xr16c850im Exar Corporation, xr16c850im Datasheet - Page 6

• Manufacturer Part Number: xr16c850im
• Description: Uart With 128-byte Fifos And Infrared Irda Encoder/decoder
• Manufacturer: Exar Corporation

XR16C850
2.97V TO 5.5V UART WITH 128-BYTE FIFO
MODEM OR SERIAL I/O INTERFACE
ANCILLARY SIGNALS
LPT2#
XTAL1
XTAL2
DSR#
RTS#
CTS#
DTR#
N
CD#
SEL
RI#
RX
TX
AME
44-P
PLCC
26
13
36
40
37
41
42
43
18
19
34
11
IN
48-P
TQFP
22
32
38
33
39
40
41
14
15
36
8
7
IN
T
YPE
O
O
O
O
O
I
I
I
I
I
I
I
Line Printer Port-2 Decode Logic Output (active low) - This pin functions as the PC
standard LPT-2 printer port address decode logic output, see
Bus Mode, LPT2# becomes DDIS#/D12.
Transmit Data or wireless infrared transmit data. This output is active low in normal
standard serial interface operation (RS-232, RS-422 or RS-485) and active high in
the infrared mode. Infrared mode can be enabled by connecting pin ENIR to VCC
or through software selection after power up.
Receive Data or wireless infrared receive data. Normal received data input idles at
logic 1 condition and logic 0 in the infrared mode. The wireless infrared pulses are
applied to the decoder. This input must be connected to its idle logic state in either
normal, logic 1, or infrared mode, logic 0, else the receiver may report “receive
break” and/or “error” condition(s).
Request to Send or general purpose output (active low). This port may be used for
automatic hardware flow control, see EFR bit-6, MCR bit-1, FCTR bits 0-1 and IER
bit-6. RTS# output must be asserted before auto RTS flow control can start. If this
pin is not needed for modem communication, then it can be used as a general I/O.
If it is not used, leave it unconnected.
Clear to Send or general purpose input (active low). If used for automatic hardware
flow control, data transmission will be stopped when this pin is de-asserted and will
resume when this pin is asserted again. See EFR bit-7, MCR bit-2 and IER bit-7. If
this pin is not needed for modem communication, then it can be used as a general
I/O. If it is not used, connect it to VCC.
Data Terminal Ready or general purpose output (active low). If this pin is not
needed for modem communication, then it can be used as a general I/O. If it is not
used, leave it unconnected.
Data Set Ready input or general purpose input (active low). If this pin is not
needed for modem communication, then it can be used as a general I/O. If it is not
used, connect it to VCC.
Carrier Detect input or general purpose input (active low). If this pin is not needed
for modem communication, then it can be used as a general I/O. If it is not used,
connect it to VCC.
Ring Indicator input or general purpose input (active low). If this pin is not needed
for modem communication, then it can be used as a general I/O. If it is not used,
connect it to VCC.
Crystal or external clock input. See
Caution: this input is not 5V tolerant.
Crystal or buffered clock output. See
PC Mode Select (active low). When this input is at logic 0, it enables the on-board
chip select decode function according to PC ISA bus COM[4:1] and IRQ[4,3] port
definitions. See
This pin is not available on the 40 pin PDIP packages which operate in the Intel
Bus Mode only.
Table 3
6
for details. This pin has an internal 100kΩ pull-up resistor.
D
Figure 7
ESCRIPTION
Figure 7
for typical oscillator connections.
for typical oscillator connections.
Table 1
xr
. During Intel
REV. 2.3.1