The 82C50A Asynchronous Communication Element(ACE) is a high performance programmable UniversalAsynchronous Receiver/Transmitter (UART) and BaudRate Generator (BRG) on a single chip. Using Intersil’sadvanced Scaled SAJI IV CMOS Process, the ACE willsupport data rates from DC to 625K baud (0-10MHz clock).The ACE’s receiver circuitry converts start, data, stop, andparity bits into a parallel data word. The transmitter circuitryconverts a parallel data word into serial form and appendsthe start, parity, and stop bits. The word length isprogrammable to 5, 6, 7, or 8 data bits. Stop bit selectionprovides a choice of 1,1.5, or 2 stop bits.The Baud Rate Generator divides the clock by a divisorprogrammable from 1 to 216-1 to provide standard RS-232C baud rates when using any one of three industrystandard baud rate crystals (1.8432MHz, 2.4576MHz, or3.072MHz). A programmable buffered clock output(BAUDOUT) provides either a buffered oscillator or 16X (16times the data rate) baud rate clock for general purposesystem use.To meet the system requirements of a CPU interfacing toan asynchronous channel, the modem control signals RTS,CTS, DSR, DTR, RI, DCD are provided. Inputs and outputshave been designed with full TTL/CMOS compatibility inorder to facilitate mixed TTL/NMOS/CMOS system design.