reserved.
70
June, 2000