XR16M2650 Datasheet, PDF (5/47 Pages) Exar Corporation – HIGH PERFORMANCE LOW VOLTAGE DUART WITH 32-BYTE FIFO

REV. 1.0.2
Pin Description
XR16M2650
HIGH PERFORMANCE LOW VOLTAGE DUART WITH 32-BYTE FIFO
NAME
RTSB#
32-QFN
PIN #
15
48-TQFP
PIN #
22
CTSB#
16
23
DTRB#
-
35
DSRB#
-
20
CDB#
-
16
RIB#
-
21
OP2B#
-
9
ANCILLARY SIGNALS
XTAL1
10
13
XTAL2
11
14
RESET
24
36
VCC
26
42
GND
13
17
GND Center Pad
N/A
NC
9, 17 12, 24, 25,
37
TYPE
DESCRIPTION
O _{UART channel B Request-to-Send (active low) or general purpose out-}
put. This port must be asserted prior to using auto RTS flow control,
see EFR[6], MCR[1], and IER[6].
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 it 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 _{Output Port 2 Channel B - The output state is defined by the user and}
through the software setting of MCR[3]. INTB is set to the active mode
and OP2B# output LOW when MCR[3] is set to HIGH. INTB is set to
the three state mode and OP2B# output HIGH when MCR[3] is set to
LOW. See MCR[3]. If INTB is used, this output should not be used as a
general output else it will disturb the INTB output functionality.
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 output
will be held HIGH, the receiver input will be ignored and outputs are
reset during reset period (see Table 15).
Pwr _{1.62V to 3.63V power supply.}
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 Connection.
Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
5