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XR20V2172 Datasheet, PDF (1/51 Pages) Exar Corporation – TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO AND RS232 TRANSCEIVER
PRELIMINARY
XR20V2172
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO AND RS232 TRANSCEIVER
FEBRUARY 2007
REV. P1.0.1
GENERAL DESCRIPTION
The XR20V21721 (V2172) is a high performance two
channel universal asynchronous receiver and
transmitter (UART) with 64 byte TX and RX FIFOs, a
selectable I2C/SPI slave interface and RS232
transceiver. The V2172 operates from 3.3 to 5.5 volts.
The enhanced features in the V2172 include a
programmable fractional baud rate generator, an 8X
and 4X sampling rate that allows for a maximum baud
rate of 1 Mbps at 3.3V. The standard features include
16 selectable TX and RX FIFO trigger levels,
automatic hardware (RTS/CTS) and software (Xon/
Xoff) flow control, and a complete modem interface.
Onboard registers provide the user with operational
status and data error flags. An internal loopback
capability allows system diagnostics. The V2172 is
available in the 64-pin QFN.
NOTE: 1 Covered by U.S. Patent #5,649,122
APPLICATIONS
• Portable Appliances
• Battery-Operated Devices
• Cellular Data Devices
• Factory Automation and Process Controls
FEATURES
• Selectable I2C/SPI Interface
• Meets true EIA/TIA-232-F Standards from +3.3V to
+5.5V operation
• Data rate up to 1 Mbps
• 45us sleep mode exit (charge pump to full power)
• ESD protection for RS-232 I/O pins at
■ +/-15kV - Human Body Model
■ +/-15kV - IEC 1000-4-2, Air-Gap Discharge
■ +/- 8kV - IEC 1000-4-2, Contact Discharge
• Full-featured UART
■ Fractional Baud Rate Generator
■ Transmit and Receive FIFOs of 64 bytes
■ 16 Selectable TX and RX FIFO Trigger Levels
■ Automatic Hardware (RTS/CTS) Flow Control
■ Automatic Software (Xon/Xoff) Flow Control
■ Halt and Resume Transmission Control
■ Automatic sleep mode
■ General Purpose I/Os
■ Full modem interface
• 64-QFN packages
FIGURE 1. XR20V2172 BLOCK DIAGRAM
IR Q #
RESET#
I2 C /S P I#
SDA
SCK
A 0 /C S A #
A 1 /S I
SO
RXB_SEL
C rys ta l
O sc /B u ffe r
BRG
64 Byte
TX & RX
FIFO
Modem
I/O s
Channel A
Channel B
UART
TXA
RXA
RTSA#
DTRA#
CTSA#
DSRA#
R IA #
CDA#
CDB#
R IB #
DSRB#
CTSB#
DTRB#
RTSB#
TXB
RXB
Charge Pump
5K
5K
5K
5K
C h A T ra n sc e iv e r5K
Channel B
T ra n s c e iv e r
R S-232 Transceiver
VREF+
VREF-
TXDA
RXDA
RTSA
DTRA
CTSA
DSRA
R IA
CDA
CDB
R IB
DSRB
CTSB
DTRB
RTSB
TXDB
RXDB
TXB
RXB
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com