xr16v554 Exar Corporation, xr16v554 Datasheet - Page 7

• Manufacturer Part Number: xr16v554
• Description: 2.25v To 3.6v Quad Uart With 16-byte Fifo
• Manufacturer: Exar Corporation

Pin Description
REV. 1.0.2
ANCILLARY SIGNALS
(RESET#)
RESET
16/68#
XTAL1
XTAL2
CDA#
CDB#
CDC#
CDD#
N
RIA#
RIB#
RIC#
RID#
GND
GND
VCC
AME
2, 24, 37 4, 21, 35,
48-QFN
Center
21, 47
P
Pad
18
19
14
20
IN
-
-
-
-
-
-
-
-
#
64-LQFP
14, 28,
45, 61
P
N/A
64
18
31
49
63
19
30
50
25
26
27
52
IN
-
#
68-PLCC
6, 23, 40,
13, 30,
47, 64
P
N/A
27
43
61
28
42
62
35
36
31
37
57
IN
9
8
#
80-LQFP
5, 25, 45,
16, 36,
56, 76
P
N/A
19
42
59
18
43
58
50
51
53
65
IN
2
3
-
#
T
Pwr 2.25V to 3.6V power supply. All inputs, except XTAL1,
Pwr Power supply common, ground.
Pwr The center pad on the backside of the QFN package is
7
YPE
O
I
I
I
I
I
2.25V TO 3.6V QUAD UART WITH 16-BYTE FIFO
UART channels A-D Carrier-Detect (active low) or gen-
eral purpose input. This input should be connected to
VCC when not used. This input has no effect on the
UART.
UART channels A-D Ring-Indicator (active low) or gen-
eral purpose input. This input should be connected to
VCC when not used. This input has no effect on the
UART.
Crystal or external clock input. Caution: this input is not
5V tolerant.
Crystal or buffered clock output.
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 Motorola bus type of interface.
Motorola bus interface is not available on the 64 pin
package.
When 16/68# pin is HIGH for Intel bus interface, this
input becomes the Reset pin (active high). In this case,
a 40 ns minimum HIGH pulse on this pin will reset the
internal registers and all outputs. The UART transmitter
output will be held HIGH, the receiver input will be
ignored and outputs are reset during reset period
(Table
bus interface, this input becomes Reset# pin (active
low). This pin functions similarly, but instead of a HIGH
pulse, a 40 ns minimum LOW pulse will reset the inter-
nal registers and outputs.
Motorola bus interface is not available on the 64 pin
package.
are 5V tolerant.
metallic and should be connected to GND on the PCB.
The thermal pad size on the PCB should be the approx-
imate size of this center pad and should be solder mask
defined. The solder mask opening should be at least
0.0025" inwards from the edge of the PCB thermal pad.
13). When 16/68# pin is at LOW for Motorola
D
ESCRIPTION
XR16V554/554D