XR16V2552_07 Datasheet, PDF (5/48 Pages) Exar Corporation – HIGH PERFORMANCE DUART WITH 16-BYTE FIFO

REV. 1.0.2
Pin Description
NAME
CTSB#
32-QFN
PIN #
17
DTRB#
-
DSRB#
-
CDB#
-
RIB#
-
MFB#
-
XR16V2552
HIGH PERFORMANCE DUART WITH 16-BYTE FIFO
44-PLCC
PIN #
28
27
29
30
31
19
TYPE
DESCRIPTION
I UART channel B Clear-to-Send (active low) or general purpose input.
It can be used for auto CTS flow control, see EFR[7], and IER[7]. This
input should be connected to VCC when not used.
O UART channel B Data-Terminal-Ready (active low) or general purpose
output. If this pin is not used, leave it unconnected.
I UART channel B Data-Set-Ready (active low) or general purpose input.
This input should be connected to VCC when not used. This input has
no effect on the UART.
I _{UART channel B Carrier-Detect (active low) or general purpose input.}
This input should be connected to VCC when not used. This input has
no effect on the UART.
I _{UART channel B Ring-Indicator (active low) or general purpose input.}
This input should be connected to VCC when not used. This input has
no effect on the UART.
O Multi-Function Output Channel B. This output pin can function as the
OP2B#, BAUDOUTB#, or RXRDYB# pin. One of these output signal
functions can be selected by the user programmable bits 1-2 of the
Alternate Function Register (AFR). These signal functions are
described as follows:
1) OP2B# - When OP2B# (active low) is selected, the MF# pin is LOW
when MCR bit-3 is set HIGH (see MCR bit-3). MCR bit-3 defaults to a
logic 0 condition after a reset or power-up.
2) BAUDOUTB# - When BAUDOUTB# function is selected, the Baud
rate clock output is available at this pin.
ANCILLARY SIGNALS
XTAL1
4
11
XTAL2
5
13
RESET
12
21
VCC
GND
GND
26
20
Center Pad
44, 33
22, 12
N/A
NC
18, 19
-
3) RXRDYB# - RXRDYB# (active low) is intended for monitoring block
data transfers. See Table 2 for more details.
I Crystal or external clock input.
O Crystal or buffered clock output.
I _{Reset (active high) - A longer than 40 ns HIGH pulse on this pin will}
reset the internal registers and all outputs. The UART transmitter out-
put will be held HIGH, the receiver input will be ignored and outputs are
reset during reset period (see Table 15).
Pwr 2.25 to 3.6V power supply. All input pins are 5V tolerant.
Pwr Power supply common, ground.
Pwr _{The center pad on the backside of the 32-QFN package is metallic and}
should be connected to GND on the PCB. The thermal pad size on the
PCB should be the approximate 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.
- No Connect.
Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
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