Electronic musical instrument

Abstract

A tone production assignment circuit produces control information representing assigned key code, key-on etc. Such information has a large number of bits with respect to each channel. A multiplexing circuit has output lines the number of which is smaller than the bit number of the information and divides the information with a plurality of time slots with respect to one channel. The multiplexing circuit is controlled by a signal from a timing signal generation circuit. The multiplexing circuit is capable of rearranging information for transmitting information required for the respective individual channels and also capable of inserting a timing data in an available time slot. A multiple data analysis circuit decodes the information provided by the multiplexing circuit. Tone generators are provided for the respective channels and each one of them functions to latch only corresponding information among the decoded information by a latch circuit.

What is claimed is: 
     
       1. A keyboard electronic musical instrument having a specified number of tone production channels connected by a number of output lines, comprising: a tone production assignment circuit for assigning production of a tone selected by depression of a key to one of said channels and generating key information representing the note name of the assigned tone and key-on information representing depression or release of the key with respect to each channel to which tone production has been assigned, said key information and said key-on information for each channel together having a certain total number of bits;   data dividing means, connected to said assignment circuit and having parallel output lines of a number which is smaller than said certain total number of bits of the key information and the key-on information for each channel, for dividing the key information and the key-on information of the tone assigned to the particular channel into groups of data, each group having a number of bits matching the number of said output lines;   data multiplexing means, cooperatively connected to said data dividing means, for time division multiplexing said groups of divided data by delivering each group of data on said output lines in parallel data format, said groups being delivered sequentially in time division multiplexed order; and   a tone generator for generating the tone assigned to each channel in accordance with the multiplexed data.   
     
     
       2. An electronic musical instrument as defined in claim 1 wherein said data multiplexing means comprises means for periodically inserting data representing a reference timing in said output lines. 
     
     
       3. An electronic musical instrument as defined in claim 2 wherein said data multiplexing means further comprises means for inserting control information used commonly throughout all of the channels or used for only a specified channel in any one or more of the output lines at a suitable timing when component data of the key information or the key-on information is not provided on said one or more of the output lines. 
     
     
       4. An electronic musical instrument as defined in claim 1 wherein said data dividing means comprises: first through N-th selection means for dividing said total number of bits of the key information and the key-on information into N groups (where N represents an integer of 2 or a larger number) with respect to each of the channels and for sequentially selecting each of the divided groups of data with a time delay; and wherein said data multiplexing means comprises:   gating means for selecting one or more control information used commonly throughout all of the channels or for only a specified channel at a predetermined timing;   OR gate groups having a specified number of parallel output lines for combining the outputs of said first through N-th selection means and said gating means;   control means for generating first through N-th pulses sequentially and repeatedly with a delay of a predetermined time period for controlling the timing of sequential selection by said first through N-th selection means;   timing pulse generation means for generating a timing pulse which controls the timing of selection by said gating means; and   reference data insertion means for inputting a control pulse generated at a certain reference time within each repetitive cycle in which information of all of the channels is multiplexed, and for supplying a unique group of data representing the reference timing to said OR gate groups in response to said input control pulse.   
     
     
       5. An electronic musical instrument as defined in claim 4 which further comprises multiplexed data distribution means which receives the multiplexed data provided by said data multiplexing means through said output lines and distributes each of the multiplexed data to each of separate tone generators in accordance with the channel of the multiplexed data. 
     
     
       6. An electrical musical instrument as defined in claim 5 wherein said multiplexed data distribution means comprises: means for detecting the data representing the reference timing from among the multiplexed data supplied by said data multiplexing means for generating a reference pulse in response to the detection;   shift means for successively shifting the reference pulse; and   latch means for successively latching the multiplexed data provided by said data multiplexing means in accordance with the reference pulse successively shifted in said shift means thereby to distribute the key information and the key-on information contained in the multiplexed data to the respective channels. .Iadd. 7. A polyphonic keyboard electronic musical instrument having a specified number of tone production channels, comprising:   key information generating means for generating key information relating to depressed ones among keys in a keyboard,   channel assignment means for assigning said key informations to available ones of the specified number of tone production channels,   multiplexing means for time division multiplexing said assigned key informations by delivering each key information in parallel data format, said key informations being delivered sequentially in time division multiplexed order;   tone generating means having the same number of tone generators as said specified number of tone production channels, each of said tone generators corresponding to a respective one of said tone production channels, and   demultiplexing means connected between said multiplexing means and said tone generating means for demultiplexing said delivered key informations and for supplying each demultiplexed key information to the tone generator corresponding to the tone production channel to which said delivered key information is assigned, so that said tone generators respectively generate tone signals in accordance with the respective supplied key information. .Iaddend. .Iadd. 8. A polyphonic electronic musical instrument comprising:   keyboard means having a plurality of keys,   key information generating means for generating key information relating to depressed ones among said keys,   channel assignment means for assigning said key information to available ones of a specified number of tone production channels,   envelope information generating means for generating envelope information serving to determine an envelope characteristic of a tone, said envelope information being used commonly throughout all of said tone production channels,   multiplexing means connected to said channel assignment means and said envelope information generating means for transmitting said key information and said envelope information over output lines using a predetermined number of time slots, each of said key information being allotted to a predetermined time slot in accordance with the assigned tone production channel of the key information and the envelope information being allotted to a predetermined time slot on one or more of said output lines in which said key information is not provided,   tone generating means having tone generators each of which corresponds to a respective one of the tone production channels,   envelope imparting means having envelope imparting circuits each of which is connected to a respective one of said tone generators; and   demultiplexing means connected to said output lines for supplying said transmitted key information to the tone generators corresponding to said tone production channels to which said transmitted key information is assigned respectively and for supplying said transmitted envelope information to all of said envelope imparting circuits, said tone generators generating tone signals in accordance with said supplied key information respectively and said envelope imparting circuits imparting the envelope characteristic to the corresponding tone signals. .Iaddend. .Iadd. 9. In a keyboard polyphonic electronic musical instrument of the type having plural tone generator channels, the number of such channels being considerably fewer than the total number of keys, the improvement comprising:   memory means storing a channel assignment table containing for each assigned channel a key code and associated key depression state data for the selected key which is assigned to that channel,   data transmission lines,   time division multiplex means for repetitively, consecutively transmitting the contained key codes and associated key depression state data via said data transmission lines during corresponding intervals in each time division multiplex cycle, and   demultiplexer means, connected to said data transmission lines and receiving said time division multiplex key codes and data, for demultiplexing the same and supplying to each tone generator channel only the demultiplexed key code and associated key depression state data for the selected key assigned to that channel. .Iaddend. .Iadd. 10. An electronic musical instrument according to claim 9 further comprising:   envelope information generating means for producing envelope ascertaining information for common usage by all of said tone generator channels,   said multiplexer means including circuitry for transmitting said envelope ascertaining information from said envelope information generating means onto said data transmission lines as part of each time division multiplex cycle, and   an envelope imparting circuit in each tone generator channel, each envelope imparting circuit utilizing said transmitted common envelope ascertaining information and the key depression state data for the corresponding channel to impart the requisite envelope to the tone generated in that channel. .Iaddend..Iadd. 11. An electronic musical instrument according to claim 10 wherein said multiplexer means gates said envelope ascertaining information onto said data transmission lines at the beginning of each time division multiplex cycle. .Iaddend. .Iadd. 12. A keyboard electronic musical instrument having a specified number of tone production channels connected by a number of output lines, comprising:   a tone production assignment circuit for assigning production of a tone selected by depression of a key to one of said channels and generating key information representing the note name of the assigned tone and key-on information representing depression or release of the key with respect to each channel to which tone production has been assigned, said key information and said key-on information for each channel together having a certain total number of bits;   a number of parallel output transmission lines;   data multiplexing means for time division multiplexing said key information and key-on information by delivering the same on said output transmission lines in parallel data format, said information being delivered sequentially in time division multiplexed order,   a tone generator for generating the tone assigned to each channel in accordance with the multiplexed information, and   means for inserting envelope control information used commonly throughout all of the channels or used for only a specified channel in any one or more of the output transmission lines at a suitable timing when component data of the key information or the key-on information is not provided on said one or more of the output transmission lines. .Iaddend. .Iadd. 13. In a keyboard electronic musical instrument of the type having a small number of tone generator channels, for which channels key code and key depression state data are supplied in time division multiplex format, the improvement comprising:   assignment memory means containing a channel assignment table in which there is a data entry position for each tone generator channel,   first means for ascertaining by comparison with prior entered data in said table whether a key code for a selected key is already entered in said table and if not, for entering the key code and associated key depression state data for that selected key into an available data entry position of said table,   second means for reading out all of the entered key codes and associated key depression state data from said channel assignment table in a certain order and in certain delivery time zones for time division multiplex transmission to said tone generator channels, and   timing control means, cooperatively connected to said first and second means, for establishing a timing and order for key code and data entry into said table by said first means, and for establishing a different timing and order for readout and transmission of key codes and data from said table by said second means. .Iaddend.