XR16V554 Datasheet, PDF (6/45 Pages) Exar Corporation – 2.25V TO 3.6V QUAD UART WITH 16-BYTE FIFO

XR16V554/554D
2.25V TO 3.6V QUAD UART WITH 16-BYTE FIFO
Pin Description
REV. 1.0.1
NAME
48-QFN
PIN #
64-LQFP
PIN #
68-PLCC
PIN#
80-LQFP
PIN #
TYPE
DESCRIPTION
INTSEL
38
-
65
67
I Interrupt Select (active high, input with internal pull-
down).
When 16/68# pin is HIGH for Intel bus interface, this pin
can be used in conjunction with MCR bit-3 to enable or
disable the INT A-D pins or override MCR bit-3 and
enable the interrupt outputs. Interrupt outputs are
enabled continuously when this pin is HIGH. MCR bit-3
enables and disables the interrupt output pins. In this
mode, MCR bit-3 is set to a logic 1 to enable the contin-
uous output. See MCR bit-3 description for full detail.
This pin must be LOW in the Motorola bus interface
mode. For the 64 pin packages, this pin is bonded to
VCC internally in the XR16V554D so the INT outputs
operate in the continuous interrupt mode. This pin is
bonded to GND internally in the XR16V554 and there-
fore requires setting MCR bit-3 for enabling the inter-
rupt output pins.
MODEM OR SERIAL I/O INTERFACE
TXA
6
8
17
10
O UART channels A-D Transmit Data and infrared trans-
TXB
8
10
19
12
TXC
28
39
51
50
mit data. In this mode, the TX signal will be HIGH dur-
ing reset, or idle (no data).
TXD
30
41
53
52
RXA
48
62
7
77
I UART channel A-D Receive Data. Normal receive data
RXB
13
20
29
25
input must idle HIGH.
RXC
22
29
41
37
RXD
36
51
63
65
RTSA#
3
5
14
7
O UART channels A-D Request-to-Send (active low) or
RTSB#
11
13
22
15
RTSC#
25
36
48
47
general purpose output. If these outputs are not used,
leave them unconnected.
RTSD#
33
44
56
55
CTSA#
1
2
11
4
I UART channels A-D Clear-to-Send (active low) or gen-
CTSB#
12
16
25
18
CTSC#
23
33
45
44
eral purpose input. These inputs should be connected
to VCC when not used.
CTSD#
35
47
59
58
DTRA#
-
DTRB#
-
DTRC#
-
DTRD#
-
3
12
5
O UART channels A-D Data-Terminal-Ready (active low)
15
24
17
34
46
45
or general purpose output. If these outputs are not
used, leave them unconnected.
46
58
57
DSRA#
-
DSRB#
-
DSRC#
-
DSRD#
-
1
10
3
I UART channels A-D Data-Set-Ready (active low) or
17
26
19
32
44
43
48
60
59
general purpose input. This input should be connected
to VCC when not used. This input has no effect on the
UART.
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