The XR16M752/XR68M7521 (M752) is a high performance dual universal asynchronous receiver and transmitter (UART) with 64 byte TX and RX FIFOs. The M752 operates from 1.62 to 3.63 volts. It is pin-to-pin and software compatible to the TL16C752B and SC16C752B, but with additional features such as a programmable fractional baud rate generator, automatic RS-485 half-duplex direction control, infrared mode and 8X and 4X sampling rate. The standard features include 16 selectable TX and RX FIFO trigger levels, automatic hardware (RTS/ CTS) and software (Xon/Xoff) 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. Each channel is independently programmable for data rates up to 16 Mbps at 3.3V with a 4X sampling rate. The XR68M752 has an additional 16/68# pin to select between the Intel and Motorola bus interface. The M752 is available in the 48-pin TQFP, 32-pin QFN and 49-pin STBGA packages.