High note data generator

An electronic musical instrument comprising:

• a keyboard having a plurality of playing keys,
• clock means for generating a train of clock pulses,
• multiplexer means clocked by said clock means for scanning said keyboard and generating a cyclically recurring time division multiplexed first serial data stream comprising a plurality of time slots corresponding to the keys of the keyboard,
• a preferential note data generator means clocked by said clock means and having an input and an output, said preferential note data generator means generating a cyclically recurring second serial data stream on its output comprising a plurality of time slots synchronized with and temporally coextensive with the time slots of said first mentioned data stream,
• said preferential note data generator means being responsive to the leading edge of a first pulse on its input to generate a second pulse in a time slot of said second data stream coinciding with the leading edge of said first pulse and having a duration independent of the duration of said first pulse, said second pulse being completely contained within said time slot coinciding with the leading edge of said first pulse.

An electronic musical instrument comprising:

• a keyboard having a plurality of playing keys,
• clock means for generating a train of clock pulses,
• multiplexer means clocked by said clock means for scanning said keyboard and generating a cyclically recurring time division multiplexed serial data stream comprising a plurality of time slots corresponding to the keys of the keyboard and a series of serial keydown pulses in respective time slots pertaining to depressed keys of the keyboard,
• a first latch means having an input connected to said serial data stream for initiating a pulse on an output of said latch means when the leading edge of said keydown pulse in the serial data stream appears on its input and for generating a control signal,
• AND function gate means generating an output signal on its output when said control signal and a predetermined polarity of said clock pulse train are on its respective inputs, and
• a second latch means having an input connected to said AND function gate means output and an output connected to a control input of said first latch means, said second latch means generating a control signal on its output in response to said output signal from said AND function gate means to cause said first latch means to change state thereby terminating the pulse on the output of said first latch means.

In an electronic musical instrument having a keyboard including a plurality of playing keys, clock means for generating a train of clock pulses, and multiplexer means clocked by said clock means for scanning said keyboard and producing on a serial data line a cyclically recurring time division multiplexed serial data stream comprising a plurality of time slots corresponding to the keys of the keyboard and a series of keydown pulses in respective time slots pertaining to depressed keys of the keyboard, said multiplexer means generating a latch command signal on a latch command line at the end of each scan of the keyboard, a preferential note data generator for producing on an output terminal a single pulse in a time slot corresponding to the time slot of the first occurring keydown pulse in said data stream, said data generator comprising:

• a first latch having a data input at a first binary logic level, one of a set and reset input at said first binary logic level, an output means connected to said output terminal, and a clocking input connected to said serial data line,
• a second latch having a data input connected to said serial data line, one of a set and reset input connected to said latch command line, an output connected to said one of a set and reset input of said first latch, and a clocking input, and
• an AND function gate having a first input connected to said first latch output means, a second input connected to said clock means, and an output connected to the clocking input of said second latch.