3X38FTR Datasheet, PDF (37/64 Pages) Agere Systems – OCTAL-FET (Fast Ethernet Transceiver) for 10Base-T/100Base-TX/FX

Preliminary Data Sheet
September 2000
3X38FTR 208-Pin SQFP
OCTAL-FET for 10Base-T/100Base-TX/FX
Functional Description (continued)
10Base-T Module
The 10Base-T Transceiver Module is IEEE 802.3 com-
pliant. It includes the receiver, transmitter, collision,
heartbeat, loopback, jabber, waveshaper, and link
integrity functions, as defined in the standard. Figure 13
provides an overview for the 10Base-T module.
The 3X38 10Base-T module is comprised of the follow-
ing functional blocks:
s Manchester encoder and decoder
s Collision detector
s Link test function
s Transmit driver and receiver
s Serial and parallel interface
s Jabber and SQE test functions
s Polarity detection and correction
TPIN±
RECEIVE
FILTER
SMART
SQUELCH
CLOCK
RECOVERY
RXCLK
10BASE-T
RECEIVE
PCS
CRS
RXD[3:0]
RXDV
COL
MII-TO-RMII
CONVERTER
RCRS_DV
RRXD[1:0]
TPOUT±
10/100
TX DRIVER
WAVE
SHAPER
10BASE-T
TRANSMIT
PCS
TXEN
TXER
TXD[3:0]
TXCLK
MII-TO-RMII
CONVERTER
Figure 13. 10Base-T Module Data Path
RTXEN
RTXD[1:0]
RTXCLK
5-7521(F).b
Operation Modes
The 3X38 10Base-T module is capable of operating in either half-duplex mode or full-duplex mode. In half-duplex
mode, the 3X38 functions as an IEEE 802.3 compliant transceiver with fully integrated filtering. The COL signal is
asserted during collisions or jabber events, and the CRS signal is asserted during transmit and receive. In full-
duplex mode, the 3X38 can simultaneously transmit and receive data.
Manchester Encoder/Decoder: Data encoding and transmission begins when the transmit enable input (TXEN)
goes high and continues as long as the transceiver is in good link state. Transmission ends when the transmit
enable input goes low. The last transition occurs at the center of the bit cell if the last bit is a 1, or at the boundary
of the bit cell if the last bit is 0.
Decoding is accomplished by a differential input receiver circuit and a phase-locked loop that separates the
Manchester-encoded data stream into clock signals and NRZ data. The decoder detects the end of a frame when
no more midbit transitions are detected. Within one and a half bit times after the last bit, carrier sense is deas-
serted.
Lucent Technologies Inc.
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