Intel 82555 - Manual (Page 8)

82555 — Networking Silicon
4 Datasheet
• Receive: The 82555 takes receive analog MLT-3 data from the receive differential pair and
converts it into a digital 125 Mbps stream, recovering both clock and data signals.
2.2 10 Mbps Mode
The 82555 operation in 10BASE-T mode is similar to the 82555 operation in 100BASE-TX mode.
Manchester encoding and decoding is used instead of 4B/5B encoding/decoding and scrambling/
descrambling. In addition, the Transmit Clock and Receive Clock (MII clock signals) provide 2.5
MHz instead of 25 MHz.
Figure 3. 82555 Analog Logic
4b/5b
Encoding
Scrambler
Serialization
MII TX Interface
NRZ to NRZI
NRZI to MLT3
4b/5b
Decoding
De-scrambler
Serial to 5B
MII RX Interface
NRZI to NRZ
MLT3 to NRZI
Magnetics Module
RJ-45 Connector
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