XR19L222 Datasheet, PDF (4/53 Pages) Exar Corporation – TWO CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER

XR19L222
TWO CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
Pin Descriptions
REV. 1.0.0
NAME
64-QFN
PIN#
TYPE
DESCRIPTION
MODEM OR SERIAL I/O INTERFACE (EIA-232/RS-232 Voltage Levels)
TXDA
44
O _{UART Channel A Transmit Data. The TX signal will be LOW (< 1.5V) during reset or idle (no}
data).
RXDA
36
I _{UART Channel A Receive Data. The RX data input must idle LOW (< 1.5V). This input has}
an internal pull-down resistor and can be left unconnected when not used.
RTSA
31
O _{UART Channel A Request-to-Send or general purpose outputs. These outputs must be}
asserted prior to using auto RTS flow control, see EFR[6], MCR[1] and IER[6].
CTSA
1
I _{UART Channel A Clear-to-Send or general purpose inputs. It can be used for auto CTS}
flow control, see EFR[7], MSR[4] and IER[7]. This input has an internal pull-down resistor
and can be left unconnected when not used.
DTRA
41
O _{UART Channel A Data-Terminal-Ready or general purpose outputs.}
DSRA
40
I _{UART Channel A Data-Set-Ready or general purpose inputs. This input has an internal pull-}
down resistor and can be left unconnected when not used.
CDA
61
I _{UART Channel A Carrier-Detect or general purpose inputs. This input has an internal pull-}
down resistor and can be left unconnected when not used.
RIA
60
I _{UART Channel A Ring-Indicator or general purpose inputs. This input has an internal pull-}
down resistor and can be left unconnected when not used.
TXDB
29
O _{UART Channel B Transmit Data. The TX signal will be LOW (< 1.5V) during reset or idle (no}
data).
RXDB
32
I _{UART Channel B Receive Data. RXDB will be the input signal to the internal UART when}
RXBSEL is LOW. If RXB is used, then RXBSEL should be HIGH. The RX data input must
idle LOW (< 1.5V). This input has an internal pull-down resistor and can be left uncon-
nected when not used.
RTSB
4
O _{UART Channel B Request-to-Send or general purpose outputs. These outputs must be}
asserted prior to using auto RTS flow control, see EFR[6], MCR[1] and IER[6].
CTSB
3
I _{UARTChannel B Clear-to-Send or general purpose inputs. It can be used for auto CTS}
flow control, see EFR[7], MSR[4] and IER[7]. This input has an internal pull-down resistor
and can be left unconnected when not used.
DTRB
13
O _{UART Channel B Data-Terminal-Ready or general purpose outputs.}
DSRB
16
I _{UART Channel B Data-Set-Ready or general purpose inputs. This input has an internal pull-}
down resistor and can be left unconnected when not used.
CDB
62
I _{UART Channel B Carrier-Detect or general purpose inputs. This input has an internal pull-}
down resistor and can be left unconnected when not used.
RIB
15
I _{UART Channel B Ring-Indicator or general purpose inputs. This input has an internal pull-}
down resistor and can be left unconnected when not used.
SERIAL I/O INTERFACE (CMOS/TTL Voltage Levels)
TXB
10
O _{UART Channel B Transmit data. This is the TXB output signal from the UART. This pin can}
be used to communicate with an external Infrared or RS-422 transceiver if TXDB is unused.
RXB
9
I _{UART Channel B Receive data. This is the RXB input signal to the UART. If RXDB is not}
used (RXBSEL is HIGH), then this pin can be used to communicate with an external Infra-
red or RS-422 transceiver. If RXDB is used (RXBSEL is LOW), this pin should be left open.
4