1893CKLFT IDT, 1893CKLFT Datasheet - Page 59

• Manufacturer Part Number: 1893CKLFT
• Description: Ethernet ICs 3.3V 10/100 BASE TX INTEGRATED PHYCEIVER
• Manufacturer: IDT

Specifications of 1893CKLFT

• Rohs: yes
• Part # Aliases: ICS1893CKLFT

7.6.2 IEEE Reserved Bit (bit 4.14)
7.6.3 Remote Fault (bit 4.13)
7.6.4 IEEE Reserved Bits (bits 4.12:10)
ICS1893CK-40, Rev. C, 06/02/09
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 ICS1893CK-40 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 ICS1893CK-40, 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:
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•
When the ICS1893CK-40 Auto-Negotiation sublayer is enabled, the ICS1893CK-40 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 ICS1893CK-40 exchanges with its remote link partner. The ICS1893CK-40
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 ICS1893CK-40 does not detect a link
fault, it clears bit 4.13 to logic zero.
Whenever the ICS1893CK-40:
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•
The IEEE reserves these bits for future use. When an STA:
•
•
The ICS1893CK-40 uses some reserved bits to invoke auxiliary functions. To ensure proper operation of
the ICS1893CK-40, 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.
Zero, the ICS1893CK-40 isolates all STA writes to bit 4.14.
One, an STA can modify the value of bit 4.14.
Does not detect a link fault, the ICS1893CK-40 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.
Reads a reserved bit, the ICS1893CK-40 returns a logic zero.
Writes to a reserved bit, it must use the default value specified in this data sheet.
ICS1893CK-40 Data Sheet Rev. C - Release
Copyright © 2009, Integrated Device Technology, Inc.
All rights reserved.
59
Chapter 7 Management Register Set
June 2009