IDT1893CFLFT IDT, Integrated Device Technology Inc, IDT1893CFLFT Datasheet - Page 52

• Manufacturer Part Number: IDT1893CFLFT
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT1893CFLFT

• Lead Free Status / RoHS Status: Compliant

7.3.6 IEEE Reserved Bits (bits 1.10:7)
7.3.7 MF Preamble Suppression (bit 1.6)
7.3.8 Auto-Negotiation Complete (bit 1.5)
ICS1893CF, Rev. J, 08/11/09
The IEEE reserves these bits for future use. When an STA:
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•
Both the ISO/IEC standard and the ICS1893CF reserve the use of some Management Register bits. ICS
uses some reserved bits to invoke ICS1893CF test functions. To ensure proper operation of the
ICS1893CF, an STA must maintain the default value of these bits. Therefore, ICS recommends that an STA
write the default value to all reserved bits during all Management Register write operations.
Reserved bits 1.10:7 are Command Override Write (CW) bits. When bit 16.15, the Command Register
Override bit, is logic:
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Status Register bit 1.6 is the Management Frame (MF) Preamble Suppression bit. The ICS1893CF sets bit
1.6 to inform the STA of its ability to receive frames that do not have a preamble. When this bit is logic:
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Although the ICS1893CF supports Management Frame Preamble Suppression, its default value for bit 1.6
is logic zero. This default value ensures that bit 1.6 is backward compatible with the ICS1890, which does
not have this capability. As the means of enabling this feature, the ICS1893CF implements bit 1.6 as a
Command Override Write bit, instead of as a Read-Only bit as in the ICS1890. An STA uses the bit 1.6 to
enable MF Preamble Suppression in the ICS1893CF. [See the description of bit 16.15, the Command
Override Write Enable bit, in
An STA reads bit 1.5 to determine the state of the ICS1893CF auto-negotiation process. The ICS1893CF
sets the value of this bit using two criteria. When its Auto-Negotiation sublayer is:
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Bit 1.5 is a latching high (LH) bit. (For more information on latching high and latching low bits, see
7.1.4.1, “Latching High Bits”
Note:
Reads a reserved bit, the ICS1893CF returns a logic zero.
Writes a reserved bit, the STA must use the default value specified in this data sheet.
Zero, the ICS1893CF prevents all STA writes to CW bits.
One, an STA can modify the value of these bits.
Zero, the ICS1893CF is indicating it cannot accept frames with a suppressed preamble.
One, the ICS1893CF is indicating it can accept frames that do not have a preamble.
Disabled, the ICS1893CF sets bit 1.5 to logic zero.
Enabled, the ICS1893CF sets bit 1.5 to a value based on the state of the Auto-Negotiation State
Machine. In this case, it sets bit 1.5 to logic one only upon completion of the auto-negotiation process.
This setting indicates to the STA that a link is arbitrated and the contents of Management Registers 4, 5,
and 6 are valid. For details on the auto-negotiation process, see
Auto-Negotiation”.
An Auto-Negotiation Restart does not clear an LH bit. However, performing two consecutive reads
of this register provides the present state of the bit.
ICS1893CF Data Sheet - Release
Copyright © 2009, Integrated Device Technology, Inc.
and
Section 7.11, “Register 16: Extended Control
Section 7.1.4.2, “Latching Low
All rights reserved.
52
Bits”.)
Section 6.2, “Functional Block:
Chapter 7 Management Register Set
Register”.]
August, 2009
Section