ADM7008
Function Description
100Base-TX application. Alternatively, the receive data stream may be generated by an
external optical receiver as in a 100Base-FX application.
The receiver block consists of the following functional sub-blocks :
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A/D Converter
Adaptive Equalizer and Timing Recovery Module
NRZI/NRZ and Serial/Parallel Decoder
Descrambler
Symbol Alignment Block
Symbol Decoder
Collision Detect Block
Carrier Sense Block
Stream Decoder Block
A/D Converter
High performance A/D converter with 125M sampling rate converts signals received on
RXP/RXN pins to 6 bits data streams; besides it possess auto-gain-control capability that
will further improve receive performance especially under long cable or harsh
detrimental signal integrity. Due to high pass characteristic on transformer, built in base-
line-wander correcting circuit will cancel it out and restore its DC level.
SDP
RXP
RXN
RXP
RXD
4B/5B
DECODER
RXD[3:0]
RXN
BP_DSCR
TESTM
D
SYNC
CRS
RXSTATE
MACHINE
RXDV
100BASE-X RECEIVER
RXER
COL
TXCLK
TXSTATE
MACHINE
TXEN
TXER
TXD[3:0
TXP
TXN
10/100
TX
DRIVER
MLT-3
STATE
MACHINE
SYNC
]
BP_SCR
TXP
TXN
FIBER
OPTIC
DRIVER
TXD
100BASE-X TRANSMITTER
Figure 3-2 100Base-X Block Diagram and Data Path
Adaptive Equalizer and timing Recovery Module
All digital design is especial immune from noise environments and achieves better
ADMtek Inc.
3-3
ETC [ ETC ]
