XR16L784 Exar Corporation, XR16L784 Datasheet - Page 3

• Manufacturer Part Number: XR16L784
• Description: High Performance 5V And 3.3V Quad Uart
• Manufacturer: Exar Corporation

PIN DESCRIPTIONS
Pin Description
DATA BUS INTERFACE
MODEM OR SERIAL I/O INTERFACE
(R/W#)
RTS0#
CTS0#
DTR0#
D7:D0
A7-A0
IOW#
N
IOR#
INT#
CS#
RX0
TX0
AME
6-1,64,63
18-11
P
62
61
53
60
55
59
54
IN
7
8
#
T
OD
YPE
IO
O
O
O
I
I
I
I
I
I
Address data lines [7:0]. A0:A3 selects individual UART’s 16 configuration
registers, A4:A6 selects UART channel 0 to3, and A7 selects the global
device configuration registers
Data bus lines (7:0] (bidirectional).
When 16/68# pin is at logic 1, it selects Intel bus interface and this input is
read strobe (active low). The falling edge instigates an internal read cycle and
retrieves the data byte from an internal register pointed by the address lines
[A7:A0], puts it on the data bus to allow the host processor to read it on the
leading edge.
When 16/68# pin is at logic 0, it selects Motorola bus interface and this input
should be connected to VCC.
When 16/68# pin is at logic 1, it selects Intel bus interface and this input
becomes write strobe (active low). The falling edge instigates the internal
write cycle and the leading edge transfers the data byte on the data bus to an
internal register pointed by the address lines.
When 16/68# pin is at logic 0, it selects Motorola bus interface and this input
becomes read (logic 1) and write (logic 0) signal.
When 16/68# pin is at logic 1, this input is chip select (active low) to enable
the XR16L784 device.
When 16/68# pin is at logic 0, this input becomes the read and write strobe
(active low) for the Motorola bus interface.
Global interrupt output from XR16L784 (open drain, active low). This output
requires an external pull-up resistor (47K-100K ohms) to operate properly. It
may be shared with other devices in the system to form a single interrupt line
to the host processor and have the software driver polls each device for the
interrupt status.
UART channel 0 Transmit Data or infrared transmit data.
UART channel 0 Receive Data or infrared receive data. Normal RXD input
idles at logic 1 condition. The infrared pulses can be inverted internally prior
to the decoder by FCTR[4].
UART channel 0 Request to Send or general purpose output (active low).
This port must be asserted prior using for one of two functions:
1) auto RTS flow control, see EFR bit-6, MCR bits-1 & 2, FCTR bits 0-3 and
2) Auto RS485 half-duplex direction control, see FCTR bit-5, MCR bit-2 and
UART channel 0 Clear to Send or general purpose input (active low). It can be
used for auto CTS flow control, see EFR bit-7, MCR bit-2 and IER bit-7.
UART channel 0 Data Terminal Ready or general purpose output (active low).
This port must be asserted prior using for one of two functions:
1) auto DTR flow control, see EFR bit-6, FCTR bits-0 to 3, MCR bits-0 & 2,
2) Auto RS485 half-duplex direction control, see FCTR bit-5, MCR bit-2 and
IER bit-6
MSR bits 4-7.
and IER bit-6
MSR bit 4-7.
3
HIGH PERFORMANCE 5V AND 3.3V QUAD UART
D
ESCRIPTION
XR16L784
REV. 1.0.1