XR16V654_0709 Datasheet, PDF (9/58 Pages) Exar Corporation – 2.25V TO 3.6V QUAD UART WITH 64-BYTE FIFO

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Pin Description
XR16V654/654D
2.25V TO 3.6V QUAD UART WITH 64-BYTE FIFO
NAME
48-QFN
PIN #
64-LQFP 68-PLCC 80-LQFP 100-QFP
PIN #
PIN#
PIN #
PIN #
TYPE
DESCRIPTION
DSRA#
-
DSRB#
-
DSRC#
-
DSRD#
-
1
10
3
7
I UART channels A-D Data-Set-Ready
17
26
19
23
32
44
43
58
48
60
59
74
(active low) or general purpose input. This
input should be connected to VCC when
not used. This input has no effect on the
UART.
CDA#
-
CDB#
-
CDC#
-
CDD#
-
64
9
79
99
I UART channels A-D Carrier-Detect (active
18
27
23
32
31
43
39
49
49
61
63
83
low) or general purpose input. This input
should be connected to VCC when not
used. This input has no effect on the UART.
RIA#
-
63
8
78
98
I UART channels A-D Ring-Indicator (active
RIB#
-
19
28
24
33
RIC#
-
30
42
38
48
RID#
-
50
62
64
84
low) or general purpose input. This input
should be connected to VCC when not
used. This input has no effect on the UART.
ANCILLARY SIGNALS
XTAL1
18
25
35
31
40
I Crystal or external clock input. Caution: this
input is not 5V tolerant.
XTAL2
19
26
36
32
41
O Crystal or buffered clock output.
16/68#
14
-
31
-
36
I Intel or Motorola Bus Select (input with
internal pull-up).
When 16/68# pin is HIGH, 16 or Intel Mode,
the device will operate in the Intel bus type
of interface.
When 16/68# pin is LOW, 68 or Motorola
mode, the device will operate in the Motor-
ola bus type of interface.
Motorola bus interface is not available on
the 64 pin package.
CLKSEL
-
21
30
26
35
I Baud-Rate-Generator Input Clock Pres-
caler Select for channels A-D. This input is
only sampled during power up or a reset.
Connect to VCC for divide by 1 (default)
and GND for divide by 4. MCR[7] can over-
ride the state of this pin following a reset or
initialization. See MCR bit-7 and Figure 7
in the Baud Rate Generator section.
CHCCLK
-
-
-
-
42
I This input provides the clock for UART
channel C. An external 16X baud clock or
the crystal oscillator’s output, XTAL2, must
be connected to this pin for normal opera-
tion. This input may also be used with MIDI
(Musical Instrument Digital Interface) appli-
cations when an external MIDI clock is pro-
vided. This pin is only available in the 100-
pin QFP package.
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