CS8904
Advanced Product Databook
FEATURES
s
Single-Chip Quad IEEE 802.3-compliant Ethernet
Interface
s
3 V and 5 V Operation
s
Full and Half Duplex Operation
s
Auto-Negotiation with Manual Override Capability
s
Four 10BASE-T Ports with Integrated Active Ana-
log Filters
s
Automatic Polarity Detection and Correction
s
Integrated Manchester Encoder/Decoders
(ENDEC)
s
Link Status LED Driver for Each Port
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Per Port Control - Manual Duplex select (Half or
Full), Auto-Negotiation select, Loopback select
s
Per Port Status - Collision detect, Carrier detect,
Jabber indication, Link status, Duplex status,
Auto-Negotiation status
ORDERING INFORMATION
CS8904-CM5 0 to 70 °C
CS8904-CM3 0 to 70 °C
CDK8904-5
Crystal LAN™ Quad
Ethernet Transceiver
DESCRIPTION
The CS8904 combines four 10BASE-T Ethernet EN-
DECs and transceivers into a single low-cost device.
Complete on-chip 10BASE-T Transceivers and filters
eliminate external components, saving valuable board
space and reducing cost. The CS8904 offers maximum
design flexibility by providing individual control and sta-
tus lines for each of the four interface ports.
The CS8904 supports full-duplex operation, allowing si-
multaneous transmission and reception on all ports.
Auto-negotiation allows the automatic selection of ei-
ther half or full duplex operation on a per-port basis.
The CS8904 is ideally suited for cost-sensitive Ethernet
switch designs. With the CS8904, engineers can design
a four-port Ethernet Transceiver circuit that occupies
less than 1.0 square inch (6.5 sq. cm) of space, exclu-
sive of transformers and RJ-45 connectors.
100-pin MQFP, 5.0 V
100-pin MQFP, 3.3 V
Developer’s Kit, 5.0 V
CS8904 Quad Ethernet Transceiver
STATUS (5)
TxDATA
RxDATA
RxCLK
CONTROL(4)
STATUS (5)
TxDATA
RxDATA
RxCLK
CONTROL(4)
STATUS (5)
TxDATA
RxDATA
RxCLK
CONTROL(4)
STATUS (5)
TxDATA
RxDATA
RxCLK
CONTROL(4)
TxCLK
10BASE-T RX Filters & Receiver
Encoder/Decoder & PLL
10BASE-T TX Filters &Transmitter
LINK LED
RJ-45 10BASE-T
LINK LED
Encoder/Decoder & PLL
10BASE-T RX Filters & Receiver
10BASE-T TX Filters &Transmitter
RJ-45 10BASE-T
LINK LED
Encoder/Decoder & PLL
10BASE-T RX Filters & Receiver
10BASE-T TX Filters &Transmitter
RJ-45 10BASE-T
LINK LED
Encoder/Decoder & PLL
10BASE-T RX Filters & Receiver
10BASE-T TX Filters &Transmitter
RJ-45 10BASE-T
Clock
VDD(11) GND(13)
MODE(3)
RESET
RES
20 MHz XTAL
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
FEB ‘98
Copyright
©
Cirrus Logic, Inc. 1998
(All Rights Reserved)
DS191PP2
CS8904
Crystal LAN™ Quad Ethernet Transceiver
TABLE OF CONTENTS
1.0 INTRODUCTION.....................................................................................................3
1.1 General Description ......................................................................................................... 3
1.2 System Applications ........................................................................................................ 4
1.3 Key Features and Benefits ............................................................................................... 4
1.3.1 Low Cost, Low Noise, More Features .................................................................... 4
2.0 PIN DESCRIPTION.................................................................................................7
2.1 Controller Interface .......................................................................................................... 8
2.2 10BASE-T Interface ........................................................................................................ 9
2.3 LED Pins .......................................................................................................................... 9
2.4 General Pins ..................................................................................................................... 9
3.0 THEORY OF OPERATION ................................................................................. 12
3.1 Overview........................................................................................................................ 12
3.2 Encoder/Decoder (ENDEC)........................................................................................... 12
3.2.1 Encoder ................................................................................................................ 13
3.2.2 Carrier Detection................................................................................................... 13
3.2.3 Clock and Data Recovery ..................................................................................... 13
3.3 10BASE-T Transceiver.................................................................................................. 13
3.3.1 10BASE-T Filters ................................................................................................. 14
3.3.2 Transmitter ............................................................................................................ 14
3.3.3 Receiver ................................................................................................................ 14
3.3.4 Collision Detection ............................................................................................... 15
4.0 FUNCTIONAL DESCRIPTION........................................................................... 16
4.1 Reset and Calibration ..................................................................................................... 16
4.1.1 Reset Operation..................................................................................................... 16
4.1.2 Allowing Time for Reset....................................................................................... 16
4.2 Mode Control ................................................................................................................. 16
4.3 Controller Interface ........................................................................................................ 16
4.3.1 Transmit and Receive Interface ............................................................................ 16
4.3.2 Control and Status Information............................................................................. 17
4.4 External Clock Oscillator............................................................................................... 19
5.0 SPECIFICATIONS................................................................................................. 20
ABSOLUTE MAXIMUM RATINGS................................................................................. 20
RECOMMENDED OPERATING CONDITIONS ............................................................. 20
DC CHARACTERISTICS................................................................................................... 20
DIGITAL INPUT/OUTPUT CHARACTERISTICS .......................................................... 21
SWITCHING CHARACTERISTICS - MODE 1................................................................ 22
SWITCHING CHARACTERISTICS - MODE 2................................................................ 24
SWITCHING CHARACTERISTICS - MODE 3................................................................ 26
SWITCHING CHARACTERISTICS - MODE 4................................................................ 28
SWITCHING CHARACTERISTICS - MODE 5................................................................ 30
10BASE-T CHARACTERISTICS ...................................................................................... 32
CRYSTAL OSCILLATOR REQUIREMENTS.................................................................. 32
6.0 PACKAGE DIMENSIONS.................................................................................... 33
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
2
DS191PP2
CS8904
Crystal LAN™ Quad Ethernet Transceiver
1.0 INTRODUCTION
1.1 General Description
The CS8904 is a true single-chip quad Ethernet
interface solution, incorporating all analog and
digital circuitry needed for a complete Ethernet
front end circuit. It includes high-performance on-
chip filtering, eliminating the need for external
filters. In addition, the CS8904 supports the latest
IEEE Ethernet features including full duplex and
Auto-Negotiation.
The CS8904 incorporates four independent
Manchester encoder/decoders (ENDEC), clock
recovery circuits, 10BASE-T transceivers, and link
status LED circuits. The 10BASE-T transceivers
include drivers, receivers, and high-performance
on-chip analog filters, allowing direct connections
to low-cost isolation transformers. The CS8904’s
superior EMI characteristics are a result of the
high-quality receive and transmit filters which
eliminate the need for external filter packs and help
to make FCC Part 15, Class B compliance easier to
achieve. Each of the four transceivers support half
and full duplex operation and include IEEE-
compliant Auto-Negotiation capability.
20 MHz
XTAL
CS8904
RJ-45
10BASE-T
LINKLED
S
W
I
T
C
H
I
N
G
B
U
S
RJ-45
10BASE-T
SYSTEM
ASIC
LINKLED
RJ-45
10BASE-T
LINKLED
RJ-45
10BASE-T
LINKLED
Figure 1. Ethernet Switching Hub Application of CS8904
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
DS191PP2
3
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
•
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.
•
•
•
•
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
4
DS191PP2
CS8904
Crystal LAN™ Quad Ethernet Transceiver
Port A
Port B
Figure 2. Typical Connection Diagram
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
DS191PP2
5
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