1893Y-10 IDT, Integrated Device Technology Inc, 1893Y-10 Datasheet - Page 18

• Manufacturer Part Number: 1893Y-10
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of 1893Y-10

• Lead Free Status / RoHS Status: Not Compliant

4.1 100Base-TX Operation
4.2 10Base-T Operation
ICS1893 Rev C 6/6/00
During 100Base-TX data transmission, the ICS1893 accepts packets from a MAC/repeater and inserts
Start-of-Stream Delimiters (SSDs) and End-of-Stream Delimiters (ESDs) into the data stream. The
ICS1893 encapsulates each MAC/repeater frame, including the preamble, with an SSD and an ESD. As
per the ISO/IEC Standard, the ICS1893 replaces the first octet of each MAC preamble with an SSD and
appends an ESD to the end of each MAC/repeater frame.
When receiving data from the medium, the ICS1893 removes each SSD and replaces it with the
pre-defined preamble pattern before presenting the nibbles to its MAC/Repeater Interface. When the
ICS1893 encounters an ESD in the received data stream, signifying the end of the frame, it ends the
presentation of nibbles to its MAC/Repeater Interface. Therefore, the local MAC/repeater receives an
unaltered copy of the transmitted frame sent by the remote MAC/repeater.
During periods when MAC frames are being neither transmitted nor received, the ICS1893 signals and
detects the IDLE condition on the Link Segment. In the 100Base-TX mode, the ICS1893 transmit channel
sends a continuous stream of scrambled ones to signify the IDLE condition. Similarly, the ICS1893 receive
channel continually monitors its data stream and looks for a pattern of scrambled ones. The results of this
signaling and monitoring provide the ICS1893 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 ICS1893 MAC/Repeater Interface can be configured to provide either a
100M Media Independent Interface (MII) or a 100M Symbol Interface. With the Symbol Interface
configuration, the data stream bypasses the ICS1893 Physical Coding sublayer (PCS). In addition:
1. The ICS1893 shifts the responsibility of performing the 4B/5B translation to the MAC/repeater. As a
2. The latency through the ICS1893 is reduced. (The ICS1893 provides this 100M Symbol Interface
During 10Base-T data transmission, the ICS1893 inserts only the IDL delimiter into the data stream. The
ICS1893 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 ICS1893 insert an SSD-like
delimiter.
When receiving data from the medium (such as a twisted-pair cable), the ICS1893 uses the preamble to
synchronize its receive clock. When the ICS1893 receive clock establishes lock, it presents the preamble
nibbles to its MAC/Repeater Interface. The 10M MAC/Repeater Interface can be configured as either a
10M MII, a 10M Serial Interface, or a Link Pulse Interface.
In 10M operations, during periods when MAC frames are being neither transmitted nor received, the
ICS1893 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 ICS1893’ s STA.
result, the requirement is for a 5-bit data path between the MAC/repeater and the ICS1893.
primarily for repeater applications for which latency is a critical performance parameter.)
ICS1893 Data Sheet - Release
Copyright © 2000, Integrated Circuit Systems, Inc.
All rights reserved.
18
Chapter 4 Overview of the ICS1893
June, 2000