ICS1893AF Data Sheet - Release
Chapter 7 Functional Blocks
7.3 Functional Block: 100Base-X PCS and PMA Sublayers
The ICS1893AF is fully compliant with clause 24 of the ISO/IEC specification, which defines the 100Base-X
Physical Coding sublayer (PCS) and Physical Medium Attachment (PMA) sublayers.
7.3.1 PCS Sublayer
The ICS1893AF 100Base-X PCS sublayer provides two interfaces: one to a MAC/repeater and the other to
the ICS1893AF PMA sublayer. An ICS1893’s PCS sublayer performs the transmit, receive, and control
functions and consists of the following:
• PCS Transmit sublayer, which provides the following:
– Parallel-to-serial conversion
– 4B/5B encoding
– Collision detection
• PCS Receive sublayer, which provides the following:
– Serial-to-parallel conversion
– 4B/5B encoding
– Carrier detection
– Code group framing
• PCS control functions, which provide:
– Assertion of the CRS (carrier sense) signal
– Assertion of the COL (collision detection) signal
7.3.2 PMA Sublayer
The ICS1893AF 100Base-X PMA Sublayer consists of two interfaces: one to the Physical Coding sublayer
and the other to the Physical Medium Dependent sublayer. Functionally, the PMA sublayer is responsible
for the following:
• Link Monitoring
• Carrier Detection
• NRZI encoding/decoding
• Transmit Clock Synthesis
• Receive Clock Recovery
ICS1893AF, Rev D 10/26/04
October, 2004
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
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