The Intel CHMOS 82510 is designed to increase system efficiency in asynchronous environments such as modems or serial ports - including expanding performance areas: MCS-51 9-bit format and high speed async. The functional support provided in the 82510 is unparalleled - two baud rate generators/timers provide independent data rates or protocol timeouts; a crystal oscillator and smart modem I/O simplify system logic. New features - dual FIFOs and Control Character Recognition (CCR) - dramatically reduce CPU interrupts and increase software efficiency. All interrupts are maskable at two levels and the multipersonality I/O pins are configurable as desired.