The one, two and four channel USB UARTs are compliant to USB 2.0 specification and can operate up to 12 Mbps full speed. All packages have been optimized. The single channel XR21V1410 device is offered in a 16-pin QFN package, the two channel XR21V1412 UART in a 32-pin QFN, and the four channel XR21V1414 UART in a 48-pin TQFP package. Any UART channel can operate at data rates of up to 12 Mbps. Using the software driver, the modem control signals can be programmed as GPIOs or vice-versa. In addition, MaxLinear's standard UART products offer several enhanced features including the Fractional Baud Rate Generator, Automatic Transceiver Enable, and Multidrop Modes. Software drivers for several operating systems such as Windows, Linux, and MAC are available for these USB UARTs. MaxLinear also offers WHQL certified drivers and provides source code for these drivers.