Shift register with dual clock inputs for receiving and sending information between I/O channels and host based on external and internal clock inputs respectively

摘要

A serial interface circuits internally provided in a microcomputer and including a shift register is provided with two sets of terminals, each set including a serial data input terminal, a serial data output terminal and a clock terminal, and the two sets of terminals am alternatively used by a serial channel selection flag. Thus, a multi- channel serial interface is realized.