The XR16C8721 (872) is a dual universal asynchronous receiver and transmitter (UART) with a 1284 bi-directional parallel port and ISA Bus Plug-and-Play (PnP) interface. The PnP interface supports auto configuration for desktop and embedded PC computers. The host bus interface can also be configured to manually support standard PC addresses COM1-4 and LPT1-2. The parallel port is compatible to IEEE 1284 specification and supports Compatible Centronics, Extended Capability (ECP) and Enhanced Parallel Port (EPP) protocols. The UARTs are software compatible to industry standard 16C550 and include enhanced features of 128 bytes of transmit and receive FIFOs, programmable transmit and receive FIFO trigger levels, transmit and receive FIFO counters, IrDA (Infrared