SINGLE CHIP MICROCOMPUTER

摘要

PROBLEM TO BE SOLVED: To prevent malfunction in a single chip microcomputer having an external synchronizing signal. SOLUTION: The external synchronizing signal E formed in an internal clock generation circuit 11 is outputted to an external terminal 275 through a gate means 12. A control signal C corresponding to a setting state is supplied to the control terminal of the gate means 12 from a control register 15 to which data can be set by a microprocessor, and the external synchronizing signal E is controlled to be not outputted to the external terminal 23. Thus, the output of the external synchronizing signal E to the external terminal (pin) can be inhibited in a single chip mode.