The XR88C92/192 is a Dual Universal Asynchronous Receiver and Transmitter with 8 (XR88C92) / 16 (XR88C192) bytes transmit and receive FIFO. The XR88C92/192 is a pin and functional replacement for the SC26C92 and an improved version of the Philips SCC2692 UART with faster data access and other additional features. The operating speed of the receiver and transmitter can be selected independently from a table of eighteen fixed baud rates, a 16X clock derived from a programmable counter/timer, or an external 1X or 16X clock. The baud rate generator and counter/timer can operate directly from a crystal or from external clock input. The XR88C92/192 provides a powerdown mode in which the oscillator is stopped but the register contents are retained. The XR88C92/192 is fabricated in an advanced CMOS process to achieve low power and high speed requirements.