Electronic musical instrument

An electronic musical instrument comprising key switches, a key code register coupled to said key switches for providing coded data in response to key switch depression, a note frequency data memory for storing note frequency data corresponding to the coded data from the key code register;

• a time division control signal generator for generating a time division pulse;
• a note frequency data register for latching and storing the data from the note frequency data memory by the time division pulse from the time division control signal generator;
• an octave data register for latching and storing octave data from the key code register by the time division pulse from the time division control signal generator;
• a frequency generator composed of a programmable counter receiving the output from the note frequency data register to provide a generator frequency corresponding thereto, a frequency divider array having a plurality of output ends and supplied with said generator frequency, and a decoder supplied with the output from the octave data register, the outputs from the respective output ends of the frequency divider array being selected by the output from the decoder in accordance with the octave data to produce a frequency generator output;
• a musical waveform generator composed of wave generator circuits and supplied with the output from the frequency generator to provide an analog signal;
• and
• a phase lock loop circuit inserted between the programmable counter and the frequency divider array for multiplying said generator frequency a predetermined amount, a selector circuit in said note frequency data register responsive to an address assignment part of the coded data from the key code register for supplying the note frequency data from the note frequency data memory or a separate fixed note frequency data to the programmable counter depending upon the presence of absence of the address assignment, thereby to improve the lock-up time of the phase lock loop circuit when the address assignment part of the coded data changes.

An electronic musical instrument comprising:

• key switches, a key code register coupled to said key switches for providing coded data in response to key switch depression,
• a note frequency data memory for storing note frequency data corresponding to the coded data from the key code register;
• a time division control pulse generator for generating a time division pulse,
• a note frequency data register for latching and storing the data from the note frequency memory by the time division pulse from the time division control signal generator;
• an octave data register for latching and storing octave data from the key code register by the time division pulse from the time division control signal generator;
• a frequency generator composed of a programmable counter supplied with the output from the note frequency data register to provide a generator frequency corresponding thereto, a frequency divider array having a plurality of output ends and supplied with said generator frequency, and a decoder supplied with the output from the octave data register, the outputs from the respective output ends of the frequency divider array being selected by the output from the decoder in accordance with the octave data to provide a frequency generator output;
• a musical waveform generator composed of wave generating circuits corresponding to respective musical instrument sounds and supplied with the output from the frequency generator to provide an analog signal;
• a vibrato oscillator, and
• a vibrato generator comprising an up-down counter supplied with the output from the vibrato oscillator and producing an output f, the up-down counter further providing the outputs 2f and 4f, dividing means for dividing the output frequency data from the note frequency data memory into a plurality of groups of adjoining notes, adder means for taking one or more of the outputs f, 2f and 4f and adding it to or subtracting it from the output from the note frequency data memory to produce a vibrato effect to the note frequency data, the note frequency data with the vibrato effect being applied to the programmable counter of the frequency generator by means of the note frequency data register.