XR16V794 Datasheet, PDF (1/53 Pages) Exar Corporation – HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL

XR16V794
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL
MAY 2007
REV. 1.0.0
GENERAL DESCRIPTION
The XR16V794¹ (794), is a 2.25V to 3.6V octal
Universal Asynchronous Receiver and Transmitter
(UART) with 5V tolerant serial (modem) inputs. The
highly integrated device is designed for high
bandwidth requirement in communication systems.
The global interrupt source register provides a
complete interrupt status indication for all 4 channels
to speed up interrupt parsing. Each UART has its own
16C550 compatible set of configuration registers, TX
and RX FIFOs of 64 bytes, fully programmable
transmit and receive FIFO trigger levels, TX and RX
FIFO level counters, automatic RTS/CTS or DTR/
DSR hardware flow control with programmable
hysteresis, autoamtic software (Xon/Xoff) flow
control, RS-485 half-duplex direction control with
programmable turn-around delay, Intel or Motorola
bus interface and sleep mode with a wake-up
indicator.
NOTE: Covered by US patents #5,649,122 and #5,949,787
APPLICATIONS
• Remote Access Servers
• Ethernet Network to Serial Ports
• Network Management
• Factory Automation and Process Control
• Point-of-Sale Systems
• Multi-port RS-232/RS-422/RS-485 Cards
FEATURES
• 2.25V to 3.6V with 5V Tolerant Serial Inputs
• Single Interrupt output for all 4 UARTs
• A Global Interrupt Source Register for all 4 UARTs
• 5G “Flat” UART Registers for easier programming
• Simultaneous Initialization of all UART channels
• A General Purpose Command-driven 16-bit
Timer/counter
• Sleep Mode with Wake-up Indication
• Highly Integrated Device for Space Saving
• Each UART is independently controlled with:
■ 16C550 Compatible 5G Register Set
■ 64-byte Transmit and Receive FIFOs
■ Fractional Baud Rate Generator
■ 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
■ RS485 Half-Duplex Control Output with
Selectable Turn-around Delay
■ Infrared (IrDA 1.0) Data Encoder/Decoder
■ Programmable Data Rate with Prescaler
• Up to 8 Mbps Serial Data Rate
• Pin compatible to XR16L784. Same 64-pin LQFP
Package (10x10x1.4 mm)
FIGURE 1. BLOCK DIAGRAM
A7:A0
D7:D0
IOR#
IOW#
CS#
INT#
16/68#
RST#
ENIR
Intel or
Motorola
Data
Bus
Interface
Device
Configuration
Register
s
16-bit
Timer/Counter
*All Inputs are 5V Tolerant
(Except XTAL1)
UART Channel 0
UART
Regs
BRG
64 Byte TX FIFO
TX &
RX
IR
ENDEC
64 Byte RX FIFO
UART Channel 1
UART Channel 2
UART Channel 3
Crystal Osc/
Buffer
2.25V to 3.6V VCC
GND
TX0, RX0, DTR0#,
DSR0#, RTS0#,
CTS0#, CD0#, RI0#
TX3, RX3, DTR3#,
DSR3#, RTS3#,
CTS3#, CD3#, RI3#
XTAL1
XTAL2
TMRCK
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com