XR21V1412_10 Datasheet, PDF (5/30 Pages) Exar Corporation – 2-CH FULL-SPEED USB UART

REV. 1.1.0
Pin Description
XR21V1412
2-CH FULL-SPEED USB UART
NAME
32-QFN
PIN #
TYPE
DESCRIPTION
GPIOB1/CDB#
21
I/O _{UART Channel B general purpose I/O or UART Carrier-Detect input (active low).}
This pin has an internal pull-up resistor which is disabled during suspend mode. If
using this GPIO as an input, an external pull-up resistor is required to minimize the
power consumption in the suspend mode.
GPIOB2/DSRB# ²⁰
I/O _{UART Channel B general purpose I/O or UART Data-Set-Ready input (active low).}
See ”Section 1.5.5, Automatic DTR/DSR Hardware Flow Control” on
page 11. This pin has an internal pull-up resistor which is disabled during suspend
mode. If using this GPIO as an input, an external pull-up resistor is required to mini-
mize the power consumption in the suspend mode.
GPIOB3/DTRB# ¹⁹
I/O _{UART Channel B general purpose I/O or UART Data-Terminal-Ready output (active}
low). See ”Section 1.5.5, Automatic DTR/DSR Hardware Flow Control”
on page 11. This pin has an internal pull-up resistor which is disabled during sus-
pend mode. If using this GPIO as an input, an external pull-up resistor is required to
minimize the power consumption in the suspend mode.
GPIOB4/CTSB# ¹⁸
I/O _{UART Channel B general purpose I/O or UART Clear-to-Send input (active low).}
See ”Section 1.5.4, Automatic RTS/CTS Hardware Flow Control” on
page 10. This pin has an internal pull-up resistor which is disabled during suspend
mode. If using this GPIO as an input, an external pull-up resistor is required to mini-
mize the power consumption in the suspend mode.
GPIOB5/RTSB# ¹⁷
I/O _{UART Channel B general purpose I/O or UART Request-to-Send output (active low).}
See ”Section 1.5.4, Automatic RTS/CTS Hardware Flow Control” on
page 10. This pin has an internal pull-up resistor which is disabled during suspend
mode. If using this GPIO as an input, an external pull-up resistor is required to mini-
mize the power consumption in the suspend mode.
USB Interface Signals
USBD+
30
USBD-
29
I/O _{USB port differential data plus. This pin has a 1.5 K Ohm internal pull-up resistor.}
I/O _{USB port differential data minus.}
I2C Interface Signals
SDA
25
SCL
26
OD _I2_{C-controller data input/output (open-drain). An optional external I}2_{C EEPROM can}
be used to store default configurations upon power-up including the USB Vendor ID
and Device ID. See Table 3. A pull-up resisitor (typically 4.7 to 10 KOhms) is
required.
If an EEPROM is not used, this pin can be used with the SCL pin to select the
Remote Wake-up and Power modes. An external pull-up or pull-down resistor is
required. See Table 2.
I _I2_{C-controller serial input clock. An optional external I}2_{C EEPROM can be used to}
store default configurations upon power-up including the USB Vendor ID and Device
ID. See Table 3. A pull-up resisitor (typically 4.7 to 10 KOhms) is required.
If an EEPROM is not used, this pin can be used with the SDA pin to select the
Remote Wake-up and Power modes. An external pull-up or pull-down resistor is
required. See Table 2.
5