ICS1893CFT 参数 Datasheet PDF下载

ICS1893CF Data Sheet - Release

Chapter 3 Overview of the ICS1893CF

3.1 100Base-TX Operation

During 100Base-TX data transmission, the ICS1893CF accepts packets from a MAC and inserts

Start-of-Stream Delimiters (SSDs) and End-of-Stream Delimiters (ESDs) into the data stream. The

ICS1893CF encapsulates each MAC frame, including the preamble, with an SSD and an ESD. As per the

ISO/IEC Standard, the ICS1893CF replaces the first octet of each MAC preamble with an SSD and

appends an ESD to the end of each MAC frame.

When receiving data from the medium, the ICS1893CF removes each SSD and replaces it with the

pre-defined preamble pattern before presenting the nibbles to its MAC Interface. When the ICS1893CF

encounters an ESD in the received data stream, signifying the end of the frame, it ends the presentation of

nibbles to its MAC Interface. Therefore, the local MAC receives an unaltered copy of the transmitted frame

sent by the remote MAC.

During periods when MAC frames are being neither transmitted nor received, the ICS1893CF signals and

detects the IDLE condition on the Link Segment. In the 100Base-TX mode, the ICS1893CF transmit

channel sends a continuous stream of scrambled ones to signify the IDLE condition. Similarly, the

ICS1893CF receive channel continually monitors its data stream and looks for a pattern of scrambled ones.

The results of this signaling and monitoring provide the ICS1893CF with the means to establish the

integrity of the Link Segment between itself and its remote link partner and inform its Station Management

Entity (STA) of the link status.

For 100M data transmission, the ICS1893CF MAC Interface is configured to provide a 100M Media

Independent Interface (MII).

3.2 10Base-T Operation

During 10Base-T data transmission, the ICS1893CF inserts only the IDL delimiter into the data stream. The

ICS1893CF appends the IDL delimiter to the end of each MAC frame. However, since the 10Base-T

preamble already has a Start-of-Frame delimiter (SFD), it is not required that the ICS1893CF insert an

SSD-like delimiter.

When receiving data from the medium (such as a twisted-pair cable), the ICS1893CF uses the preamble to

synchronize its receive clock. When the ICS1893CF receive clock establishes lock, it presents the

preamble nibbles to its MAC Interface. The 10M MAC Interface uses the standard MII Interface.

In 10M operations, during periods when MAC frames are being neither transmitted nor received, the

ICS1893CF signals and detects Normal Link Pulses. This action allows the integrity of the Link Segment

with the remote link partner to be established and then reported to the ICS1893CF’s STA.

ICS1893CF, Rev. F, 03/01/07

Copyright © 2007, Integrated Device Technology, Inc.

All rights reserved.

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Mar. 2007