XR20V2172
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO AND RS232 TRANSCEIVER
REV. 1.0.1
JULY 2008
FEATURES
GENERAL DESCRIPTION
• Selectable I2C/SPI Interface
1
The XR20V2172 (V2172) is a high performance two
channel universal asynchronous receiver and
transmitter (UART) with 64 byte TX and RX FIFOs, a
• Meets true EIA/TIA-232-F Standards from +3.3V to
+5.5V operation
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.
• 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 61000-4-2, Air-Gap Discharge
■ +/- 8kV - IEC 61000-4-2, 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
NOTE: 1 Covered by U.S. Patent #5,649,122
APPLICATIONS
• Portable Appliances
• Battery-Operated Devices
• Cellular Data Devices
■ General Purpose I/Os
■ Full modem interface
• Factory Automation and Process Controls
• 64-QFN packages
FIGURE 1. XR20V2172 BLOCK DIAGRAM
VREF+
Crystal
Osc/Buffer
BRG
64 Byte
TX & RX
FIFO
Charge Pump
IRQ#
VREF-
TXDA
RESET#
TXA
RXA
RXDA
5K
RTSA#
RTSA
DTRA#
CTSA#
DTRA
CTSA
I2C/SPI#
SDA
5K
5K
Modem
I/Os
DSRA#
RIA#
DSRA
RIA
5K
5K
SCK
CDA#
CDA
Channel A
Ch A Transceiver
A0/CSA#
A1/SI
SO
CDB#
RIB#
CDB
RIB
DSRB#
CTSB#
DTRB#
RTSB#
TXB
DSRB
CTSB
DTRB
RTSB
TXDB
RXDB
TXB
Channel B
Channel B
Transceiver
RXB
RXB_SEL
RXB
UART
RS-232 Transceiver
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com