xr21b1411 Exar Corporation, xr21b1411 Datasheet - Page 3

• Manufacturer Part Number: xr21b1411
• Description: Enhanced 1-ch Full-speed Usb Uart
• Manufacturer: Exar Corporation

REV. 1.1.0
PIN DESCRIPTIONS
Pin Description
UART Signals
USB Interface Signals
Miscellaneous Signals
GPIO2/DSR#
GPIO3/DTR#
GPIO4/CTS#
GPIO5/RTS#
GPIO1/CD#
GPIO0/RI#
USBD+
USBD-
N
RX
TX
AME
16-QFN
P
10
15
14
IN
9
8
7
6
5
4
3
#
T
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
YPE
O
I
UART Receive Data. This pin has a programmable pull-up or pull-down
resistor which may be enabled by OTP programming. Resistors are not
disabled during suspend mode. Pull-up resistor will be disabled without
valid votage on VIO_REF pin.
UART Transmit Data.
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. Internal pull-
up resistor is disabled during suspend mode. This pin may also be used
by any device to signal the USB host to exit the Suspend state.
”Section 1.3.9, Remote Wakeup” on page 9.
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. Internal pull-up resistor is disabled during sus-
pend mode.
General purpose I/O or UART Data-Set-Ready input (active low).
”Section 1.3.4.2, Automatic DTR/DSR Hardware Flow Con-
trol” on page 8.
resistor which may be enabled by OTP programming. Internal pull-up
resistor is disabled during suspend mode.
General purpose I/O or UART Data-Terminal-Ready output (active low).
See ”Section 1.3.4.2, Automatic DTR/DSR Hardware Flow
Control” on page 8.
down resistor which may be enabled by OTP programming. Internal pull-
up resistor is disabled during suspend mode. This bit will be automati-
cally configured as an output when using the standard CDC-ACM driver.
General purpose I/O or UART Clear-to-Send input (active low).
”Section 1.3.4.1, Automatic RTS/CTS Hardware Flow Con-
trol” on page 7.
resistor which may be enabled by OTP programming. Internal pull-up
resistor is disabled during suspend mode.
General purpose I/O or UART Request-to-Send output (active low).
See ”Section 1.3.4.1, Automatic RTS/CTS Hardware Flow
Control” on page 7.
down resistor which may be enabled by OTP programming. Internal pull-
up resistor is disabled during suspend mode. This bit will be automati-
cally configured for hardware flow control as RTS# output when using
the standard CDC-ACM driver.
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.
USB port differential data negative input. The ESD protection on this pin
is +/-15 kV HBM.
3
This pin has a programmable pull-up or pull-down
This pin has a programmable pull-up or pull-down
ENHANCED 1-CH FULL-SPEED USB UART
This pin has a programmable pull-up or pull-
This pin has a programmable pull-up or pull-
D
ESCRIPTION
XR21B1411
See
See
See