Enhanced 1-CH Full-Speed USB UART
XR21B1411
Single Channel USB UART with Industry’s Smallest Package
and Optimized Software Drivers
The XR21B1411 (B1411) is an enhanced 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.
The B1411 operates from an internal clock that is programmable to 6, 12, 24 or
48 MHz. Therefore, no external crystal / oscillator is required as in previous
generation UARTs. With the fractional baud rate generator, any baud rate up to
12 Mbps can be accurately generated using the internal clock.
The large 128-byte TX FIFO and 384-byte RX FIFO of the B1411 help 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 further simplifies typical
multidrop RS-485 applications.
The Vendor ID, Product ID, bus-powered mode, self-powered mode, remote
wakeup support or maximum power consumption values, as well as default
baud rate settings can be programmed using the on-board OTP through the
USBD+ / USBD- pins.
The B1411 operates from a single 5V power supply and is available in a 16-pin
QFN package.
Software drivers for Windows 7, 2000, XP, Vista, and CE, as well as Linux and
Mac are supported for the XR21B1411.
FeATUReS
•
±15kV HBM ESD on
USBD+/USBD-
•
USB 2.0 Compliant Interface
Supports 12 Mbps USB
full-speed data rate
Supports USB suspend, resume
and remote wakeup operations
•
Enhanced UART Features
Data rates up to 12 Mbps
Fractional Baud Rate Generator
128 byte TX FIFO
384 byte RX FIFO
7, 8 or 9 data bits
1 or 2 stop bits
Odd, even, mark, space
or no parity
Automatic Hardware (RTS/CTS
or DTR/DSR) Flow Control
Automatic Software (Xon/Xoff)
Flow Control
Multidrop mode
Auto Transceiver Control
Half-Duplex mode
Selectable GPIO or Modem I/O
•
Internal 48 MHz clock with
clock divisors programmable
down to 6 MHz
•
Single 5V power supply
•
16-pin QFN package
•
Virtual COM Port drivers
Windows 7, 2000, XP and
Vista
Windows CE 4.2, 5.0, 6.0
Linux
Mac
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