PURPOSE: To realize the pulse width modulation circuit in which no exclusive logic circuit is required, the logic on an integrated circuit is decreased and large general-purpose application is attained.

CONSTITUTION: This circuit is provided with a programmable timer counter 10 and a synchronizing output circuit 30 outputting a value 200 of an output register 20 synchronously with an overflow signal 111 of the timer counter 10 and a pulse width modulation output 300 is realized as the application output of the timer counter 10. Moreover, a 1-bit output selection register controlling the synchronizing output circuit 30 is added to the configuration above, then the circuit is used for a conventional timer counter and its output terminal when no pulse width modulation output is required, the logic in the integrated circuit is minimized and general-purpose application is extended.