Exar
Corporation 48720 Kato Road, Fremont CA, 94538
(510) 668-7000
FAX (510) 668-7017
www.exar.com
á
XRT4500
MULTIPROTOCOL SERIAL NETWORK INTERFACE IC
SEPTEMBER 2002
REV. 1.0.7
GENERAL DESCRIPTION
The XRT4500 is a fully integrated multiprotocol serial
interface. It supports all of the popular serial commu-
nication interface standards such as ITU-T V.35, ITU-
T V.36, EIA530A, RS232 (ITU-T V.28), ITU-T X.21
and RS449. It can easily be interfaced with most
common types of Serial Communications Controllers
(SCCs). This device contains eight receivers and
eight transmitters, in groups of six or seven. It is a
complete solution containing all of the required
source and load termination resistors
in one 80-pin
TQFP package. The XRT4500 operates at higher
speeds (20MHz for V.35 and 256kbps for V.28).
The XRT4500 can be configured to operate in one of
the seven interface standards in either DTE, or DCE
modes of operation and power down mode. It fully
supports echoed clock as well as clock and data in-
version. Loopbacks are supported in DTE and DCE
modes of operation. This feature eliminates the need
for external circuitry for loopback implementation.
Control signals such as RI, RL, DCD, DTR, DSR are
protected against glitches by internal filters. These fil-
ters can be turned off. The XRT4500 provides an in-
ternal oscillator (clock signal) which can be used to
conduct standalone diagnostics of DTE equipment.
B
LOCK
D
IAGRAM
FEATURES
Pin Programmable Multiprotocol Serial Interface
V.35, V.36, EIA-530 A, RS232 (V.28), V.10, V.11, X.21
and RS449 Communication Interface Standards
V.28, V.10, V.11 and V.35 Electrical Interfaces are
‘CTR2’ Compliant
Contains On-Chip Source and Load Termination
Resistors
Contains Eight Receivers and Eight Transmitters
with Switchable DTE and DCE Modes
Glitch Filters on the Control Signals (Selectable)
+5V Single Power Supply with internal DC-DC
Converter
Full Support of Loopbacks, Data & Clock Inversion,
and Echoed Clock in DTE and DCE Modes
Full Support of Most Popular Types of HDLC Control-
lers (Single, Double, and Triple Clocks supported)
High-speed V.28 Driver: 256KHz
Internal Oscillator for Standalone DTE Loopback
Testing
Control Signals Can Be Registered and Non-regis-
tered
Control Signals Can Be Tri-stated for Bus-based
Designs
“Cable Safe” Operation Supported
ESD Protection Over ± 1KV Range
TTL Level Digital Inputs
TTL/CMOS Digital Outputs
APPLICATIONS
Data Service Units (DSU)
Channel Service Units (CSU)
Routers
Bridges
Access Equipment
TX2
TX1
RX3
RX2
RX1
TX4
TX3
RX4
RX5
TX5
TX6
RX6
TX7
RX8
RX7
V.10, V.11, V.35, V.28
Electrical Interfaces
Signals
TXD, RXD
High Speed Data
and Clock
V.10, V.11, V.35, V.28
V.10, V.11, V.35, V.28
SCTE Signals:
DCE Transmitter,
DTE Receiver
RTS, CTS
DTR, DSR
LL, RL, RI (TM)
LL, RL, RI (TM)
Mode and Configuration
Control
Switching Regulator
DC-DC Converter
V.10, V.11, ---- , V.28
V.10, V.11, ---- , V.28
V.10, V.11, ---- , V.28
V.10, ---- , ---- , V.28
V.10, ---- , ---- , V.28
High Speed Transceiver
TXC, RXC
High Speed Data
and Clock
DCD Signals:
DCE Transmitter,
DTE Receiver
Diagnostic Transceivers
TX8
Handshaking/Control Transceivers