ICS1893Y-10 Datasheet, PDF (78/150 Pages) –

ICS1893Y-10 Data Sheet - Release
Chapter 7 Management Register Set
7.6.1 Next Page (bit 4.15)
This bit indicates whether the ICS1893Y-10 uses the Next Page Mode functions during the auto-negotiation
process. If bit 4.15 is logic:
• Zero, then the ICS1893Y-10 indicates to its remote link partner that these features are disabled.
(Although the default value of this bit is logic zero, the ICS1893Y-10 does support the Next Page
function.)
• One, then the ICS1893Y-10 advertises to its remote link partner that this feature is enabled.
7.6.2 IEEE Reserved Bit (bit 4.14)
The ISO/IEC specification reserves this bit for future use. However, the ISO/IEC Standard also defines bit
4.14 as the Acknowledge bit.
When this reserved bit is read by an STA, the ICS1893Y-10 returns a logic zero. However, whenever an
STA writes to this reserved bit, it must use the default value specified in this data sheet. ICS uses some
reserved bits to invoke auxiliary functions. To ensure proper operation of the ICS1893Y-10, an STA must
maintain the default value of these bits. Therefore, ICS recommends that an STA always write the default
value of any reserved bits during all management register write operations.
Reserved bit 4.14 is a Command Override Write (CW) bit. Whenever bit 16.15 (the Command Register
Override bit) is logic:
• Zero, the ICS1893Y-10 isolates all STA writes to bit 4.14.
• One, an STA can modify the value of bit 4.14.
7.6.3 Remote Fault (bit 4.13)
When the ICS1893Y-10 Auto-Negotiation sublayer is enabled, the ICS1893Y-10 transmits the Remote
Fault bit 4.13 to its remote link partner during the auto-negotiation process. The Remote Fault bit is part of
the Link Code Word that the ICS1893Y-10 exchanges with its remote link partner. The ICS1893Y-10 sets
this bit to logic one whenever it detects a problem with the link, locally. The data in this register is sent to the
remote link partner to inform it of the potential problem. If the ICS1893Y-10 does not detect a link fault, it
clears bit 4.13 to logic zero.
Whenever the ICS1893Y-10:
• Does not detect a link fault, the ICS1893Y-10 clears bit 4.13 to logic zero.
• Detects a problem with the link, during the auto-negotiation process, this bit is set. As a result, the data
on this bit is sent to the remote link partner to inform it of the potential problem.
7.6.4 IEEE Reserved Bits (bits 4.12:10)
The IEEE reserves these bits for future use. When an STA:
• Reads a reserved bit, the ICS1893Y-10 returns a logic zero.
• Writes to a reserved bit, it must use the default value specified in this data sheet.
The ICS1893Y-10 uses some reserved bits to invoke auxiliary functions. To ensure proper operation of the
ICS1893Y-10, an STA must maintain the default value of these bits. Therefore, ICS recommends that
during any STA write operation, an STA write the default value to all reserved bits, even those bits that are
Read Only.
ICS1893Y-10 Rev F 1/20/04
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
78
January, 2004