The XR16C850*1 (850) is a universal asynchronous receiver and transmitter (UART) and is pin compatible with the ST16C550,ST16C650A, and TI's TL16C750 UART. The 850 is an enhanced UART with 128 byte FIFOs, automatic hardware/software flow control, and data rates up to 1.5Mbps. It includes transmit/receive FIFO counters to increase data loading and unloading throughput. Onboard status registers provide error indications and operational status. Modem interface control is included and can be optionally configured to operate with the Infrared (IrDA) encoder/decoder. Internal loopback allows onboard diagnostics. The 850 is available in 40-pin PDIP, 44-pin PLCC, 48-pin TQFP, and 52-pin QFP packages. The 44, 48, and 52 pin versions provide both the standard (STD) mode or PC mode. The STD mode is compatible with the ST16C450, ST16C550, ST16C650A and TL16C750 while the PC mode supports standard PC COM port connections. The 40 PDIP pin package does not offer the PC mode.