Usb-To-Uart Bridge - Xilinx VC709 User Manual

VC709 Evaluation Board Features
Chapter 1:

USB-to-UART Bridge

[Figure
The VC709 board contains a Silicon Labs CP2103GM USB-to-UART bridge device (U44) which
allows a connection to a host computer with a USB port. The USB cable is supplied in the VC709
evaluation kit (type-A end to host computer, type mini-B end to VC709 board connector J17). The
CP2103GM is powered by the USB 5V provided by the host PC when the USB cable is plugged into
the USB port on the VC709 board.
Xilinx UART IP is expected to be implemented in the FPGA fabric. The FPGA supports the
USB-to-UART bridge using four signal pins: Transmit (TX), Receive (RX), Request to Send (RTS),
and Clear to Send (CTS).
Silicon Labs provides royalty-free Virtual COM Port (VCP) drivers for the host computer. These
drivers permit the CP2103GM USB-to-UART bridge to appear as a COM port to communications
application software (for example, TeraTerm or HyperTerm) that runs on the host computer. The
VCP device drivers must be installed on the host PC prior to establishing communications with the
VC709 board.
The USB Connector pin assignments and signal definitions between J17 and U44 are listed in
Table
Table 1-15: USB Connector J17 Pin Assignments and Signal Definitions
USB Connector (J17)
Pin Name
1 VBUS USB_UART_VBUS
2 D_N USB_D_N
3 D_P USB_D_P
4 GND USB_UART_GND
Table 1-16
Table 1-16: FPGA to UART Connections
FPGA (U1)
Pin Function
AR34 RTS
AT32 CTS
AU36 TX
AU33 RX
Refer to the
46
Send Feedback
1-2, callout 13]
1-15.
Net Name
+5V VBUS powered
Bidirectional differential serial data (N-side)
Bidirectional differential serial data (P-side)
Signal ground
shows the USB connections between the FPGA and the UART.
Direction I/O Standard
Output LVCMOS18
Input LVCMOS18
Output LVCMOS18
Input LVCMOS18
website for technical information on the CP2103GM and the VCP drivers.
Silicon Labs
www.xilinx.com
Description
Schematic
Net Name
Pin
USB_UART_CTS 22
USB_UART_RTS 23
USB_UART_RX 24
USB_UART_TX 25
CP2103GM (U44)
Pin Name
7 REGIN
8 VBUS
4 D –
3 D +
2 GND1
29 CNR_GND
CP2103GM UART (U44)
Function Direction
CTS Input
RTS Output
RXD Input
TXD Output
VC709 Evaluation Board
UG887 (v1.6) March 11, 2019