xr16c872iq Exar Corporation, xr16c872iq Datasheet - Page 7

• Manufacturer Part Number: xr16c872iq
• Description: Dual Uart With 1284 Parallel Port And Plug-and-play Controller
• Manufacturer: Exar Corporation

MODEM OR SERIAL PORT INTERFACE
Name
BUSY
ERR#
INIT#
PE
SELECT
SELCTIN#
STROBE#
RXA, RXB
TXA, TXB
Rev. 1.00
63,53
64,54
Pin
50
52
45
49
48
44
47
IOP14
IOP14
IOP14
Type
IP24
IP24
IP24
IP24
O
I
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 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# 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# 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 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 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# 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# 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.
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.
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.
DISCONTINUED
7
Pin Description
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XR16C872