The XR16V25501 (V2550) is a high performance dual universal asynchronous receiver and transmitter (UART) with 16 bytes TX and RX FIFOs. The device operates from 2.25 to 3.6 volts with 5 Volt tolerant inputs and is pin-to-pin compatible to Exar's ST16C2550 and XR16C2550. The V2550 register set is compatible to the ST16C2550 and the XR16L2550. It supports Exar's enhanced features of selectable FIFO trigger level, automatic hardware (RTS/CTS) and software flow control, and a complete modem interface. Onboard registers provide the user with operational status and data error flags. An internal loopback capability allows system diagnostics. Independent programmable baud rate generators are provided in each channel to select data rates up to 16 Mbps at 3.3 Volt with 4X sampling clock. The V2550 is available in 48-pin TQFP and 32-pin QFN packages.