xr20m1172 Exar Corporation, xr20m1172 Datasheet - Page 3

• Manufacturer Part Number: xr20m1172
• Description: Two Channel I2c/spi Uart With 64-byte Fifo
• Manufacturer: Exar Corporation

REV. 1.0.0
PIN DESCRIPTIONS
Pin Description
GPIO0/DSRB#
I2C (SPI) INTERFACE
GPIO2/CDB#
GPIO3/RIB#
RTSB#
XTAL1
XTAL2
N
GND
SDA
RXB
RXA
TXA
TXB
SO
AME
32-QFN
P
10
12
13
14
15
IN
11
2
3
4
5
6
7
9
#
28-TSSOP
P
10
11
12
13
14
15
16
17
IN
5
6
7
8
9
#
T
Pwr
I/O
I/O
I/O
YPE
O
O
O
O
O
O
I
I
I
SPI data output pin. If SPI configuration is selected then this pin is a
three-stateable output pin. If I2C-bus configuration is selected, this pin
is undefined and must be left unconnected.
I
selected, then this pin is undefined and must be connected to VCC.
UART Receive Data or Infrared Receive Data. UART receive data
input must idle HIGH. Infrared receive data input must idle LOW. If this
pin is not used, tie it to VCC or pull it high via a 100k ohm resistor.
UART Receive Data or Infrared Receive Data. UART receive data
input must idle HIGH. Infrared receive data input must idle LOW. If this
pin is not used, tie it to VCC or pull it high via a 100k ohm resistor.
UART Transmit Data or Infrared Encoder Data. In the standard UART
Transmit Data mode, the TX signal will be HIGH during reset or idle
(no data). In the Infrared mode, the inactive state (no data) for the
Infrared encoder/decoder interface is LOW. If ithis pin is not used, it
should be left unconnected.
UART Transmit Data or Infrared Encoder Data. In the standard UART
Transmit Data mode, the TX signal will be HIGH during reset or idle
(no data). In the Infrared mode, the inactive state (no data) for the
Infrared encoder/decoder interface is LOW. If ithis pin is not used, it
should be left unconnected.
Crystal or external clock input.
Crystal or buffered clock output.
General purpose I/O pin or UART Carrier-Detect. If this pin is an input
and is unused, it should be connected to VCC or GND. If this pin is an
output and is unused, it should be left unconnected. See IOControl[1]
and IODir register.
Power supply common, ground.
General purpose I/O pin or UART Data-Set-Ready. If this pin is an
input and is unused, it should be connected to VCC or GND. If this pin
is an output and is unused, it should be left unconnected. See IOCon-
trol[1] and IODir register.
General purpose I/O pin or UART Ring-Indicator. If this pin is an input
and is unused, it should be connected to VCC or GND. If this pin is an
output and is unused, it should be left unconnected. See IOControl[1]
and IODir register.
UART Request-To-Send. This output can be used for Auto RTS Hard-
ware Flow Control, Auto RS-485 Half-Duplex direction control or as a
general purpose output. If unused, this pin should be left uncon-
nected.
2
C-bus data input/output (open-drain). If SPI configuration is
3
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO
D
ESCRIPTION
XR20M1172