XR16V654_0709 Datasheet, PDF (6/58 Pages) Exar Corporation – 2.25V TO 3.6V QUAD UART WITH 64-BYTE FIFO

XR16V654/654D
2.25V TO 3.6V QUAD UART WITH 64-BYTE FIFO
Pin Description
REV. 1.0.2
NAME
48-QFN
PIN #
64-LQFP 68-PLCC 80-LQFP 100-QFP
PIN #
PIN#
PIN #
PIN #
TYPE
DESCRIPTION
IOW#
7
(R/W#)
9
18
11
15
I When 16/68# pin is HIGH, it selects Intel
bus interface and this input becomes write
strobe (active low). The falling edge insti-
gates the internal write cycle and the rising
edge transfers the data byte on the data
bus to an internal register pointed by the
address lines.
When 16/68# pin is LOW, the Motorola bus
interface is selected and this input becomes
read (logic 1) and write (logic 0) signal.
CSA#
5
(CS#)
7
16
9
13
I When 16/68# pin is HIGH, this input is chip
select A (active low) to enable channel A in
the device.
When 16/68# pin is LOW, this input
becomes the chip select (active low) for the
Motorola bus interface.
CSB#
9
(A3)
11
20
13
17
I When 16/68# pin is HIGH, this input is chip
select B (active low) to enable channel B in
the device.
When 16/68# pin is LOW, this input
becomes address line A3 which is used for
channel selection in the Motorola bus inter-
face.
CSC#
27
38
50
49
64
I When 16/68# pin is HIGH, this input is chip
(A4)
select C (active low) to enable channel C in
the device.
When 16/68# pin is LOW, this input
becomes address line A4 which is used for
channel selection in the Motorola bus inter-
face.
CSD#
31
42
54
53
68
I When 16/68# pin is HIGH, this input is chip
(VCC)
select D (active low) to enable channel D in
the device.
When 16/68# pin is LOW, this input is not
used and should be connected VCC.
INTA
4
(IRQ#)
6
15
8
12
O When 16/68# pin is HIGH for Intel bus inter-
(OD) ^{face, this ouput becomes channel A inter-}
rupt output. The output state is defined by
the user and through the software setting of
MCR[3]. INTA is set to the active mode
when MCR[3] is set to a logic 1. INTA is set
to the three state mode when MCR[3] is set
to a logic 0 (default). See MCR[3].
When 16/68# pin is LOW for Motorola bus
interface, this output becomes device inter-
rupt output (active low, open drain). An
external pull-up resistor is required for
proper operation.
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