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XR17L152
3.3V PCI BUS DUAL UART
AUGUST 2003
REV. 1.1.0
FEATURES
GENERAL DESCRIPTION
The XR17L1521 (L152) is a monolithic dual PCI Bus
Universal Asynchronous Receiver and Transmitter (UART)
in Exar’s PCI Bus UART family. The device is designed to
meet today’s 32-bit PCI Bus and high bandwidth
requirements in communication systems. The global
interrupt source register provides a complete interrupt
status indication for both channels to speed up interrupt
parsing. Each UART is independently controlled and has its
own 16C550 compatible 5G (Fifth Generation) register set,
transmit and receive FIFOs of 64 bytes, fully programmable
transmit and receive FIFO trigger levels, transmit and
receive FIFO level counters, automatic hardware flow
control with programmable hysteresis, automatic software
(Xon/Xoff) flow control, automatic half-duplex control
output, wireless IrDA (Infrared Data Association) infrared
encoder/decoder, 8 multi-purpose definable inputs/outputs,
and a 16-bit general purpose timer/counter.
• High Performance DUART
• PCI Bus 2.2 Target Interface Compliance
• 3.3 V PCI Bus Compliant up to 33 MHz Clock
• 5 Volt Tolerant Serial Inputs
• 32-bit PCI Bus Interface with EEPROM Interface
• A Global Interrupt Source Register for both UARTs
• Data Transfer in Byte, Word and Double-word
• Data Read/Write Burst Operation
• Each UART is independently controlled with:
•16C550 Compatible 5G Register Set
•64-byte Transmit and Receive FIFOs
•Transmit and Receive FIFO Level Counters
•Programmable TX and RX FIFO Trigger Level
•Automatic RTS/CTS or DTR/DSR Flow Control
•Automatic Xon/Xoff Software Flow Control
NOTE: 1 Covered by U.S. Patents #5,649,122, #5,949,787
APPLICATIONS
• Network Management
•Automatic RS485 Half-duplex Control Output with
Selectable Turn-around Delay (0 to 15 bit-times)
• Factory Automation and Process Control
• Ethernet Network to Serial Ports
• Point-of-Sale Systems
•Infrared (IrDA 1.0) Data Encoder/Decoder
•Programmable Data Rate with Prescaler
•Up to 3.125 Mbps Data Rate at 8X Sampling
• Eight Multi-Purpose Inputs/outputs
• Multi serial ports RS-232/RS-422/RS-485 Cards
• A General Purpose 16-bit Timer/Counter
• Sleep Mode with Automatic Wake-up Indicator
• Same package and pin-out as XR17C152 and
XR17D152 (14x14x1.0 mm TQFP)
FIGURE 1. BLOCK DIAGRAM
3.3V VCC
GND
*5V Tolerance for non-PCI Inputs
UART Channel 0
CLK
RST#
AD[31:0]
C/BE[3:0]#
FRAME#
IRDY#
64 Byte TX FIFO
UART
TX0, RX0, DTR0#,
DSR0#, RTS0#,
CTS0#, CD0#, RI0#
Regs
IR
ENDEC
TX
& RX
PCI Local
Bus
Interface
TRDY#
BRG
64 Byte RX FIFO
Device
Configuration
Registers
DEVSEL#
STOP#
INTA#
UART Channel 1
TX1, RX1, DTR1#,
IDSEL
PERR#
SERR#
PAR
64 Byte TX FIFO
UART
Regs
DSR1#, RTS1#,
CTS1#, CD1#, RI1#
IR
ENDEC
TX
& RX
BRG
64 Byte RX FIFO
Configuration
Space
Registers
16-bit
Timer/Counter
Multi-purpose
.
EECK
EEDI
MPIO0- MPIO7
EEPROM
Interface
Inputs/Outputs
EEDO
EECS
XTAL1
XTAL2
Crystal Osc/Buffer
ENIR
EN485#
TMRCK
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com