XR16L2552IM-F Datasheet, PDF (4/45 Pages) Exar Corporation – 2.25V TO 5.5V DUART WITH 16-BYTE FIFO

XR16L2552
2.25V TO 5.5V DUART WITH 16-BYTE FIFO
Pin Description
REV. 1.1.2
NAME
48-TQFP
PIN#
44-PLCC
PIN #
TYPE
DESCRIPTION
RXRDYB#
8
-
O UART channel B Receiver Ready (active low). This output provides the RX
FIFO/RHR status for receive channel B. This pin is only available on the 48-
pin TQFP package. If it is not used, leave it unconnected.
MODEM OR SERIAL I/O INTERFACE
TXA
35
38
O UART channel A Transmit Data. If it is not used, leave it unconnected.
RXA
36
39
I UART channel A Receive Data. Normal receive data input must idle at logic 1
condition. If it is not used, tie it to VCC or pull it high via a 100k ohm resistor.
RTSA#
33
36
O UART channel A Request-to-Send (active low) or general purpose output.
This output must be asserted prior to using auto RTS flow control, see EFR[6],
MCR[1] and IER[6]. If it is not used, leave it unconnected.
CTSA#
38
40
I UART channel A 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.
DTRA#
34
37
O UART channel A Data-Terminal-Ready (active low) or general purpose output.
If it is not used, leave it unconnected.
DSRA#
39
41
I UART channel A 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.
CDA#
40
42
I UART channel A 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.
RIA#
41
43
I UART channel A 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.
TXB
22
26
O UART channel B Transmit Data. If it is not used, leave it unconnected.
RXB
21
25
I UART channel B Receive Data. Normal receive data input must idle at logic 1
condition. If it is not used, tie it to VCC or pull it high via a 100k ohm resistor.
RTSB#
18
23
O UART channel B Request-to-Send (active low) or general purpose output.
This output must be asserted prior to using auto RTS flow control, see EFR[6],
MCR[1] and IER[6]. If it is not used, leave it unconnected.
CTSB#
24
28
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.
DTRB#
23
27
O UART channel B Data-Terminal-Ready (active low) or general purpose output.
If it is not used, leave it unconnected.
DSRB#
25
29
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.
CDB#
26
30
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.
4