Dual Asynchronous Receiver / Transmitter
The MC68681 dual universal asynchronous receiver/transmitter (DUART) is part of the M68000 Family of peripherals and directly interfaces to the MC68000 processor via an asynchronous bus structure. The MC68681 consists of eight major sectors: internal control logic, timing logic, interrupt control logic, a bidirectional 8-bit data bus buffer, two independent communication channels (A and B), a 6-bit parallel input port, and an 8-bit parallel output port.