To provide an operation mode generation circuit for generating a mode signal for selecting some one operation mode from among a plurality of operation modes based on the frequency of a mode selection signal inputted from one external terminal.

This circuit includes a mode determination circuit 2 for generating a plurality of mode determination signals A-C changing stepwise corresponding to the frequency of the mode selection signal MS based on input of the mode selection signal MS having a different frequency, and a decoder circuit 3 for generating mode signals TM1-TM3 from the mode determination signals A-C.