Time-shared scanning keyboard interface.

摘要

A time shared scanning keyboard interface comprises a timing generator 11 which generates a detecting signal for an interface circuit 12, and a control signal for a register 13 and an encoder 14. The interface circuit 12 is connected to an external keyboard, and receives a detecting signal from a timing generator which it uses to scan keyboard interface parts. The detected status of the interface ports is transmitted then to the register 13. The register 13 transmits the status of the ports to an encoder 14. <IMAGE>