
á
XR16L2750
2.25V TO 5.5V DUART WITH 64-BYTE FIFO
REV. 1.0.0
4
MODEM OR SERIAL I/O INTERFACE
TXA
13
7
O
UART channel A Transmit Data or infrared encoder data. Standard
transmit and receive interface is enabled when MCR[6] = 0. In this
mode, the TX signal will be a logic 1 during reset or idle (no data). Infra-
red IrDA transmit and receive interface is enabled when MCR[6] = 1. In
the Infrared mode, the inactive state (no data) for the Infrared encoder/
decoder interface is a logic 0. If it is not used, leave it unconnected.
RXA
11
5
I
UART channel A Receive Data or infrared receive data. Normal receive
data input must idle at logic 1 condition. The infrared receiver pulses
typically idles at logic 0 but can be inverted by software control prior
going in to the decoder, see MCR[6] and FCTR[2]. If this pin is not
used, tie it to VCC or pull it high via a 100k ohm resistor.
RTSA#
36
33
O
UART channel A Request-to-Send (active low) or general purpose out-
put. This output must be asserted prior to using auto RTS flow control,
see EFR[6], MCR[1], FCTR[1:0], EMSR[5:4] and IER[6]. For auto
RS485 half-duplex direction control, see FCTR[3] and EMSR[3].
CTSA#
40
38
I
UART channel A Clear-to-Send (active low) or general purpose input.
It can be used for auto CTS flow control, see EFR[7], and IER[7]. This
input should be connected to VCC when not used.
DTRA#
37
34
O
UART channel A Data-Terminal-Ready (active low) or general purpose
output. If it is not used, leave it unconnected.
DSRA#
41
39
I
UART channel A Data-Set-Ready (active low) or general purpose input.
This input should be connected to VCC when not used. This input has
no effect on the UART.
CDA#
42
40
I
UART channel A Carrier-Detect (active low) or general purpose input.
This input should be connected to VCC when not used. This input has
no effect on the UART.
RIA#
43
41
I
UART channel A Ring-Indicator (active low) or general purpose input.
This input should be connected to VCC when not used. This input has
no effect on the UART.
OP2A#
35
32
O
Output Port 2 Channel A - The output state is defined by the user and
through the software setting of MCR[3]. INTA is set to the active mode
and OP2A# output to a logic 0 when MCR[3] is set to a logic 1. INTA is
set to the three state mode and OP2A# to a logic 1 when MCR[3] is set
to a logic 0. See MCR[3]. This output should not be used as a general
output else it will disturb the INTA output functionality.
TXB
14
8
O
UART channel B Transmit Data or infrared encoder data. Standard
transmit and receive interface is enabled when MCR[6] = 0. In this
mode, the TX signal will be a logic 1 during reset or idle (no data). Infra-
red IrDA transmit and receive interface is enabled when MCR[6] = 1. In
the Infrared mode, the inactive state (no data) for the Infrared encoder/
decoder interface is a logic 0. If it is not used, leave it unconnected.
Pin Description
N
AME
44-PLCC
P
IN
#
48-TQFP
P
IN
#
T
YPE
D
ESCRIPTION