CS8904
Crystal LAN™ Quad Ethernet Transceiver
Each of the CS8904 interface ports support 100,
120, and
150 Ω
shielded and unshielded cables, and
automatic receive reverse-polarity detection and
correction.
1.2 System Applications
The CS8904 is designed for use in Ethernet switch,
hub, and router systems and in ATM switches with
Ethernet support. Offering the latest features of the
IEEE 802.3 specification (ISO/IEC 8802-3:1996),
the CS8904 can be easily interfaced to custom
digital system ASICs. Inputs to the CS8904 from
the digital system ASIC are: transmit data, transmit
enable, duplex selection, auto-negotiation
selection, and loopback selection (loopback from
digital system ASIC through CS8904 to digital
system ASIC), and mode selection. Mode selection
allows the CS8904 to operate with a variety of
compatible Ethernet controllers.
Outputs of the CS8904 to the digital system ASIC
are: transmit clock, receive clock, receive data, and
five status lines: collision detect, carrier detect,
jabber indication, duplex (half / full), and auto-
negotiation (active / inactive).
The Link Status LED indicates that there is an
operational link with the remote network device.
1.3 Key Features and Benefits
1.3.1 Low Cost, Low Noise, More Features
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High-performance on-chip 10BASE-T filters
allow designers to use simple isolation trans-
formers instead of more costly filter/transform-
er packages.
The CS8904 is designed to be used on a 4-layer
circuit board instead of a more expensive multi-
layer board, saving board manufacturing costs.
The CS8904 has been designed for very low
noise emission. As a result FCC testing and
qualification time is reduced considerably.
Half and full duplex operation make the
CS8904 ideal for use in 10BASE-T Ethernet
switch designs and in ATM switch systems that
require 10BASE-T Ethernet ports.
Auto-Negotiation capability that is fully com-
pliant with the latest IEEE Ethernet specifica-
tion (ISO/IEC 8802-3:1995(u)) provides the
newest Ethernet features to system designers.
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