XR16M654 Datasheet, PDF (7/58 Pages) Exar Corporation – 1.62V TO 3.63V QUAD UART WITH 64-BYTE FIFO

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Pin Description
XR16M654/654D
1.62V TO 3.63V QUAD UART WITH 64-BYTE FIFO
NAME
48-QFN
PIN #
64-LQFP 68-PLCC 80-LQFP 100-QFP
PIN #
PIN#
PIN #
PIN #
TYPE
DESCRIPTION
INTB
10
12
21
14
18
O When 16/68# pin is HIGH for Intel bus inter-
INTC
26
37
49
48
63
INTD
32
43
55
54
69
(N.C.)
face, these ouputs become the interrupt
outputs for channels B, C, and D. The out-
put state is defined by the user through the
software setting of MCR[3]. The interrupt
outputs are set to the active mode when
MCR[3] is set to a logic 1 and are 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, these outputs are unused and will
stay at logic zero level. Leave these out-
puts unconnected.
INTSEL
38
-
65
67
87
I Interrupt Select (active high, input with
internal pull-down).
When 16/68# pin is HIGH for Intel bus inter-
face, 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 continu-
ous 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 XR16M654D so the INT
outputs operate in the continuous interrupt
mode. This pin is bonded to GND internally
in the XR16M654 and therefore requires
setting MCR bit-3 for enabling the interrupt
output pins.
TXRDYA#
-
-
-
-
5
O ^{UART channels A-D Transmitter Ready}
TXRDYB#
-
-
-
-
25
(active low). The outputs provide the TX
TXRDYC#
-
-
-
-
56
FIFO/THR status for transmit channels A-D.
See Table 5. If these outputs are unused,
TXRDYD#
-
-
-
-
81
leave them unconnected.
RXRDYA#
-
-
-
-
100
O UART channels A-D Receiver Ready
RXRDYB#
-
-
-
-
31
RXRDYC#
-
-
-
-
50
RXRDYD#
-
-
-
-
82
(active low). This output provides the RX
FIFO/RHR status for receive channels A-D.
See Table 5. If these outputs are unused,
leave them unconnected.
TXRDY#
-
-
39
35
45
O Transmitter Ready (active low). This output
is a logically ANDed status of TXRDY# A-
D. See Table 5. If this output is unused,
leave it unconnected.
RXRDY#
-
-
38
34
44
O Receiver Ready (active low). This output is
a logically ANDed status of RXRDY# A-D.
See Table 5. If this output is unused, leave
it unconnected.
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