Exar offers the XR28V382 for the Intel Low Pin Count (LPC) bus interface
The XR28V382 (V382) is a dual Universal Asynchronous Receiver and Transmitter (UART) for the Intel Low Pin Count (LPC) bus interface. This device can replace or supplement a Super I/O device to add additional serial ports to the system. The V382 UARTs support any 16-bit I/O address supported by the system. The register set is based on the industry-standard 16550 UART, so the V382 operates with standard serial-port drivers without requiring a custom driver to be installed. The 128 Byte Transmit and Receive FIFOs reduce CPU overhead and minimize the chance of buffer overflow and data loss. In addition to the 16550 UART registers, there are also configuration register sets where enhanced features such as the 9-bit (multi-drop) mode, IrDA mode, and the Watchdog Timer can be enabled.