XR21V1412
2-CH FULL-SPEED USB UART
REV. 1.1.0
SEPTEMBER 2010
GENERAL DESCRIPTION
FEATURES
The XR21V1412 (V1412) is an enhanced 2-channel
Universal Asynchronous Receiver and Transmitter
(UART) with a USB interface. The USB interface is
fully compliant to Full Speed USB 2.0 specification
that supports 12 Mbps USB data transfer rate. The
USB interface also supports USB suspend, resume
and remote wakeup operations.
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USB 2.0 Compliant, Full-Speed (12 Mbps)
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Supports USB suspend, resume and remote
wakeup operations
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Enhanced Features of each UART
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Data rates up to 12 Mbps
Fractional Baud Rate Generator
128 byte TX FIFO
The V1412 operates from an internal 48MHz clock
therefore no external crystal/oscillator is required like
previous generation UARTs. With the fractional baud
rate generator, any baud rate can accurately be
generated using the internal 48MHz clock.
384 byte RX FIFO
7, 8 or 9 data bits
1 or 2 stop bits
The large 128-byte TX FIFO and 384-byte RX FIFO
of the V1412 helps to optimize the overall data
throughput for various applications. The Automatic
Transceiver Direction control feature simplifies both
the hardware and software for half-duplex RS-485
applications. If required, the multidrop (9-bit) mode
with automatic half-duplex transceiver control feature
Odd, even, mark, space or no parity
Automatic Hardware (RTS/CTS or DTR/DSR)
Flow Control
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Automatic Software (Xon/Xoff) Flow Control
Multidrop mode
further
simplifies
typical
multidrop
RS-485
Auto Transceiver Enable
Half-Duplex mode
applications.
The V1412 operates from a single 2.97 to 3.63 volt
power supply and has 5V tolerant inputs. The V1412
is available in a 32-pin QFN package.
Selectable GPIO or Modem I/O
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Internal 48 MHz clock
Single 2.97-3.63V power supply
5V tolerant inputs
WHQL certified software drivers for Windows 2000,
XP, Vista, 7, and CE, as well as Linux and Mac are
supported for the XR21V1412.
32-pin QFN package
APPLICATIONS
Virtual COM Port WHQL certified drivers
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Portable Appliances
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Windows 2000, XP, Vista and 7
Windows CE 4.2, 5.0, 6.0
External Converters (dongles)
Battery-Operated Devices
Cellular Data Devices
Linux
Mac
Factory Automation and Process Controls
Industrial applications
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com