JPH06161454A - Waveform storing and reproducing device - Google Patents

Abstract

PURPOSE:To efficiently utilize a waveform memory in the waveform storing and reproducing device. CONSTITUTION:While a sound signal inputted from an input terminal 30 is converted by an A/D converting circuit 54 into waveform data TWD, the level of the input sound signal is detected by a level detecting circuit 40 and an address counter 16A is put in operation according to its detection signal to write the waveform data TWD in a storage area M1 of the waveform memory 10. The detecting circuit 40 detects the level of the input sound signal decreasing below a specific value after the waveform data begins to be written and the operation of the counter 16A is stopped according to the detection signal to stop the writing. A delay circuit 56 slightly delays the writing stop timing and the attenuation part of the sound waveform can securely be stored. Sound waveforms can be stored in storage areas M2, M3... similarly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform storing / reproducing apparatus for inputting a desired sound signal and storing the waveform data in a waveform memory, and more particularly to detecting that the input sound signal is attenuated to a predetermined level. Then, the write operation is stopped to enable efficient use of the waveform memory.

[0002]

2. Description of the Related Art Conventionally, as a sound signal input type waveform storage / reproduction device, there has been known a device which starts writing operation upon detecting that an input sound signal has reached a predetermined level (for example, for example). , JP-A-55-166698). In this conventional device, the maximum address of the waveform memory is detected and the write operation is stopped.

[0003]

According to the above-mentioned conventional technique, the waveform memory can store only one sound waveform data, resulting in low utilization efficiency.

In order to store the waveform data for a plurality of tones in the waveform memory, a method of stopping the writing operation of the first tone by, for example, operating a switch can be considered. However, with this method, it is difficult to perform the switch operation in synchronization with the timing at which the sound naturally decays, and the switch operation is too fast to store the sound wave attenuation part sufficiently or the switch operation is too late. Some storage space is wasted (not used)
There is a drawback that becomes.

An object of the present invention is to provide a novel waveform storage / reproduction device which can improve the utilization efficiency of the waveform memory.

[0006]

A waveform storage / reproduction device according to the present invention stores an input means for inputting a sound signal, a readable / writable waveform storage means, and a waveform of a sound signal input from the input means. Writing means for writing the waveform data to the waveform storing means, and detecting that the level of the sound signal input from the input means has dropped to a predetermined value or less after the writing of the waveform data is detected, and outputs a detection signal. Generated detecting means, stop control means for controlling the writing means to stop writing of the waveform data based on the detection signal from the detecting means, and waveform data is read from the waveform storing means to generate a sound signal. And a reproducing means for reproducing.

[0007]

According to the structure of the present invention, the writing of the waveform data is stopped by detecting that the level of the input sound signal has dropped below a predetermined value, so that the storage area after the writing stop position is stored. Waveform data of other sound signals can be stored. Further, since the writing is automatically stopped, the unused area in the waveform memory can be minimized, and since the sound wave-shaped attenuating portion can be surely stored, faithful reproduction is possible.

In the structure of the present invention, the writing of the waveform data may be stopped in accordance with the signal obtained by delaying the detection signal from the detection means by a predetermined time. By doing so, for example, the waveform data of the attenuating portion can be sufficiently stored for the musical tone waveform that attenuates slowly, and more faithful reproduction can be performed.

[0009]

1 shows a circuit configuration of an autorhythm device according to an embodiment of the present invention. The autorhythm device includes a rhythm tone generator section RTG having 12 time-divisional tone generation channels. ing. That is, in the rhythm sound source section RTG, a first waveform memory 10 including a RAM capable of writing waveform data for 12 tones and a ROM (read-only memory) in which waveform data for 12 tones are preset in advance. Second waveform memory 12 including a memory)
Are provided, and the auto rhythm performance is performed by time-divisionally reading the waveform data from any of the waveform memories (10 or 12) according to the selected rhythm pattern. Writing Waveform Data to First Waveform Memory 10 (FIG. 1) In writing the waveform data to the first waveform memory 10 in the circuit of FIG. 1, the write / read control switch 14 is used.
Turn on. Then, the write / read control signal W / R becomes "1", and the first waveform memory 10 and the lower address data generation circuit 16 enter the write mode. Further, since the gate circuit 18 is turned on, the channel number is displayed on the channel display 20 in accordance with the channel number data CH, and the gate circuit 22 is turned on so that the lower address data WAD for writing is written on the address display 24. The lower address will be displayed accordingly.

RAM / ROM for writing waveform data
The changeover switch 26 is turned on in advance. This way
The memory selection signal RA / RO becomes "1" and the start
The start address memory 28B, which is a RAM in the end address data generation circuit 28, can be used.

By connecting an external device 34 such as a microphone 32 or a tape recorder to the input terminal 30, an arbitrary sound signal (for example, a percussion instrument sound, a signal of a human or animal voice, etc.) can be input. Now, assuming that a desired sound signal is inputted, this input sound signal is supplied to the speaker 38 via the input amplifier 36 and the resistor R ₁ and is sounded, while the level detection circuit 40 is supplied via the input amplifier 36. Is supplied to.

The level detection circuit 40 sets the RS flip-flop 42 almost in synchronization with the rising start of the input signal. Therefore, the output Q of the flip-flop 42 is "1", the write instruction pulse WI _S for start address from the rising differential circuit 44 in response thereto is sent,
It is supplied to the start / end address data generation circuit 28.

In the start / end address data generation circuit 28, when the write / read control signal W / R becomes "1", the channel counter 28A, which is a binary counter, is reset. From this channel counter, the channel number data CH representing the channel number 0 is transmitted, and in response to this, the channel display 20 displays the channel number 0. In the circuit 28, the start address data indicating the start address 0 of the first note is written in the storage area of the start address memory 28B corresponding to the channel number 0 according to the write command pulse WI _S. Then, the start address data is read out immediately after writing and supplied to the adder 46 as the upper address data UAD.

By the way, when the output Q of the flip-flop 42 becomes "1" as described above, the output of the OR gate 48 becomes "1", and this output is supplied to the AND gate 50. A write command pulse WI _S is also supplied to the AND gate 50 via the inverter 52. Therefore, A
The output of the ND gate 50 is delayed by a period corresponding to the pulse width of the Postscript write instruction pulse WI _S output Q becomes "1" of the flip-flop 42 becomes "1", this output write enable signal WEN Is supplied to the lower address data generation circuit 16.

The lower address data generation circuit 16 is provided with a write address counter 16A, which counts the clock signal φ when the write enable signal WEN becomes "1" for writing. Of the lower address data WAD of the
Displays the lower address. Further, the lower address data WAD is supplied to the adder 46 and is added to the above-mentioned upper address data UAD. Then, the addition output from the adder 46 is supplied to the first waveform memory 10 as the address data AD.

The analog / digital (A / D) conversion circuit 54 A / D-converts the input sound signal from the input amplifier 36 at each sample point and represents the amplitude at each sample point in the digital form of waveform data TWD. The first waveform memory 1
Supply to 0.

In the first waveform memory 10, the storage area M ₁ corresponding to the channel number 0 is designated according to the address data AD, and the waveform data TWD for the first one tone is written in this storage area M ₁ . Get caught. In this case, the start address S ₁ of the storage area M ₁ is 0 as described above. Further, the end address E ₁ is determined as described below.

That is, when the level detection circuit 40 resets the flip-flop 42 almost in synchronism with the end of attenuation of the first sound, the output Q of the flip-flop 42 becomes "0" and the output Q'becomes "1". The delay circuit 56 is provided to delay the output Q of the flip-flop 42 by several cycles of the clock signal φ, and when the output Q of the flip-flop 42 becomes “0”, the output of the delay circuit 56 is After a few cycles, the write enable signal WEN becomes "0", and the write enable signal WEN also becomes "0". For this reason,
In the lower address data generation circuit 16, the write address counter 16A stops counting the clock signal φ, and the count value up to this point becomes the end address E ₁ . In this way, by setting the end address a little later than the end of the attenuation of the first note, it is possible to give the storage area M ₁ of the first note a slight margin. The end address E ₁ can be confirmed by looking at the address display 24.

[0019] The fall differential circuit 58, in synchronization with the changes to "0" from the output of the delay circuit 56 is "1" to generate a write instruction pulse WI _E for the end address, start
It is supplied to the end address data generation circuit 28. In this circuit 28, the end address memory 28 composed of RAM
End address data indicating the end address E ₁ is written in the storage area corresponding to the channel number 0 of C in response to the write command pulse WI _E. The written end address data is used to control the reading of the waveform data from the first waveform memory 10.

After the writing process of the waveform data for the first tone is completed as described above, the counter reset switch 60 is turned on. Then, the counter reset signal ACR
Becomes "1", and in response to this, the write address counter 16A in the lower address data generation circuit 16 is reset to the count value 0. Further, the AND gate 62 receiving the output Q ′ = “1” of the flip-flop 42 is
The output becomes "1" in response to the counter reset signal ACR = "1", and the light emitting diode 64 lights up in response to this. The lighting of the light emitting diode 64 indicates that the waveform data of the second sound can be written.

After that, when the step switch 66 is turned on once to generate the step signal SS, the count value of the channel counter 28A in the circuit 28 is incremented by one.
That is, channel number data CH representing the channel number 1 is generated from this channel counter, and the channel indicator 20 displays the channel number 1 in response to this.

Next, assuming that entered the second sound signal through the input terminal 30, a write instruction pulse WI _S in the same manner as described above is generated, a start address memory in the circuit 28 in accordance with this 28B channel number 1
The start address data of the second note is written in the storage area corresponding to. The start address data of the second note represents the start address S ₂ obtained by adding ₁ to the end address E ₁ of the first note. Then, the start address data of the second sound is supplied to the adder 46 as upper address data UAD.

The AND gate 50 generates the write enable signal WEN in the same manner as described above, and in response to this, the write address counter 16A in the circuit 16 adds the write lower address data WAD to the adder 46. Supply to. Therefore, in the same manner as described above, the second waveform data T is stored in the storage area M ₂ corresponding to the channel number 1 of the first waveform memory 10 in accordance with the address data AD from the adder 46.
WD is written.

A little after the end of the attenuation of the second input sound
When the output of the AND gate 50 changes from "1" to "0",
In the same manner as described above, the write address counter in the circuit 16 is
16A stops counting and the count value up to this point
Is the second end address E ₂ Becomes Also, a slight fall
The branch circuit 58 causes the write command pulse WI._E Occurs and responds to this
Then, in the circuit 28, the channel of the end address memory 28C is
End address E in the storage area corresponding to Nel number 1.₂ 
End address data indicating is written.

Thereafter, the counter reset switch 60 is turned on in the same manner as described above, the channel number is incremented by 1 by the step switch 66, and the process of inputting a desired sound signal is repeated to repeat the first waveform. Waveform data for up to 12 tones can be written in the memory 10, which makes it possible to assign 12 rhythm sound sources to 12 tone generation channels. According to such a sequential writing method, the number of addresses of the storage areas M _{1 to} M ₁₂ for 12 sounds in the first waveform memory 10 is determined according to the waveform data amount of the corresponding input sound, and different sounds are input. It is not constant as long as you do.

When it is desired to erase the waveform data written in the first waveform memory 10, the erase switch 65 is turned on. Then, the erase command signal ER, which is the output of the inverter 67 connected to the erase switch 65, becomes "0", the waveform data of the first waveform memory 10 is erased, and the addresses of the start address memory 28B and the end address memory 28C are erased. The data will be erased. Automatic rhythm performance based on stored data (FIG. 1) In the automatic rhythm performance, the first waveform memory 10 is used.
Alternatively, one of the stored data in the second waveform memory 12 is used.

First, the case where the data stored in the first waveform memory 10 is used will be described. In this case, when the write / read control switch 14 is turned off, the write / read control signal W / R becomes "0", and the first waveform memory 10 and the lower address data generation circuit 16 enter the read mode. Further, since the gate circuits 18 and 22 are rendered non-conductive, no display is made on either the channel display 20 or the address display 24.

In the start / end address data generation circuit 28, when the read / read control signal W / R becomes "0", the channel counter 28A counts the clock signal φ and generates the channel number data CH. Since the channel counter 28A is composed of a 12-counter counter, as the channel number data CH, data representing the channel numbers 0 to 11 are sequentially and repeatedly transmitted.

When using the first waveform memory 10, R
Since the AM / ROM changeover switch 26 is turned on in advance, in the circuit 28, the start address memory 28B and the end address memory 28C, each of which is a RAM.
Is available. That is, from the start address memory 28B, 1 is input according to the channel number data CH.
Start address data for 2 channels (12 tones) are sequentially read out, and each start address data is supplied to the adder 46 as upper address data UAD. The end address data for 12 channels is sequentially read from the end address memory 28C according to the channel number data CH, and each end address data EAD is supplied to the comparator 68 as a comparison input B.

The rhythm pattern pulse generation circuit 70 includes a rhythm pattern memory in which a large number of rhythm patterns respectively corresponding to a large number of rhythm types such as march, waltz, swing ... Which rhythm pattern is to be read is designated by the rhythm selection data SEL from the rhythm selector 72.

The rhythm pattern corresponding to each rhythm type is, for example, the count value 0 to the tempo clock pulse count value.
The pattern data corresponding to each count value is composed of one measure of pattern data, and the pattern data corresponding to each count value is set to 1 at the sounding timing corresponding to the count value.
It indicates which channel of the two sounding channels should be sounded.

When the rhythm start / stop switch 74 is turned on, the start / stop control signal ST / SP becomes "1", and in response to this, the rhythm pattern pulse generation circuit 70 follows the rhythm pattern corresponding to the selected rhythm type. The rhythm pattern pulse RP is transmitted in a time division manner. That is, each rhythm pattern pulse is assigned to the time slot corresponding to the channel to be sounded out of the 12 time slots based on the channel number data CH, and the lower address data generation circuit 1 is assigned.
6 and is used as a sounding command signal for the channel.

The lower address data generation circuit 16 is provided with a read address counter 16B capable of counting the clock signal φ in a time-division manner, and this counter is for a channel designated to sound by a rhythm pattern pulse. The clock signal φ is counted at a timing, and the count output is used as the lower address data RAD for reading, and the adder 4
Supply to 6. The lower address data RAD is also supplied to the comparator 68 as the comparison input A.

The adder 46 outputs the upper address data UAD
And the lower address data RAD for reading are added, and the addition output is supplied to the first waveform memory 10 as the address data AD. As a result, from the first waveform memory 10, the address data A
The waveform data is read out in a time division manner according to D. For example, when the rhythm pattern pulse RP is generated to indicate the sound generation in the channels of channel numbers 0 and 2 with respect to a certain sound generation timing, the first waveform memory 10 stores the memory areas M ₁ and M _{3 in} the storage areas M ₁ and M ₃ . The waveform data is read in a time division manner. When the reading of the waveform data is completed for each storage area, the comparator 68 generates the coincidence signal EQ in response to the coincidence of the comparison inputs A and B, and in response to this, the channel relating to the coincidence of the read address counter 16B. The count value corresponding to is reset to zero.

The selector 76 has a memory selection signal RA / R.
Since O is "1", the input A is in a state of being selected.
Therefore, the waveform data read from the first waveform memory 10 is supplied to the accumulator 78 via the selector 76.

The accumulator 78 accumulates read data for a plurality of channels based on the channel number data CH and outputs waveform data representing a mixed waveform. The output data is digital / analog (D / A).
It is converted into an analog signal by the conversion circuit 80. Then, the analog signal from the D / A conversion circuit 80 is supplied to the speaker 38 via the output amplifier 82 and the resistor R ₂ and converted into sound.

As described above, the autorhythm performance is performed by time-divisionally reading the waveform data from the first waveform memory 10 in accordance with the selected rhythm pattern. In this case, an arbitrary rhythm sound source group can be set by rewriting the waveform data of the first waveform memory 10, so that a variety of rhythm performances can be enjoyed.

When it is desired to stop the auto rhythm performance, the rhythm start / stop switch 74 may be turned off.

Next, a case where the data stored in the second waveform memory 12 is used will be described. In this case, setting the write / read control switch 14 to the off state means that the above-mentioned first
Same as the case of using the waveform memory of
The M changeover switch 26 is turned off. Then, the memory selection signal RA / RO becomes "0", and in response to this, the start address memory 2 composed of each ROM in the circuit 28 is formed.
8D and end address memory 28E are available. Further, the selector 76 is in a state of selecting the input B composed of the read data of the second waveform memory 12 in response to the memory selection signal RA / RO = “0”.

Thereafter, when the rhythm start / stop switch 74 is turned on, the auto rhythm performance is performed by the same time division read operation as described above except that the memories 12, 28D and 28E are used instead of the memories 10, 28B and 28C. Is performed. Lower Address Data Generation Circuit (FIG. 2) FIG. 2 shows a configuration example of the lower address data generation circuit 16.

In the write mode, the AND gate 90
Conducts in response to the write enable signal WEN = "1" and supplies the clock signal φ to the write address counter 16A. The counter 16A counts the clock signal φ, and the write lower address data W consisting of the count output.
AD is supplied to selector 92 as input A, while FIG.
It is supplied to the start / end address data generation circuit 28 and the gate circuit 22 as shown in FIG.

Selector 92 has a write / read control signal W /
Input A is selected in the write mode in which R is "1". Therefore, the write lower address data WAD from the counter 16A is supplied to the adder 46 of FIG.

When the write enable signal WEN becomes "0" after the end of the attenuation of the input sound, the AND gate 90 becomes non-conductive, and accordingly, the counter 16A stops counting.

The counter 16A is reset according to the counter reset signal ACR.

In the read mode, the time division latch circuit 94 and the read address counter 16B can be used. The rhythm pattern pulse RP is input to a 12-stage / 1-bit shift register (S / R) 96 which is timed by the clock signal φ. The rhythm pattern pulse sent from the shift register 96 is transferred through the OR gate 98 to a 12-stage / 1-bit shift register (S /
R) 100 and is shifted according to the clock signal φ. Then, the rhythm pattern pulse sent from the shift register 100 is AND gate 102 and OR.
It is input to the shift register 100 again via the gate 98, and thereafter stored cyclically in this closed loop.

The rhythm pattern pulse sent from the shift register 100 is also supplied to the gate circuit 104.
The gate circuit 104 has 12 stages from the adder 106.
It is provided in the data path to the m-bit (m corresponds to the number of bits of the counter 16A) shift register (S / R) 108, and the adder 106 sets "L" to the least significant bit of the output data of the shift register 108. 1 "is added and transmitted, and the shift register 108 performs a shift operation according to the clock signal φ. Therefore, the gate circuit 1
04, the adder 106, and the shift register 108 constitute a time division counter that operates in synchronization with the shift registers 96 and 100.

This time division counter is composed of the shift register 1
For example, when 00 outputs a rhythm pattern pulse at each timing of the 0th channel, the count value is incremented by 1 at each timing corresponding to the 0th channel. The same applies to the timings of the first to eleventh channels. In this way, the counter 16B can perform time division counting for 12 channels.

The count output of the counter 16B is sent as the read lower address data RAD and supplied to the selector 92 as the input B. Selector 92 receives input B in response to write / read control signal W / R = "0" in the read mode.
1 is selected, the read lower address data RAD is supplied to the adder 46 and the comparator 68 of FIG. 1 via the selector 92.

When the coincidence signal EQ is generated from the comparator 68 after the reading of the waveform data for one sound is completed, this coincidence signal is supplied to the inverter 112 via the OR gate 110. Therefore, the AND gate 102 becomes non-conductive in response to the output “0” of the inverter 112, and the rhythm pattern pulse circulated and stored is erased. Therefore, the gate circuit 104 becomes non-conductive at the timing of the matching channel, and the count value corresponding to the channel is reset to zero.

When a rhythm pattern pulse RP having the same channel as the rhythm pattern pulse stored in circulation arrives before the coincidence signal EQ is generated, the rhythm pattern pulse is OR gate 110 and the inverter 11.
Since the AND gate 102 is made non-conductive via 2, the count value of the counter 16B is reset as in the case of the coincidence signal EQ. The rhythm pattern pulse at this time is input to the shift register 100 via the shift register 96 and the OR gate 98, and is cyclically stored as described above. Therefore, the counter 16B starts the counting operation again for the reset channel. As a result, when a rhythm pattern pulse is generated for the same sound while reading the waveform data for one sound, the waveform data can be read back to the head address. Start / End Address Data Generation Circuit (FIG. 3) FIG. 3 shows a start / end address data generation circuit 28.
1 shows an example of the configuration.

In the write mode, the selector 110
Is in a state in which the step signal SS from the step switch 66 of FIG. 1 is selected according to the write / read control signal W / R = “1” and supplied to the channel counter 28B.

When the write / read control signal W / R becomes "1", the channel counter 28B is reset according to the output of the rising differentiating circuit 112 which receives this signal. The channel number data CH representing the count value (channel number) 0 at this time is supplied to the gate circuit 18 of FIG. The data source 1 is used as the input B of the comparator 114.
Data representing the numerical value 1 is supplied from 16.

The comparator 114 compares the inputs A and B and generates an output "1" when A≥B. However, as described above, when the count value of the counter 28A is 0, the output is It is "0". Therefore, the selector 118 receives the data (all bits “0”) indicating the numerical value 0 from the data source 120.
Data) is supplied to the start address memory 28B. At this time, in the memory 28B, the storage area corresponding to the channel number 0 is designated according to the channel number data CH.

Write command pulse W in response to the first input sound
When I _S is generated, the memory 28B is responsive to this pulse.
Start address data indicating 0 is written in the storage area corresponding to the channel number 0 of. When the write command pulse _W IS disappears, the start address data is
It is read from the memory 28B and supplied as the input A to the selector 122.

In the write mode, the selector 122
Is input A in response to the memory selection signal RA / RO = "1".
1 is selected, the start address data read from the memory 28B is supplied to the adder 46 of FIG. 1 as the upper address data UAD via the selector 122.

When the first input sound is attenuated and the counter 16A of FIG. 2 stops counting, the write lower address data WAD representing the count value up to this point is supplied to the end address memory 28C. At this time, in the memory 28C, the storage area corresponding to the channel number 0 is designated according to the channel number data CH.
The write command pulse W is synchronized with the counting stop of the counter 16A.
When I _E is generated, the memory 28C is responsive to this pulse.
Lower address data WAD representing the count value when the counter 16A is stopped is written as end address data in the storage area corresponding to the channel number 0 of. Moreover, the same lower address that was written in the memory 28C data WAD (end address data) is latched by the latch circuit 124 in accordance with the write instruction pulse WI _E.

After that, when the step signal SS is generated, the count value of the counter 28A becomes 1, and accordingly the memory area corresponding to the channel number 1 is designated in the memories 28B and 28C. Also, the counter 28A
When the count value of 1 becomes 1, the output of the comparator 114 becomes "1", and accordingly, the selector 118 causes the adder 1
The output of 26 is selected and supplied to the memory 28B.

The adder 126 receives the end address data from the latch circuit 124 and the numerical value 1 from the data source 128.
Is added to the data representing the start address value which is larger than the end address value by one.

When the write command pulse WI _S is generated in response to the second input sound, the memory 28 is responsive to this pulse.
The output data of the adder 126 is written as the start address data for the second note in the storage area corresponding to the channel number 1 of B.

Thereafter, address data for 12 channels at the maximum can be written in the memories 28B and 28C by the same operation as described above.

The address data written in the memories 28B and 28C can be erased by turning on the erase switch 65 of FIG. 1 and setting the erase command signal ER to "0".

Next, the case of the read mode will be described. In this case, the selector 110 selects the clock signal φ according to the write / read control signal W / R = “0” and supplies it to the counter 28A. The counter 28A counts the clock signal φ so that its count value is 0, 1, 2.
… Changes like 11, 0, 1. The memory 28 according to the channel number data CH corresponding to each count value
Data is read from B, 28C, 28D and 28E, respectively.

Start address memories 28B and 28D
The start address data read from the selector 13 is supplied to the selector 122 as the inputs A and B, respectively, and the end address data read from the end address memories 28C and 28E are input A and the selector B, respectively.
Supplied to zero.

The selectors 122 and 130 both control the selection operation in accordance with the memory selection signal RA / RO. When the first waveform memory 10 is used, RA is selected.
Input A is selected in accordance with / RO = "1". Therefore, as the upper address data UAD, the memory 2
The read data from 8B is sent, and the read data from the memory 28C is sent as the end address data EAD. Further, when the second waveform memory 12 is used, the selector 1 is selected according to RA / RO = "0".
Both 22 and 130 select input B. Therefore, as the upper address data UAD, the memory 28D
From the memory 28E as the end address data EAD. Modified Example of Memory Selection Control Circuit (FIG. 4) FIG. 4 shows a modified example of the memory selection control circuit. The memory selection signal RA ′ / RO ′ transmitted from this circuit is shown.
Is used instead of the memory selection signal RA / RO in the circuit of FIG. 1 only in the read mode.

When the write / read control signal W / R becomes "1" (write mode), the rising differentiating circuit 132 generates an output pulse and a 12-stage / 1-bit shift register (S / R). ) 134 is reset, and the selector 136 is in a state of selecting the input A. When the RAM designating switch 138 is turned on in such a state, the signal “1” is transmitted via the OR gate 140 to the shift register 1
34 is input. As a result, the waveform data in the storage area M ₁ of the first waveform memory (RAM) 10 can be used as the rhythm sound source of the 0th channel. Also, switch 1
Unless 38 is turned on, the waveform data of the storage area corresponding to the channel number 0 of the second waveform memory (ROM) 12 can be used as the rhythm sound source of the 0th channel.

Next, when the step switch 66 of FIG. 1 is turned on once to generate the step signal SS, this signal is supplied to the shift register 134 as a shift pulse SFP through the selector 136, and the shift pulse is shifted accordingly. In the register 134, shift operation for one stage is performed. In this state, it is possible to specify the rhythm sound source of the first channel (select the RAM or ROM by "1" or "0") in the same manner as described above for the 0th channel.

The channel numbers 0 to 1 are set as described above.
"1" (RAM) or "0" (R) for each 1 channel
OM) memory selection is possible, but as an example,
It is also possible to specify "1" for the third channel and "0" for the fourth to eleventh channels. In this case, since the waveform data of the second waveform memory 12 is used as the rhythm sound source for the fourth to eleventh channels, the first waveform memory 1
It is possible to omit writing the waveform data of the fourth and subsequent sounds to 0, and the input operation is simpler than writing the waveform data of 12 sounds.

In the read mode, the selector 136
Selects the clock signal φ according to the write / read control signal W / R = “0”, and supplies it to the shift register 134 as a shift pulse SFP. Therefore, the shift register 13
From 4, signals of “1” or “0” for 12 channels are sequentially read, and each signal is input to the shift register 134 again via the OR gate 140. As a result, from the shift register 134, a time-division multiplexing type memory selection signal R indicating "1" or "0" for each channel.
A '/ RO' will be repeatedly transmitted.

In the read mode, the memory selection signal R
A '/ RO' is changed to the memory selection signal RA / RO in the circuit of FIG.
Used instead of RAMs, including RAMs 28B, 28C and 10 and R including memories 28D, 28E and 12.
The OM group can be switched in a time division manner. Therefore, it is possible to perform an auto rhythm performance using both the rhythm sound source of the first waveform memory 10 and the rhythm sound source of the second waveform memory 12, and change the contents by appropriately changing the stored contents of the shift register 134 and the memory 10. You can enjoy rich rhythm performance. Another Embodiment (FIG. 5) FIG. 5 shows a circuit configuration of an electronic musical instrument provided with an automatic accompaniment apparatus according to another embodiment of the present invention. The same parts as those in FIG. And show it. The feature of this embodiment is that the present invention is applied to automatic bass sound generation.

The keyboard circuit 150 is a first circuit for playing a melody.
Of the keyboard and the second keyboard for accompaniment.
The key operation information is detected by 52.

The key operation information detected from the first and second key ranges is supplied to the tone forming circuit 156. The tone forming circuit 156 forms tone signals such as a melody tone signal and a chord tone signal based on the supplied key operation information, and the resistor R ₃
Is supplied to the speaker 38 via. Therefore, the speaker 3
From 8, a musical tone corresponding to the key pressed in the first and / or second key range is generated.

The key operation information detected from the second key range is
It is supplied to the base pattern pulse generation circuit 158. Rhythm selection data SEL is also supplied from the rhythm selector 72 to the circuit 158.

The base pattern pulse generation circuit 158
It includes a chord name detection circuit, a bass pattern memory, a pitch determination circuit, and the like.

The chord name detection circuit detects the chord name (root note and chord type) based on the supplied key operation information. The bass pattern memory stores bass patterns corresponding to chord types such as major, minor, and sevens for each rhythm type.
Each bass pattern includes pitch data representing a pitch for a root note of a bass sound to be sounded at each sounding timing. The pitch data of the bass pattern corresponding to the selected rhythm type and the detected chord type is read from the bass pattern memory. The pitch determining circuit determines the pitch of the bass note to be pronounced based on the detected root note and the read pitch data, and assigns the base pattern pulse BP to the time slot corresponding to the pitch. Send out.

The bass tone generator BTG has the same structure as the rhythm tone generator RTG described above, and can input any twelve tones. The input sound signal is sent to the speaker 3 via the resistor R _4.
8 and is converted into sound.

The base pattern pulse BP is supplied to the lower address data generation circuit 16 'having the same structure as the lower address data generation circuit 16 described above, instead of the rhythm pattern pulse RP. The first waveform memory (corresponding to the memory 10 in FIG. 1) including the RAM in the bass tone generator BTG is
Waveform data for 12 sounds can be sequentially written, and as an example, the bass sounds of G ₂ , G ^# ₂ , A ₂ , A ^# ₂ and B ₂ and C ₃ ,
^{_{C # 3, D 3, D}} # 3, and the bass guitar sound of the E _3, F _3, F
Waveform data corresponding to the guitar sound of ^# ₃ can be sequentially written. In this case, if the above-described bass pattern pulse BP is assigned to the time slot corresponding to the 11th channel, for example, the guitar tone signal of F ^# ₃ is sent from the bass tone generator section BTG. Then, the guitar sound signal is supplied to the speaker 38 via the resistor R ₅ and converted into sound.

According to the embodiment shown in FIG. 5, the bass sound source group to be used for the automatic bass performance can be arbitrarily set, and the bass performance rich in variations can be enjoyed.

In the above embodiment, the rhythm pattern,
Although the factory-set accompaniment pattern such as the bass pattern is used, the accompaniment pattern may be arbitrarily set (programmed) by the user.

The present invention can also be applied to the generation of auto arpeggio sounds.

[0080]

As described above, according to the present invention, the writing of the waveform data is automatically stopped upon detecting that the input sound signal is attenuated to a predetermined level, so that the utilization efficiency of the waveform memory is improved. And the effect that faithful reproduction is possible is obtained.

Moreover, if the writing of the waveform data is stopped in response to the signal obtained by delaying the attenuation detection signal by the predetermined time, the waveform data of the sound wave-shaped attenuating portion can be sufficiently stored, so that more faithful reproduction is possible. You can also get the effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of an autorhythm device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a lower address data generation circuit in FIG.

3 is a circuit diagram showing a configuration example of a start / end address data generation circuit in FIG.

FIG. 4 is a circuit diagram showing a modified example of a memory selection control circuit.

FIG. 5 is a block diagram showing a circuit configuration of an electronic musical instrument having an automatic accompaniment apparatus according to another embodiment of the present invention.

[Explanation of symbols]

10: waveform memory, 16: lower address data generation circuit, 28: start / end address data generation circuit,
30: input terminal, 40: level detection circuit, 54: A / D
Conversion circuit, 56: delay circuit, 70: rhythm pattern pulse generation circuit, 80: D / A conversion circuit, 158: bass pattern pulse generation circuit, RTG: rhythm tone generator, BT
G: Bass sound source section.

Claims (2)

[Claims] 1. Input means for inputting a sound signal, readable / writable waveform storage means, and writing means for writing waveform data representing a waveform of a sound signal input from the input means into the waveform storage means. Detecting means for generating a detection signal by detecting that the level of the sound signal input from the input means has dropped below a predetermined value after the writing of the waveform data is started, and the detection signal from the detection means. A waveform storage / reproduction device comprising: stop control means for controlling the writing means to stop writing of the waveform data based on the waveform data; and reproduction means for reading the waveform data from the waveform storage means and reproducing a sound signal. 2. Input means for inputting a sound signal, readable / writable waveform storage means, and writing means for writing waveform data representing a waveform of a sound signal input from the input means into the waveform storage means. Detecting means for generating a detection signal by detecting that the level of the sound signal input from the input means has dropped below a predetermined value after the writing of the waveform data is started, and the detection signal from the detection means. Delay means for delaying by a predetermined time; stop control means for controlling the writing means to stop the writing of the waveform data according to the delayed signal from the delay means; and waveform data from the waveform storage means. A waveform storage / reproduction device having reproduction means for reading and reproducing a sound signal.