WARP v3 User Guide: USB UART

The WARP v3 board includes a USB UART transceiver to ease interaction with embedded processors running in the FPGA. The transceiver is the FTDI FT230X. For the full specs refer to the ​FT230X datasheet.

User designs must implement a UART in the FPGA to interface with the FT230X. Designs built in XPS can use the xps_uartlite pcore to implement STDIN/STDOUT for MicroBlaze designs. The FT230X supports all baud rates implemented by xps_uartlite. Ensure your terminal emulator configures the virtual COM port for the same baud rate specified in the xps_uartlite instance.

The USB UART transceiver is connected to two FPGA pins, listed in the UCF snippet below.

#USB UART
Net fpga_0_UART_USB_TX_pin LOC = H9 | IOSTANDARD=LVCMOS25; #FT230X RXD pin
Net fpga_0_UART_USB_RX_pin LOC = J9 | IOSTANDARD=LVCMOS25; #FT230X TXD pin

Using the UART on a PC

Accessing the USB UART interface from a PC requires installation of the FTDI Virtual COM Port (VCP) driver. This driver is maintained by FTDI and is available free on their ​web site. We have successfully tested the USB UART using the FTDI drivers under Windows 7 and OS X. Any platform supported by FTDI should also work.

Once the drivers are installed your PC will recognize a new COM port when you connect a micro USB cable to the WARP v3 board. Refer to the USB UART howto for instructions on managing the COM port and recommendations on terminal emulators.