D2XX is Future Technology Devices International (FTDI) proprietary interface for easy communication with its FTxxxx devices like FT232R (USB<->UART converter) or FT4222H (High/Full Speed USB2.0-to-Quad SPI/I2C device controller). The D2XX interface provides special functions that are not available in standard operating system COM port APIs, such as setting the device into a different mode or writing data into the device EEPROM.
