XR21B1411IL-0A-EB Datasheet, PDF (3/30 Pages) Exar Corporation – ENHANCED 1-CH FULL-SPEED USB UART

REV. 1.2.0
PIN DESCRIPTIONS
Pin Description
NAME
UART Signals
RX
16-QFN
PIN #
10
TX
9
GPIO0/RI#/RWK#
8
GPIO1/CD#
7
GPIO2/DSR#
6
GPIO3/DTR#
5
GPIO4/CTS#
4
GPIO5/RTS#/RS485
3
USB Interface Signals
USBD+
15
USBD-
14
XR21B1411
ENHANCED 1-CH FULL-SPEED USB UART
TYPE
DESCRIPTION
I
UART Receive Data. This pin has a programmable pull-up or pull-down
resistor which may be enabled by OTP programming. Pull-up resistor
will be disabled without valid voltage on VIO_REF pin.
O
UART Transmit Data.
I/O _{General purpose I/O or UART Ring-Indicator input (active low) or}
Remote Wakeup input. This pin has a programmable pull-up or pull-
down resistor which may be enabled by OTP programming. This pin
may also be used by any device to signal the USB host to exit the Sus-
pend state. See ”Section 1.3.10, USB Suspend” on page 9.
I/O _{General purpose I/O or UART Carrier-Detect input (active low). This pin}
has a programmable pull-up or pull-down resistor which may be enabled
by OTP programming.
I/O _{General purpose I/O or UART Data-Set-Ready input (active low). See}
”Section 1.3.5.2, Automatic DTR/DSR Hardware Flow Con-
trol” on page 8. This pin has a programmable pull-up or pull-down
resistor which may be enabled by OTP programming.
I/O _{General purpose I/O or UART Data-Terminal-Ready output (active low).}
See ”Section 1.3.5.2, Automatic DTR/DSR Hardware Flow
Control” on page 8. This pin has a programmable pull-up or pull-
down resistor which may be enabled by OTP programming. This bit will
be automatically configured as an output when using the standard CDC-
ACM driver.
I/O _{General purpose I/O or UART Clear-to-Send input (active low). See}
”Section 1.3.5.1, Automatic RTS/CTS Hardware Flow Con-
trol” on page 8. This pin has a programmable pull-up or pull-down
resistor which may be enabled by OTP programming.
I/O _{General purpose I/O or UART Request-to-Send output (active low) or}
auto RS-485 half-duplex control. See “Section 1.3.5.1, Automatic
RTS/CTS Hardware Flow Control” on page 8 or “Section
1.3.6, Auto RS-485 Half-Duplex Control” on page 8. This pin
has a programmable pull-up or pull-down resistor which may be enabled
by OTP programming. This bit will be automatically configured for hard-
ware flow control as RTS# output when using the standard CDC-ACM
driver.
I/O _{USB port differential data positive input. This pin has internal pull-up}
resistor compliant to USB 2.0 specification. The ESD protection on this
pin is +/-15 kV HBM.
I/O _{USB port differential data negative input. The ESD protection on this pin}
is +/-15 kV HBM.
3