XR16L788 Exar Corporation, XR16L788 Datasheet - Page 3

• Manufacturer Part Number: XR16L788
• Description: High-performance 3.3V Octal Uart
• Manufacturer: Exar Corporation

XR16L788 OCTAL UART
REV. 1.1.4
PIN DESCRIPTIONS
DATA BUS INTERFACE
MODEM OR SERIAL I/O INTERFACE
DTR0#
DSR0#
RTS0#
CTS0#
A7-A0
D7:D0
N
IOW#
CD0#
IOR#
INT#
CS#
RX0
TX0
AME
20-27
P
5-12
100
19
13
30
16
93
95
99
94
98
97
IN
#
T
OD
YPE
IO
O
O
O
I
I
I
I
I
I
I
I
Address data lines [7:0]. A0:A3 selects individual UART’s 16 configuration reg-
isters, A4:A6 selects UART channel 0 to7, and A7 selects the global device
configuration registers.
Global interrupt output from XR16L788 (open drain, active low). This output
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], places 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 (R/W#).
When 16/68# pin is at logic 1, this input is chip select (active low) to enable
the XR16L788 device.
When 16/68# pin is at logic 0, this input becomes the read and write strobe
(active low) for the Motorola bus interface.
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
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
2) RS485 half-duplex direction control, see FCTR bit-5, MCR bit-2 and MSR
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) RS485 half-duplex direction control, see FCTR bit-5, MCR bit-2 and MSR
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.
UART channel 0 Carrier Detect or general purpose input (active low).
and IER bit-6
bits 4-7.
2, and IER bit-6
bit 4-7.
3
D
ESCRIPTION