General keyboard interface for operating with two types of keyboards

摘要

A keyboard interface is implemented in an integrated circuit and supports first and second types of keyboards and associated interfaces from a single set of integrated circuit terminals. The keyboard interface includes a first keyboard logic responsive to a first mode select signal for providing a first set of control signals for supporting the first type of keyboard and second keyboard logic responsive to a second mode select signal for providing a second set of control signals for supporting the second type of keyboard. A multiplexer couples the first set of control signals to the set of terminals responsive to the first mode select signal and couples the second set of control signals to the set of terminals responsive to the second mode select signal. A keyboard register provides the first or second mode select signals to the first and second keyboard logic and the multiplexer.