Keyboard and controller with a three wire half duplex asynchronous and bidirectional communications architecture

摘要

A controller and communications architecture for controlling the operation of computer I/O devices such as a keyboard or the like includes two microprocessors, a three-wire half duplex communications interface and a transmission protocol allow data transmission, error, detection and contention resolution. The transmission protocol allows the microprocessors to transmit serial data over the interface which includes a single shared data line and two simplex clock lines.