xr16m654 Exar Corporation, xr16m654 Datasheet - Page 6

• Manufacturer Part Number: xr16m654
• Description: 1.62v To 3.63v Quad Uart With 64-byte Fifo
• Manufacturer: Exar Corporation

XR16M654/654D
1.62V TO 3.63V QUAD UART WITH 64-BYTE FIFO
Pin Description
(R/W#)
(IRQ#)
(VCC)
CSA#
(CS#)
CSB#
CSC#
CSD#
N
IOW#
INTA
(A3)
(A4)
AME
48-QFN
P
27
31
IN
7
5
9
4
#
64-LQFP
P
11
38
42
IN
9
7
6
#
68-PLCC
P
18
16
20
50
54
15
IN
#
80-LQFP
P
13
49
53
IN
11
9
8
#
100-QFP
6
P
15
13
17
64
68
12
IN
#
(OD)
T
YPE
O
I
I
I
I
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.
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.
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.
When 16/68# pin is HIGH, this input is chip
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.
When 16/68# pin is HIGH, this input is chip
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.
When 16/68# pin is HIGH for Intel bus inter-
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.
D
ESCRIPTION
REV. 1.0.0