The XR16L27511 (2751) is a low voltage dual universal asynchronous receiver and transmitter (UART) with 5 Volt tolerant inputs. The device includes 2 additional capabilities over the XR16L2750: Intel and Motorola data bus selection and a "PowerSave" mode to further reduce sleep current to a minimum during sleep mode. The 2751's register set is compatible to the ST16C2550 and XR16C2850 but with added functions. It supports the Exar's enhanced features of 64 bytes of TX and RX FIFOs, programmable FIFO trigger level, FIFO level counters, automatic hardware and software flow control, automatic RS-485 half duplex direction control with programmable turn-around delay, and a complete modem interface. Onboard registers provide the user with operational status and data error tags. An internal loopback capability allows onboard diagnostics. Independent programmable baud rate generator is provided in each UART channel to support data rates up to 6.25 Mbps.