ICS1893AG Data Sheet - Preliminary
Chapter 7 Functional Blocks
7.3 Functional Block: 100Base-X PCS and PMA Sublayers
The ICS1893AG 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 ICS1893AG 100Base-X PCS sublayer provides two interfaces: one to a MAC/repeater and the other
to the ICS1893AG 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 ICS1893AG 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
ICS1893AG, Rev. A 04/14/05
Copyright © 2005, Integrated Circuit Systems, Inc.
All rights reserved.
39
April, 2005