XR16C872 Datasheet, PDF (7/60 Pages) Exar Corporation – DUAL UART WITH 1284 PARALLEL PORT AND PLUG-AND-PLAY CONTROLLER

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XR16C872
Name
Pin Type
Pin Description
parallel port. An output logic 0 indicates the parallel port is operating as an
output port and a logic 1 indicates it is an input port.
BUSY
50 IP24 BUSY is an active high printer busy indicator or general purpose input.
Generally, it is used as an input from the printer and a logic 1 indicates it is
not ready. The input has an internal weak pull-up resistor.
ERR#
52 IP24 ERR# is printer error indicator or a general purpose input. Generally, it is used
as an input from the printer and a logic 0 indicates it has an error condition.
The input has a weak internal pull-up resistor.
INIT#
45 IOP14 INIT# is a printer initialization signal or a general purpose output. Generally,
it is used with the printer (active low) for system initialization or reset. The pin
is a tri-state output and has an internal weak pull-up resistor.
PE
49 IP24 PE is a signal from the printer indicating a paper empty condition or general
purpose input. Generally, it is used with a printer and a logic 1 indicates the
printer is out of paper. This input has an internal weak pull-up resistor.
SELECT
48 IP24 SELECT is the printer select status indicat to the host or general purpose
input. Normally this pin is connected to a printer output and a logic 0 indicates
the ready status of the printer, i.e., on-line and/or on-line and ready condiftion.
This pin has an internal weak pull-up resistor.
SELCTIN#
44 IOP14 SELCTIN# is a select signal to the printer or general purpose I/O pin. This
pin can be read via bit-3 in the printer command register, or written via bit-3
in the printer control register. Normally this signal is connected to a printer
to select the printer with an active low signal. The pin is tri-state output and
has an internal weak pull-up resistor.
STROBE#
47 IOP14 STROBE# is a data strobe output or general purpose I/O pin. Normally this
output is connected to a printer and indicates that valid data is available on
the data bus (PD0-PD7). The pin is a tri-state output with an intenal weak pull-
up resistor.
MODEM OR SERIAL PORT INTERFACE
RXA, RXB
63,53
I
Receive Data A/B. Serial receive data or IR pulses input to UART channel A
and B. The RX signal to the UART should be a logic 1 state during reset, idle
(no data) and sleep mode. During the local loop-back mode, the RX input pins
are disabled and TX data is internally connected to the UART RX Inputs. In
the IR mode, this input is normally at logic 0.
TXA, TXB
64,54 O Transmit Data A/B. Serial transmitt data or IR pulses output from channel A
and B. The normal output is a logic 1 for serial data during reset, idle (no data),
sleep mode, or when the transmitter is disabled. During the local loop-back
mode, the TX output pin is held at logic 1and internally it connects to RX input.
Rev. 1.00
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