The Universal Asynchronous Receiver/Transmitter (UAR/T) is an LSI subsystem that accepts binary characters from either a terminal device or a computer and receivers/transmits this character with appended control and error-detecting bits. All characters contain a start bit, 5 to 8 data bits, 1, 1-1/2, or 2 stop bit capability, and either odd/even parity or no parity. To make the UAR/T universal, the baud, bits per word, parity mode, and the number of stop bits are externally delectable. The device is on a single monolithic chip. All inputs and outputs are directly compatible with TTL/DTL/CMOS logic without the need for interfacing components. All strobed outputs are three-state logic.