xr16c2850im Exar Corporation, xr16c2850im Datasheet - Page 4

• Manufacturer Part Number: xr16c2850im
• Description: Dual Uart With Tx And Rx Fifo Counters, 128 Bytes Of Fifos And Automatic Rs-485 Half Duplex Control
• Manufacturer: Exar Corporation

XR16C2850
2.97V TO 5.5V DUAL UART WITH 128-BYTE FIFOS
MODEM OR SERIAL I/O INTERFACE
RXRDYB#
DSRA#
RTSA#
CTSA#
DTRA#
OP2A#
CDA#
N
RIA#
RXA
TXA
TXB
AME
44-PLCC
P
23
13
36
40
37
41
42
43
35
14
IN
11
#
48-TQFP
P
18
33
38
34
39
40
41
32
IN
7
5
8
#
T
YPE
O
O
O
O
O
O
I
I
I
I
I
UART channel B Receiver Ready (active low). This output provides the
RX FIFO/RHR status for receive channel B. See
is not used, leave it unconnected.
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 HIGH during reset or idle (no data). Infrared
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 isLOW. If this output is not used, leave it uncon-
nected.
UART channel A Receive Data or infrared receive data. Normal receive
data input must idle HIGH. The infrared receiver pulses typically idles
LOW 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.
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]. If this output is not
used, leave it unconnected.
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.
UART channel A Data-Terminal-Ready (active low) or general purpose
output. If this output is not used, leave it unconnected.
UART channel A Data-Set-Ready (active low) or general purpose input.
This input should be connected to VCC when not used.
UART channel A Carrier-Detect (active low) or general purpose input.
This input should be connected to VCC when not used.
UART channel A Ring-Indicator (active low) or general purpose input.
This input should be connected to VCC when not used.
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 is LOW when MCR[3] is set to a logic 1. INTA is set
to the three state mode and OP2A# is HIGH when MCR[3] is set to a
logic 0. See MCR[3]. This output can only be used as a general pur-
pose output when interrupts are not used, otherwise it will disturb the
INTA output functionality. If this output is not used, leave it uncon-
nected.
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 HIGH during reset or idle (no data). Infrared
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 LOW. If this output is not used, leave it uncon-
nected.
4
D
ESCRIPTION
Table 2
xr
. If this output
REV. 2.1.3