xr16c872iq Exar Corporation, xr16c872iq Datasheet - Page 8

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

XR16C872
DTRA#,
DTRB#
RTSA#,
RTSB#
CTSA#,
CTSB#
DSRA#,
DSRB#
CDA#,
CDB#
RIA#,
RIB#
VCC
GND
Name
Rev. 1.00
16,26,36,43 PWR
61,77,98
25,35,42
62,90
Pin
65,
66,
67,
68,
69,
70,
55
56
57
58
59
60
Type
PWR
O
O
I
I
I
I
In IR mode, the output changes to a logic 0 after it is enabled (MCR bit 5=1).
Data Terminal Ready A/B or general purpose output. DTRA/B# are active
llow and associated with UARTchannel A and B. A logic 0 on indicates that
UART A/B is ready. This pin is controlled via the MCR register for channel
A/B. Setting MCR bit-0 to logic 1 puts the output pin to logic 0. This pin will
be a logic 1 after writing a logic 0 to MCR bit-0. This pin has no effect on the
UART transmitter or receiver.
Request to Send A/B or general purpose output. RTSA/B# are active low
outputs and associated with UART channels A/B. Writing a logic 1 to MCR
bit-1sets the pin to a logic 0 and requests remote unit to send data. After a
reset this pin is set to a logic 1. When auto RTS flow control is enabled (EFR
bit-6=1), a logic 0 asks remote modem to send data and a logic 1 requests
to suspend. The user must assert RTS# after enabling auto RTS flow control.
Clear to Send A/B or general purpose input. CTSA/B# are active low
inputs and associated with UART channels A and B. A logic 0 indicates
the remote modem is ready for data. A level change on this input pin will
generate a status change interrupt (MSR bit-0). When auto CTS flow
control is enabled, a logic 1 suspends local data transmission and a logic
0 restarts the local transmitter.
Data Set Read A/B or general purpose input. DSRA/B# are active low inputs
and associated with UARTchannel A and B. A logic 0 on indicates the modem
is ready for data exchange with the UART. A logic level change on this input
pin will generate a status change interrupt (MSR bit-1).This pin has no effect
on the UART’s transmit or receive operation.
Carrier Detect A/B or general purpose input. CDA/B# are active low inputs and
associated with UART channels A and B. A logic 0 on this pin indicates a
carrier signal has been detected by the modem. A logic level change on this
input pin will generate a status change interrupt (MSR bit-3). This pin has no
effect on the UART’s transmit or receive operation.
Ring Indicator A/B or general purpose input. RIA/B# are active low inputs
and associated with UART channels A and B. A logic 0 on indicates the
modem has received a ringing signal from the telephone line. A logic 1
transition on this input pin will generate a status change interrupt (MSR
bit-2). This pin has no effect on UART's transmit or receive operation.
+5 Volts power supply.
Signal ground.
DISCONTINUED
8
Pin Description
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