XR16L2752 Datasheet, PDF (5/49 Pages) Exar Corporation – 2.25V TO 5.5V DUART WITH 64-BYTE FIFO

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REV. 1.2.1
Pin Description
NAME
CTSB#
44-PLCC
PIN #
28
DTRB#
27
DSRB#
29
CDB#
30
RIB#
31
MFB#
19
XR16L2752
2.25V TO 5.5V DUART WITH 64-BYTE FIFO
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#, BAUD-
OUTB#, 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 sig-
nal 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 16X Baud rate clock
output is available at this pin.
ANCILLARY SIGNALS
XTAL1
11
XTAL2
13
RESET
21
VCC
GND
44, 33
22, 12
3) RXRDYB# - RXRDYB# (active low) is intended for monitoring DMA data transfers.
See Table 2 for more details.
I Crystal or external clock input. Caution: this input is not 5V tolerant.
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 External Reset
Conditions).
Pwr 2.25 to 5.5V power supply. All input pins, except XTAL1, are 5V tolerant.
Pwr Power supply common, ground.
Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
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