PURPOSE: To generate a repetitive waveform having a period of 1/n of a frequency given to each flip-flop and to attain high speed operation by connecting n-set of flip-flops in a ring and setting a required initial value of each flip-flop at reset of each flip-flop.

CONSTITUTION: n-Set of flip-flops 1-i (i=1, 2,..., n) are connected in a ring. Then a required initial value is set to each flip-flop 1-i when each flip-flop 1-i is reset. Thus, a repetitive waveform generating circuit generating a repetitive waveform of a period of 1/n of a frequency given to each flip-flop 1-i is formed. Thus, a repetitive waveform of a period of 1/n of a frequency given to each flip-flop 1-i is generated. Thus, the processing speed is quickened.