JPH08152884A - Sound source device - Google Patents

Abstract

PURPOSE: To make a musical sound waveform generation means generating a musical sound waveform of a pronounced musical sound an independent system, to reduce the load on a sound source system performing generation processing of a musical sound signal and to facilitate the exchange of a waveform memory. CONSTITUTION: A DCO 44 constituting the system independent of a DSP 30 constituting a main part of a PCM sound source device SB is provided as the external circuit of the DSP 30. A CPU 23 controlling the whole computer executes a musical sound generation program to send a sound source control parameter to the DSP 30. The DSP 30 transfers an address generating parameter required for accessing a waveform memory 41 to the DCO 44. The DCO 44 reads out the musical sound waveform data from the waveform memory 41 based on the transferred address data to send them to the DSP 30. The DSP 30 has processing power to spare by shifting the access processing of the waveform memory to the DCO 44, and performs envelope control processing and weighting processing, etc., at a high speed, and increases the number of voices, too. Further, since the exchange of the waveform memory 41 can be dealt with by the revision of the DCO 44, the exchange is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone generator device for improving the efficiency and function of the tone generation processing operation of a digital tone generator.

[0002]

2. Description of the Related Art Conventionally, a PCM tone generator S as shown in FIG.
A is known. The PCM sound source device SA is an external connection unit, and is connected to a programmable computer such as a personal computer, which can execute various software. This PCM sound source device SA
Includes a DSP (digital signal processor) 3, and the DSP 3 transmits and receives various data to and from the control CPU 1 of the connected computer.
The PCM tone generator SA includes a waveform memory 2 for storing musical tone waveform data, a program memory 4 for storing a program for the DSP 3, a work memory 5 for the DSP 3, and a DAC.
A (D-A converter) 6, an amplifier 7, and a timing generation circuit 9 are provided. The DSP 3 exchanges various data with the waveform memory 2, the program memory 4, and the work memory 5. Further, an interrupt signal is input to the DSP 3 from the timing generation circuit 9 and the operation timing of the DSP 3 is controlled. The tone signal data generated by the DSP 3 is converted into an analog signal by the DAC 6,
It is amplified by the amplifier 7 and sent to the speaker 8.

The DSP 3 executes processing according to the processing program of the DSP 3 stored in the program memory 4 to generate musical tone waveform data. FIG. 14 is a functional diagram showing the processing executed by the DSP 3. The interface unit 10 sends and receives data such as parameters, programs and waveform data to and from the CPU 1. The main processing unit 11 transfers the parameters sent from the CPU 1 to the work memory 5, the DCO 12, and the DCA 14. A DCO (Digital Controlled Oscillator) 12 generates an address for the waveform memory 2 according to the contents of the address parameter given from the main processing unit 11. The interpolating unit 13 interpolates between the samples of the musical tone waveform data read from the waveform memory 2 by the address. DCA (digitally controlled
The amplifier 14 controls the amplitude of the musical tone waveform data interpolated by the interpolation unit 13 according to the contents of the parameters given from the main processing unit 11. The accumulator 15 is
The output from the DCA 14 is distributed to a plurality of output systems, weighted for each system and accumulated, and then the tone signal data is output to each system.

[0004]

However, all the processes for generating the tone signal data as described above are performed by one D
In the case of performing with SP3, if it is tried to perform a lot of processing in order to enhance the function of the sound source device, a high-speed and large-capacity DSP
The cost will increase significantly. In addition, the process of reading musical tone waveform data from the waveform memory 2 is performed by one DS.
In the configuration performed by software inside P3, when it is necessary to replace the waveform memory 2, the waveform memory 2
The program relating to the DCO 12 must be changed in accordance with the replacement. This is because replacement of the waveform memory 2 is difficult because the processing program of the CPU 1 has to be rewritten.

The present invention has been made to solve the above problems, and an object of the present invention is to enhance the function of a sound source device without increasing the cost and facilitate the replacement of a waveform memory. It is in.

[0006]

In order to achieve the above object, the present invention uses a musical tone waveform generating means for generating a musical tone waveform of a musical tone to be sounded, by allocating a plurality of musical tone channels and outputting them by time division. This is an independent system separate from the allocation output means.

[0007]

As a result, the load on the musical tone signal allocation and output means is reduced. Further, since the musical tone waveform generating means is an independent system, when the waveform memory for generating the musical tone waveform is replaced, it can be easily replaced without affecting the allocation output means.

[0008]

[Example] 1. Overall Circuit FIG. 1 shows the overall circuit of the PCM tone generator SB. This PC
The M sound source device SB is an external connection unit of the computer PC and is attachable to and detachable from the computer PC. The computer PC is, for example, a personal computer or the like, is programmable, and can execute various software. In this PCM tone generator SB, a DSP (digital signal processor) 30, a waveform memory 41 for storing musical tone waveform data, a program memory 45 for storing a program of the DSP 30, a DCO 44, a DSP 30.
The work memory 42, the DAC (DA converter) 47, the amplifier 48, and the timing generation circuit 46 are mounted on one board.

The DSP 30 sends and receives various data to and from the control CPU 23, the waveform memory 41, the program memory 45, the work memory 42, and the DCO 44 of the computer PC to which the PCM tone generator SB is connected.
Further, the interrupt signal from the timing generation circuit 46 is DSP3.
0, and the operation timing of the DSP 30 is controlled. The tone signal data generated by the DSP 30 is
After being converted into an analog signal by the DAC 47, it is amplified by the amplifier 48 and sent to the speaker 49. The program memory 45 may be ROM or RAM.

The DSP 30 has the program memory 45.
The processing is executed in accordance with the processing program of the DSP 30 stored in, to generate musical tone signal data. Figure 2 is DS
The processing executed by the P30 is shown in functional blocks. The main processing unit 32, the DCA 34, the accumulating unit 35, and the interpolating unit 36 are configured so that the DSP 30 includes the program memory 4
5 shows respective partial functions when executing the respective processing programs stored in FIG.

The interface section 31 transmits / receives data such as parameters, programs and waveform data to / from the CPU 23. The main processing unit 32 transfers the parameters sent from the CPU 23 to the work memory 42,
The data read from the work memory 42 is transferred to the DCO 44,
The data is transferred to the DCA 34 and the interpolation unit 36. The main processing unit 32 also calculates the envelope. The interface unit 33 sends and receives parameters, waveform data, and the like to and from the DCO 44, which is an external circuit. The interface unit 33 includes a memory 37.

The DCA 34, according to the contents of the envelope control parameters given from the main processing section 32,
The envelope waveform data is combined with the musical tone waveform data interpolated by the interpolation section 36 to control the amplitude of the musical tone waveform data. The accumulating unit 35 distributes the output from the DCA 34 to a plurality of output systems, weights each system, and accumulates,
Outputs tone signal data to each system. The interpolation section 36 interpolates between the samples of the musical tone waveform data read from the waveform memory 41 by the address.

The DCO 44 is an external circuit independent of the DSP 30 and calculates an address parameter given from the main processing section 32 to generate an address for accessing the waveform memory 41. The waveform memory 41 is a memory for storing musical tone waveform data, and may be ROM or RAM, and may be of a type fixed to the PCM tone generator SB or a detachable type. However,
In the case of a RAM, an address bus and a data bus are provided between the waveform memory 41 and the CPU 23, and a means for switching between these buses and the address bus and the data bus between the waveform memory 41 and the DSP 30 is provided. C
It is necessary to be able to transfer musical tone waveform data from the PU 23 to the waveform memory 41. This DCO44 is a CPU
It can be configured by a microcomputer including the above, a DSP, or the like.

The timing generation circuit 46 gives timings for arithmetic processing and data output processing in the DSP 30, and gives an interrupt signal to the DSP 30 at a cycle corresponding to the sampling frequency of the musical tone waveform data. The DSP 30 uses the interrupt signal as a trigger to perform a tone signal generation process and a tone signal output process. The timing generation circuit 46 also supplies a system clock signal and the like to the circuits shown in FIGS.

2. Channel Assignment Process by CPU FIG. 3 is a flowchart of the channel assignment process executed by the CPU 23. A music generation program is read into the computer PC, and tone generation data is input by key input. In the RAM 24, sound source control parameters corresponding to the key input data are stored based on the tone generation program in addition to the key input data. The process shown in FIG. 3 is a part of the sound generation process in the music generation program by the computer PC, and is started by an interrupt when there is key-on event data during the execution of the sound generation process. First, the channel count data n is reset to "0" (step 8).
0), it is determined whether or not the on / off data of channel 0 in the channel memory area 50 described later is "0" (step 82). This on / off data is "0"
If so, the channel count data n is incremented (step 84). If this on / off data is "1", the key number data and sound source control parameter of the key for which the key-on event is instructed are written in the n-channel CHn of the channel memory area 50 (step 86). The above processing is performed for all channels (step 88). Here, the total number of pronunciations is
It is the number of tones (voices) that can be sounded simultaneously.

The channel memory area 50 is formed in the RAM 24 by a tone generation program. As shown in FIG. 4, the channel memory area 50 has N channel memory areas divided into channels CH1 to CHN-1. And
On / off data of each voice, key number data, and sound source control parameters are stored in the memory area of each channel.

In the channel memory area 50, the channel to which the key-off event is instructed needs to be an empty channel. Therefore, the CPU 23 executes the key-off event process shown in FIG. This key-off event process is a part of the sound generation process in the musical tone generation program, and is started by an interrupt when the key-off event is instructed to the voice being sounded. In this processing, the channel in which the same key number as the key for which the key-off event is instructed is stored is searched from the channel memory area 50 (step 90). Then, the on / off data of the channel storing the same key number is rewritten to "0" (step 92). As a result, when the channel allocation process is performed next, the key for which the key-on event is instructed is allocated to the vacant channel in which the on / off data is set to "0" (step 82,
86).

The above channel allocation processing is
It may be executed by the DSP 30. In this case,
When the CPU 23 transfers the sound source control parameter relating to the key for which the key-on event is instructed to the DSP 30,
The DSP 30 performs a process of allocating the transferred data to the channel area in the work memory 42. Further, the key-off event process is performed by the CPU 23 transferring the key number data of the key instructing the key-off event to the DSP 30, and the DSP 30 based on the transferred key number data.

3. Memory Map of DSP FIG. 6 is a memory map of the DSP 30 . Data stored in the work memory 42 is assigned to the first half of the address, and the interface unit 33 is provided to the rear of the address.
The data stored in the memory (DCO-I / F memory) 37 of FIG. In the work memory 42, C
The sound source control parameters for each voice of N channels transferred from the PU 23 via the DSP 30 are stored. The sound source control parameters are classified into address generation parameters for reading musical tone waveform data and envelope control parameters for musical tone waveform data.

In each channel area, a start address ST, a loop top address LT, a loop end address LE, and angular frequency data ω are stored as address generation parameters, and a target level LV and an envelope speed SP are stored as envelope control parameters. Is memorized. In addition, when the output sequence is left and right for stereo audio output, panpot data PAN is further stored as an envelope control parameter. Start address ST, loop top address L
The T, the loop end address LE, the target level LV, and the envelope speed SP are determined in accordance with the tone pitch (tone range) (key number), tone color (tone number), and touch data that are keyed to the computer PC. Further, the angular frequency data ω is determined according to the pitch (tone range) (key number) key-input, and the panpot data PAN
Is determined according to the sound image data input by the key.

At the address indicated by (W) in the figure of the DCO-I / F memory 37, the current address value Σa of the sound source control parameters read from the work memory 42,
Loop top address LT, loop end address L
E, angular frequency data ω is stored. Also, in the figure (R)
The address displayed as is a new address value ΣA obtained from the current address value, the current value W0 of the waveform data read from the waveform memory 41, and the future value W1 of the waveform data.
Is stored. The future value W1 of this waveform data is the waveform data one sample point after the current value W0 of the waveform data. In addition, registers 50 to 55 for temporarily storing parameters and the like used in the arithmetic processing and the like in the main processing unit 32 are provided.

4. Main Processing by DSP FIG. 7 is a flowchart of main processing executed by the DSP 30 . This process is started when the power is turned on, and the initialization process is performed when the power is turned on (step 100). Then, it is determined whether or not the sound source control parameter has been transferred from the CPU 23 (step 102). When the sound source control parameter is transferred, the sound source control parameter is received by the DSP 30 (step 104), transferred to the work memory 42, and stored in a form of being collected for each voice (step 10).
6).

The CPU 23 performs the above-mentioned channel allocation processing to generate a sound source control parameter relating to a musical sound to be generated, based on key on / off data, pitch (tone range) data, touch data, tone color data, sound image data, and the like. Are stored in the channel memory area 50 provided in the RAM 24. Then, when this channel allocation processing is completed, the CPU 23 transfers the sound source control parameters for all voices to the DSP 30.

The DSP 30 repeats the reception mode processing (steps 102 to 106) for receiving the sound source control parameter and transferring it to the work memory 42. And D
When the SP 30 receives the interrupt signal from the timing generation circuit 46, the PCM sound source operation mode flag is set. In step 108, it is determined whether or not this PCM sound source operation mode flag is set. If this PCM sound source operation mode flag is set, the tone signal generation processing of step 110 and subsequent steps is executed. It First, by the time the generation of the tone signals of all voices is completed, interrupt prohibition processing is performed so that the processing is not interrupted by the next interrupt signal (step 110).
Next, the channel count data n is cleared (step 112), the tone generation processing of the tone of the n channel is executed (step 114), and the channel count data n is incremented by "1" (step 116).

When tone generation processing is performed on N channels from channel 0 to channel N-1 (steps 114, 116, 118), the register 54,
The accumulated value data for each output series of the musical tone waveform data for N channels stored in 55 is output from the DSP 30 to the DAC 47 as the musical tone signal data SD (step 120). As described above, the DSP 30 executes the generation of the musical tone waveform of the key assigned to the N channel by the CPU 23 by switching the channel at an indefinite period or a constant period by the time division processing, and outputs the musical tone waveform of each channel in a time division manner. . When the output processing of the tone signal data is completed, the accumulated value data is cleared, and then the PCM
The sound source operation mode flag is reset (step 12
2) The interruption prohibition is released (step 124).
Then, the sound source control parameter reception mode processing is performed again (steps 102 to 106).

5. Sound Generation Process by DSP FIG. 8 is a flowchart of the sound generation process (step 114) in FIG. First, the address generation parameter of the tone generator parameters relating to the tone of the n-channel stored in the work memory 42 is read (step 20).
0). Then, the address generation parameters read by the DSP 30 together with the current address value data Σa are transmitted via the interface unit 33 to the DCO 4 of the external circuit.
4 (step 202). Of the address present value data Σa, the lower decimal part is sent to the interpolation section 36. Next, the envelope control parameters of the sound source parameters related to the musical sound of the n channel stored in the work memory 42 are read (step 204),
Based on this envelope control parameter, the envelope of the tone of n channels is calculated.

Current address value Σ transferred to DCO 44
The upper integer part of a is sent to the waveform memory 41, and the tone waveform data of the corresponding address is read out. The read tone waveform data is stored in the DCO-I / F memory 37 of the interface unit 33 as the waveform data current value W0. Further, the integer part of the current address value Σa is incremented in the DCO 44 and sent to the waveform memory 41 after a predetermined time, so that the musical tone waveform data one sample point after the current waveform data value is read from the waveform memory 41. Be done. The read musical tone waveform data is set as the waveform data future value W1 by the DCO.
-It is stored in the I / F memory 37.

After performing the envelope calculation, the main processing section 32 reads out the waveform data present value W0, the waveform data future value W1 and the new address value ΣA stored in the DCO-I / F memory 37 (step 208). ). The read new address value ΣA is stored in the n-channel area of the work memory 42 by the main processing unit 32 (step 210).

Next, the interpolator 36 calculates the current address value Σ.
Using the lower decimal part of a, the waveform data is linearly interpolated from the waveform data present value W0 and the waveform data future value W1 (step 212). If the DSP 30 has a processing time margin, for example, instead of the linear interpolation processing, the interpolation processing by the least square method, the interpolation processing by the spline function method, or other interpolation processing may be executed. And D
The CA 34 multiplies the interpolation value W of the tone waveform data obtained by the interpolation processing by the envelope level E calculated by the main processing section 32 (step 21).
4). Musical sound waveform data EW obtained by this multiplication
In the accumulator 35, weighting is performed for each output sequence, that is, for each sound image sequence using the panpot data, and accumulated for each output sequence (step 216).

6. The envelope calculation process executed in step 206 of envelope calculation process by DSP is performed as follows. In the CPU 23, if the voice of the n-channel for which the channel allocation processing has been performed is the key-on event, the target level LV of the attack phase and the decay phase and the envelope speed SP are set to D.
Send to SP30. If the n-channel voice is the key-off event, the target level L of the release phase is
Send V and envelope speed SP to DSP 30.
As described above, these parameters are stored in the work memory 4
2 (FIG. 7, step 106), step 20
It is read into the DSP 30 at step 4.

Then, in step 206, the envelope level E of the n-channel voice is obtained by the following calculation.

Et + 1 = Et + SP (LV-Et) (1) where Et + 1 is the current value of the envelope and Et is the envelope value one sampling period before. The present value Et + 1 of the envelope level obtained by this calculation is stored in the register 51.

Interrupt processing of FIG. 7 (steps 110-1)
The calculation of the equation (1) is performed each time 24) is repeatedly performed, and the current envelope level Et is equal to the target level LV.
The velocity changes toward the envelope speed SP. When the current envelope level Et approaches the target level LV with an error within a certain range, the target level LV and the envelope speed S of the next phase are set.
The operation of equation (1) is performed using P. The envelope phase is switched in the order of attack, decay, and release.

The determination of the phase switching timing may be performed entirely within the CPU 23 or the DSP 30.
You can go some inside. When all the processing is performed in the CPU 23, the target level LV and envelope speed SP of the next phase are transferred to the work memory 42 via the DSP 30 each time the phase changes. Further, when a part of the processing is performed in the DSP 30, the timing of switching from attack to decay is determined in the DSP 30, and the CP
U23 sends the target level and envelope speed of the attack phase and the target level and envelope speed of the decay phase to the DSP 30 at the same time when the event occurs. Further, the CPU 23 sets the target level and the envelope speed of the release phase to the DS at the off event.
Send to P30. As a result, the phase determination processing in the CPU 23 can be reduced and the processing capacity of the CPU 23 can be afforded.

7. The interpolation processing of the musical tone waveform data executed in the interpolation processing step 212 by the DSP is performed as follows. In step 208 DCO-I
The current waveform data value W0 and the future waveform data value W1 are read from the / F memory 37. Then, in step 212, linear interpolation of the musical tone waveform data is performed using the decimal part Σai of the current address value read from the DCO-I / F memory 37. The interpolation value W of the waveform data obtained by this linear interpolation is obtained by the following calculation.

W = W0 + Σai (W1−W0) (2) For example, if W0 = 1.0, W1 = 3.0, and Σai = 0.6, then W = 1.0 + 0.6 (3.0-1) .0) = 2.2. By generating the musical tone waveform using the interpolation value W of the waveform data, the musical tone waveform deformed by the PCM can be approximated to the original waveform. The waveform data interpolation value W is stored in the register 52.

8. Panpot and tone waveform by DSP
The accumulation processing of panpot and tone waveform data executed in the data accumulation processing step 216 is performed as follows. DSP30
Determines whether the panpot data PAN is positive or negative when the sound source control parameter is sent from the CPU 23. That is, the panpot data PAN is 1 as shown in FIG.
It is 6-bit data, and whether the MSB is “0” or “1” is used to determine whether it is positive or negative. When the MSB is “0”, the panpot data PAN is transferred to the work memory 42 as it is. When the MSB is “1”,
After masking the MSB, a process of taking a 2's complement is performed, and then the data is transferred to the work memory 42. In step 216, the pan pot data PAN is converted to the musical tone waveform data E.
This is a preprocessing for multiplying W. As a result, weighting can be performed only by multiplication regardless of whether the panpot data PAN is positive or negative.

After such pre-processing is performed, the DSP 3
At 0, the processing shown in FIG. 10 is executed. First, the panpot data PAN is read from the work memory 42 (step 230), and it is determined whether the MSB is "0", that is, the panpot data PAN is positive (step 232). If the panpot data PAN is positive,
The output level of the tone waveform data W (L) of the left channel remains the tone waveform data EW obtained in step 214 (step 234), and the tone waveform data W of the right channel W
The output level of (R) is set to a value obtained by multiplying the tone waveform data EW by the panpot data PAN (step 236).
As a result, as shown in the left half of FIG. 9, the output level of the musical tone waveform data W (L) of the left channel does not change, and the output level of the musical tone waveform data W (R) of the right channel changes to the panpot data PAN. The weighting is performed so as to increase in proportion to the value of.

If the MSB is "1" in step 232, the tone waveform data W (L) of the left channel is obtained.
Is set to a value obtained by multiplying the tone waveform data EW by the panpot data PAN (step 238), and the output level of the tone waveform data W (R) of the right channel remains the tone waveform data EW (step 240). As a result, as shown in the right half of FIG. 9, the output level of the tone waveform data W (R) of the right channel does not change, and the output level of the tone waveform data W (L) of the left channel is the panpot data. Weighting is performed so as to decrease in inverse proportion to the value of PAN.

The tone waveform data W (L) and W (R) of the left and right channels after this weighting processing are stored in the registers 54 and 55 separately for the left and right channels, and the accumulated values WL up to the previous processing, It is added to WR, and the addition result is updated and stored as a new accumulated value (steps 242, 2).
44). Then, this weighting process is performed for channels 0 to N.
By being executed for the -1 channel, the accumulated values of the tone waveform data after weighting for N channels are stored in the registers 54 and 55.

9. DCO FIG. 11 is a block diagram showing the contents of the address calculation performed by the DCO 44. The parameters transferred from the DSP 30 are temporarily stored in the register 44R, and the parameters are read out from the register 44R at a predetermined timing and the calculation is performed. The bank data Bank is an address upper extension value and is output to the waveform memory 41 as it is. The address present value Σa is output to the waveform memory 41 with its integer part Σai being read out as address data, incremented by the adder 62, and output as the interpolation address value Σai + 1 to the waveform memory 41 after a predetermined delay time. The current address value Σa starts from the start address and increases by an angular frequency ω at regular intervals. The angular frequency ω is data determined according to the pitch.

The angular frequency ω is added to the current address value Σa in the adder 60. This value (Σa + ω) is the next address value Σα to be used when the next interrupt process is performed. However, this next address value Σα is sent to the adder 61 via the inverter 64 for performing looping processing. In the adder 61, the difference Δa (= L between the loop end address LE and the next address value Σα
E−Σα) is calculated. Calculation result of this adder 61
The carry data carry indicating the sign of a is gate 66.
Sent to. The carry data carry is “0” when Δa is positive and is “1” when Δa is negative.
In the gate 66, if the carry data carry is "0", the loop end address LE passes, and if it is "1", the loop top address LT passes. Δa is sent to the adder 63 via the inverter 65, and the adder 6
In 3, when Δa is positive, LT-Δa is calculated,
When a is negative, LE-Δa is calculated.

New address value Σ output from adder 63
A is ΣA = LE−Δa = Σα (carry
= “0”) ΣA = LT−Δa = LT + | Δa | (carry
= "1"). The new address value ΣA is sent to the DCO-I / F memory 37, is updated and stored in the address storage area of the corresponding channel of the work memory 42, and is read as the current address value Σa in the next process.

10. Address arithmetic processing by DCO The DCO 44 may be configured by an arithmetic circuit for performing arithmetic as shown in FIG. 11 by hardware, or the above address by software using an arithmetic processing device such as a CPU or DSP. You may make it perform a calculation. FIG. 12 shows a flowchart in the case where the DCO 44 performs address calculation by software.

When parameters relating to the n channel are sent from the DSP 30, these parameters are sent to the DCO4.
4 is stored in the register 44R. Then, first, the current address value Σa is read from the register 44R (step 300). Next, in the DCO 44, a process for updating the current address value Σa read in step 300 is performed. That is, the angular frequency ω is read from the register 44R (step 302) and added to the current address value Σa (step 304). This calculation result (Σa + ω) becomes the next address value Σα. Next, the loop top address LT and the loop end address LE are read from the register 44R (step 30).
6). Then, Δa (= LE−Σα) is calculated (step 308).

When .DELTA.a is positive, that is, when the next address value .SIGMA..alpha. Is smaller than the loop end address LE, LE-.DELTA.a = .SIGMA..alpha. Is set as the new address value .SIGMA.A at step 314, and this new address value .SIGMA.A is set to DCO. -It is written in the I / F memory 37 (step 316). here,
The purpose of the calculation is to match the number of steps with the process of step 312, and the next address value Σα may be directly written to the new address value ΣA without performing this calculation.

On the other hand, when Δa is negative, the next address value Σα exceeds the loop end address, so LT-Δa is calculated (step 312) and the address value is set to the loop top address LT. Bring it closer. That is, the next address value Σα is the loop end address L
The amount | Δa | that exceeds E is added to the loop top address LT, and this value (LT + | Δa |) is the new address value Σ.
A is written in the DCO-I / F memory 37 (step 316).

By the processing of steps 310, 312, and 314, the new address value ΣA is returned from the loop end address LE to the loop top address LT, and is repeatedly increased by the angular frequency ω. That is, after the address value increased from the start address passes through the loop top address LT, the loop address is looped by repeatedly updating the address value between the loop top address LT and the loop end address LE.

When the updating process of the address value is completed in this way, the process of accessing the waveform memory 41 is performed next. Again, the current address value Σa is read (step 318), and the waveform memory 41 is accessed by this current address value Σa (step 320). The waveform data present value W0 read by this access processing is stored in the DCO-I / F memory 37 (step 322) and is incremented in the DC044 (step 324). The waveform memory 41 is accessed by the incremented address value Σa + 1 (step 326) and the future waveform data value W1 is read (step 328). This future waveform data value W1 is stored in the DCO-I / F memory 37.

As described above, in this embodiment, the main processing of the PCM tone generator is performed by the DSP 30, and the processing of reading the required waveform data from the waveform memory 41 is performed by the DCO 44 provided as an external circuit. , The processing burden on the DSP 30 is reduced, and high-speed processing becomes possible. Further, by using the DCO 44 as an external circuit for accessing the waveform memory 41 as an external circuit, when the waveform memory 41 is exchanged, it can be dealt with only by changing the configuration or the program of the DCO 44, and the general-purpose machine can be easily provided. . For example, the waveform memory 41 is removable R
Even if it is an OM card or RAM card, the DCO
Since this can be dealt with by changing the configuration in which 44 can access a ROM card or the like, the specification can be changed easily and at low cost. In this case, DCO44 and ROM or RAM
It is also possible to use a built-in IC card in a single card.

The present invention is not limited to the above embodiment, but various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, the CPU 23 and the DSP 30
And the DCO 44 are the interface units 31, 33
Since the data is transmitted and received via the terminals, they operate asynchronously with each other, but they may operate in synchronization with each other.

Further, in the above embodiment, the CPU 23 and the DS
Since the P30 and the DCO 44 operate as independent systems, each is timed by its own clock signal, but each may be operated by the same clock signal.

The configuration of the sound source device of the above embodiment is merely an example, and the present invention can be applied to various sound source devices having other additional functions such as reverberation effect and resonance effect. Further, the present invention can be applied to not only the PCM type sound source device but also another type of sound source device, for example, a harmonic synthesis type sound source device.

The number of output sequences, which is two in the above embodiment, may be one or three or more, and the various operations performed in the above embodiment may be adjusted by other adjustments. Multiplication / division, or data shift of the other data by one data, or calculation by a calculation formula in the calculation circuit,
A data table may be provided in the memory to substitute the calculation data such as reading the calculation data.

A part or all of the processing executed by the DSP 30 may be executed by the CPU 23 of the computer PC, or the DAC 47, the amplifier 48 and the speaker 49 may be built in the computer PC.

Further, although the present invention has been described as a sound source device which is attachable / detachable to / from the personal computer PC, the sound source device may be incorporated in the personal computer PC itself, or may be a sound source device attachable / detachable to / from an electronic musical instrument. .

[0057]

As described above in detail, according to the present invention, the musical tone waveform generating means for generating the musical tone waveform of the generated musical tone is assigned output means for performing channel assignment and time-division processing of a plurality of musical tones. Was another independent system. This reduces the load on the allocation output means. Therefore, the present invention can improve the efficiency and the function of the tone generation processing operation of the digital sound source, for example,
It is possible to increase the number of voices, and it is possible to produce musical tones that are rich in expression with a larger number of pronunciations than before.

Further, since the musical tone waveform generating means is an independent system, when the waveform memory for generating the musical tone waveform is replaced, it can be easily replaced without affecting the allocation output means. Therefore, according to the present invention, it is possible to easily change the specifications relating to the access to the waveform memory at low cost and to provide a general-purpose machine.

[Brief description of drawings]

FIG. 1 is an overall circuit diagram of a sound source device.

FIG. 2 is an overall circuit diagram showing the processing of a DSP 30 in blocks.

FIG. 3 is a diagram showing a flowchart of a channel allocation process executed by a CPU 23.

FIG. 4 is a diagram showing a channel memory area in a RAM 24.

FIG. 5 is a diagram showing a flowchart of key-off event processing executed by the CPU 23.

FIG. 6 is a diagram showing a memory map of the DSP 30.

FIG. 7 is a diagram showing a flowchart of a main process executed by the DSP 30.

FIG. 8 is a diagram showing a flowchart of a sound generation process in the main process.

FIG. 9 is an explanatory diagram of a pan pot process executed by the DSP 30.

FIG. 10 is a diagram showing a flowchart of a pan pot and accumulation process executed by the DSP 30.

FIG. 11 is a diagram showing an arithmetic circuit of DC044.

FIG. 12 is a diagram showing a flowchart of address calculation processing executed by the DCO 44.

FIG. 13 is an overall circuit diagram of a conventional sound source device.

FIG. 14 is an overall circuit diagram showing blocks of processing of a DSP 3 in a conventional sound source device.

[Explanation of symbols]

PC ... Computer, SB ... PCM tone generator, 23 ... C
PU, 24 ... RAM, 30 ... DSP, 31 ... Interface section, 32 ... Main processing section, 33 ... Interface section, 34 ... DCA, 35 ... Accumulation section, 41 ... Waveform memory, 42 ... Work memory, 44 ... DCO, 45 ... Program memory, 46 ... Timing generation circuit.

Claims (4)

[Claims] 1. An instructing means for instructing the generation of a musical tone and one independent system, wherein a plurality of musical tones instructed by the instructing means are assigned to channels and the plurality of musical tones are time-divisionally processed. And an assignment output means for outputting a musical tone waveform generating means for generating a tone waveform of each tone, and an envelope of each tone. An envelope waveform generating means for generating a waveform, a synthesizing means for synthesizing the musical tone waveform generated by the musical tone waveform generating means with the envelope waveform generated by the envelope waveform generating means, and a musical tone synthesized by this synthesizing means. A sound source device comprising: a supply unit that supplies the allocation output unit. 2. The sound source device according to claim 1, wherein the respective systems are not synchronized with each other. 3. The sound source device according to claim 1, wherein each of the systems is operated by a different system clock signal. 4. The sound source device according to claim 1, wherein the instructing means is a computer, and the sound source device excluding the instructing means is attached to and detached from the computer.