Frequency divider for electronic musical instrument

Abstract

A frequency divider which divides clock pulses to obtain the clock frequency of a desired dividing ratio comprises a binary counter, cycle data forming circuit and inhibit circuit to which the dividing ratio is fed in the form of the dividing ratio data. The counter counts the clock pulses, and the cycle data forming circuit converts the count value of the binary counter to a cycle data in which a certain single bit only becomes a logical state '1' and the rest of the bits are a state '0'. The bit which becomes '1' in the cycle data is uniquely determined by the count value. Further, each bit of the cycle data becomes '1' in proportion to the weight of the each bit. With the cycle data being thus formed, the dividing ratio data is simplified. The inhibit circuit receives the cycle data and the dividing ratio data to suspend the counting operation of the binary count if the bit of the dividing ratio data corresponding to the bit of the cycle data whose state is '1' is also '1'. This suspension enables the binary counter to perform a nonbinary counting operation, whereby the frequency-dividing based on the desired dividing ratio in the binary counter is implemented. By relating the diving ratio data to the pitch of a note, the frequency divider may be applicable to an electronic musical instrument.