XR16L788IQ-F Datasheet, PDF (3/54 Pages) Exar Corporation – HIGH PERFORMANCE 2.97V TO 5.5V OCTAL UART

REV. 1.2.3
PIN DESCRIPTIONS
XR16L788
HIGH PERFORMANCE 2.97V TO 5.5V OCTAL UART
NAME
PIN #
TYPE
DESCRIPTION
DATA BUS INTERFACE
A7:A0
20-27
I
D7:D0
IOR#
5-12
IO
19
I
IOW#
13
I
CS#
INT#
30
I
16
OD
MODEM OR SERIAL I/O INTERFACE
TX0
93
O
RX0
100
I
RTS0#
95
O
CTS0#
DTR0#
99
I
94
O
DSR0#
98
I
Address data lines [7:0]. A0:A3 selects individual UART’s 16 configuration
registers, A4:A6 selects UART channel 0 to7, and A7 selects the global device
configuration registers.
Data bus lines (7:0] (bidirectional).
When 16/68# pin is HIGH, 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], places it on the data bus to allow the host processor to read it on the
leading edge.
When 16/68# pin is LOW, it selects Motorola bus interface and this input
should be connected to VCC.
When 16/68# pin is HIGH, 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 LOW, it selects Motorola bus interface and this input
becomes read (HIGH) and write (LOW) signal (R/W#).
When 16/68# pin is HIGH, this input is chip select (active low) to enable the
XR16L788 device.
When 16/68# pin is LOW, this input becomes the read and write strobe (active
low) for the Motorola bus interface.
Global interrupt output from XR16L788 (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 HIGH. The infrared pulses can be inverted internally prior the decoder by
FCTR[4].
UART channel 0 Request to Send or general purpose output (active low). This
port may be used for one of two functions:
1) auto hardware flow control, see EFR bit-6, MCR bits-1 & 2, FCTR bits 0-3
and IER bit-6
2) RS485 half-duplex direction control, see FCTR bit-5, MCR bit-2 and MSR
bits 4-7.
UART channel 0 Clear to Send or general purpose input (active low). It can be
used for auto hardware 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 may be used one of two functions.
1) auto hardware flow control, see EFR bit-6, FCTR bits-0 to 3, MCR bits-0 &
2, and IER bit-6
2) RS485 half-duplex direction control, see FCTR bit-5, MCR bit-2 and MSR
bit 4-7.
UART channel 0 Data Set Ready or general purpose input (active low). It can
be used for auto hardware flow control, see EFR bit-7, MCR bit-2 and IER bit-
7.
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