JP4070347B2 - Music signal generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of keyboard electronic musical instruments, and more particularly relates to a musical sound signal generator provided in an electronic musical instrument.
[0002]
[Prior art]
The keyboard electronic musical instrument generates tone signal waveform data (digital signal) corresponding to the tone color selected by the performer and the key (key) operated by the performer, and is composed of a DAC, an amplifier, a speaker, and the like. It is equipped with a musical tone signal generator that supplies the audio output system.
[0003]
A conventional musical tone signal generator has a configuration shown in FIG. 4, for example.
The external waveform memory is a sample of digital data obtained by sampling a musical sound waveform that differs for each musical instrument (ie, timbre) and each pitch (key number) for each set sampling timing, for example, piano, guitar, organ, etc. Stores waveform data.
[0004]
A waveform start channel, an F number accumulator, an envelope generator, a sample interpolation multiplier table, a latch, an adder circuit, a multiplier circuit, an adder, and the like constitute one waveform generation channel, and a plurality of such waveform generation channels (usually 32 Channel or 64 channels).
[0005]
The tone selected by the performer (for example, corresponding to musical instruments such as piano, guitar, organ, etc.) and key event information (key number, velocity, etc.) related to key on / off operated by the performer are scanned by means of scanning means not shown. The detected CPU, not shown, selects one of the waveform generation channels, and links (assigns) the tone color and key event information to the waveform generation channel (channel number).
[0006]
With respect to the assigned waveform generation channel, the sample waveform data at the address specified by the waveform start address and the F number accumulator is read and held in the latch at every read sampling period, and the data from the latch is F. The interpolation value output from the sample interpolation multiplier table is multiplied by the interpolation value from the number accumulator and input to the adder. The data from the adder is multiplied by the envelope data from the envelope generator and input to the sequence accumulator.
[0007]
The musical tone signal waveform data generated in each waveform generation channel and input to the sequence accumulator in this way is sequence-accumulated, supplied to the L and R audio output systems, and output as audio.
The timing chart for reading the sample waveform data by each waveform generation channel is as shown in FIG. 5, and all the sample waveform data required during one sampling period at the time of reading is all within one reading sampling period. This is a method of reading from an external waveform memory. In the illustrated example, the read sampling period is 44.1 kHz, the number of channels is 64, and two sample waveform data are read for each channel.
[0008]
As shown in FIG. 4 by enclosing with a broken line, a 2-sample memory is added to store the previously read sample waveform data (previous data), and both the sample waveform data read this time and the previous data are stored. Some have used sample point interpolation values with high accuracy. However, even in the method using the previous data, there is no change in reading new sample waveform data for all assigned channels at every read sampling period.
[0009]
These conventional musical tone signal generators have a simple circuit configuration, high accuracy, and are reasonably efficient.
[0010]
[Problems to be solved by the invention]
However, there was a problem in the marketability (supply amount and price) of the external waveform memory.
The external waveform memory used by conventional musical tone signal generators is a semiconductor memory capable of high-speed random access such as ROM, RAM (D-RAM, S-RAM), flash memory, etc. However, in recent years, the capacity increase curve of these semiconductor memories has reached its peak (capacity increase cannot be expected as in the past).
[0011]
On the other hand, in musical tone signal generators, users of electronic musical instruments tend to demand more realistic sounds and sounds with a wider dynamic range. To meet such demands, a larger amount of sample waveform data Therefore, the capacity of the external waveform memory is increasing at a speed exceeding the increase in the capacity of the semiconductor memory. For this reason, in recent musical tone signal generators, it is becoming common to use a plurality of 64-megabit mask ROMs as external waveform memories.
[0012]
The reason for adopting a 64-megabit mask ROM is that, at present, the lowest price per bit is a mask ROM, and the largest capacity of the mask ROM is the most advanced because it is 64 megabits. .
However, the technological advancement of flash memory is significant, and the bit unit price of flash memory is now more than twice that of mask ROM. However, flash memory may be cheaper in the future.
[0013]
The mask ROM is not suitable for recycling because the contents cannot be rewritten, but the flash memory is excellent in recyclability because it can be rewritten any number of times. Widely adopted.
[0014]
By the way, the flash memory has a structure in which random access is possible at medium speed (about 100 ns) and a small number of small flash memories (cells) that can be accessed at high speed (50 ns or less) as in the mask ROM (cell structure). Flash memory), it takes quite a long time to specify a cell (about 10 μs), but once a cell is specified, the memory content in that cell is 2 times faster than the type described above. There are types.
[0015]
In the present invention, as in the above-described cell structure flash memory, random access takes time, but continuous reading after a certain cell (or area) is designated is a semiconductor memory or mechanical memory that can be accessed at a very high speed. An object of the present invention is to provide a musical tone signal generator suitable for using the apparatus as waveform storage means (storage means for storing sample waveform data).
[0016]
[Means for Solving the Problems and Effects of the Invention]
A musical tone signal generator according to claim 1 for solving the above-mentioned problem is provided with waveform storage means for storing musical tone waveform sample waveform data specified by tone color and key number, and assigned tone color and key number. A musical tone signal generator comprising: a plurality of waveform generation channels for acquiring the sample waveform data from the waveform storage means and performing arithmetic processing on the acquired sample waveform data for each readout sampling period to generate musical signal waveform data In the apparatus, each of the waveform generation channels includes the sample waveform data required for generating at least M times of the musical tone signal waveform data from the waveform storage means at a rate of once every M (M is a plurality) of the read sampling periods. (N) acquisition waveform storage means for acquiring and storing the acquisition waveform storage means for each readout sampling period. The read from device sample waveform data by performing arithmetic processing and generating the musical sound signal waveform data.
[0017]
Each waveform generation channel of the musical tone signal generating device according to claim 1 is a sample required for generating at least M musical tone signal waveform data from the waveform storage means at a rate of once every M sampling cycles (M is a plurality). Waveform data (N pieces) is acquired and stored in the acquired waveform storage means. Then, musical tone signal waveform data is generated by performing arithmetic processing on the sample waveform data read from the acquired waveform storage means for each reading sampling period.
[0018]
That is, N sample waveform data required for generating the musical tone signal waveform data for the M reading sampling cycles is pre-read and stored, and then the sample waveform data is acquired from the waveform storage means until The musical tone signal waveform data is generated using the pre-read sample waveform data.
[0019]
For example, if there are 64 waveform generation channels and M = 64, a certain waveform generation channel reads and stores N (for example, N = 64 × 2) sample waveform data in a certain readout sampling period. is there. In this way, all waveform generation channels can capture and store sample waveform data for 64 readout sampling periods in 64 readout sampling periods.
[0020]
The time given to one waveform generation channel for one reading is one readout sampling period, which is extremely long compared to the conventional reading time (time obtained by dividing one readout sampling period by the number of waveform generation channels). Therefore, even in a memory that takes time to designate a cell (area) such as the above-described cell structure flash memory, a large number of sample waveform data can be read by designating the cell.
[0021]
Therefore, like a cell structure flash memory, random access takes time, but a semiconductor memory (or mechanical storage device) that can be accessed at a very high speed for continuous reading after a certain cell (area) is designated, It is suitable for use as waveform storage means.
[0022]
A configuration may be adopted in which sample waveform data for a plurality of waveform generation channels is captured and stored in one readout sampling period.
In order to pre-read a large number of sample waveform data in this way and generate musical tone signal waveform data using this, it is preferable that the pre-read sample waveform data is continuous in the sampling order. That is, as described in claim 2, in the musical sound signal generator according to claim 1, the N pieces of sample waveform data stored in each of the acquired waveform storage means may be continuous in the sampling order. .
[0023]
A musical tone signal generator according to claim 3 is suitable for handling sample waveform data that is continuous in such a sampling order.
The musical tone signal generator according to claim 3 is the musical tone signal generator according to claim 1 or 2, based on the tone color set by the tone color setting means operated by the performer and the key number of the key that is turned on. Allocating means for allocating the address of the waveform storage means determined to any one of the waveform generating channels, and the waveform generating channel is stored in N addresses stored in consecutive addresses from the address allocated by the allocating means. The sample waveform data is read out and stored in the acquired waveform storage means.
[0024]
In this musical tone signal generator, the assigning means assigns the address of the waveform storage means determined based on the tone color set by the tone color setting means operated by the performer and the key number of the on-operated key to any of the waveform generation channels. The waveform generation channel reads the N sample waveform data stored at successive addresses from the address assigned by the assigning means and stores it in the acquired waveform storage means.
[0025]
When the sample waveform data is stored in the waveform storage means, if the addresses are given according to the sampling order, the sample waveform data stored in the consecutive addresses from the assigned address is read out, and the sample waveform data is continuously recorded in the sampling order. Sample waveform data can be acquired.
[0026]
The musical tone signal generator according to claim 4 is the musical tone signal generator according to any one of claims 1 to 3, wherein the waveform generating channel is shared between the waveform storage means and the acquired waveform storage means. In-first-out buffer memory is provided, and the acquired waveform storage means reads and stores the N pieces of sample waveform data read from the waveform storage means and stored in the buffer memory. The timing for storing the sample waveform data in the storage means can be set to an arbitrary period of one readout sampling period.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be specifically described with reference to the drawings.
[0028]
[Example 1]
FIG. 1 is a block diagram illustrating the configuration of a musical tone signal generator 10 according to the present embodiment. The musical tone signal generator 10 is a part of a keyboard-type electronic musical instrument. The keyboard-type electronic musical instrument includes a keyboard having a plurality of keys, a tone selection switch (tone setting means) for setting a tone, and a tone. Assigning device (assignment means) etc. (all not shown) that assigns the generation of musical tone signal waveform data corresponding to the tone set by the selection switch and the key number of the key that is turned on to any of the waveform generation channels I have.
[0029]
As shown in FIG. 1, the musical tone signal generator 10 of the present embodiment includes an external waveform memory 20 storing sample waveform data and musical tone signal waveform data (digital) based on the sample waveform data read from the external waveform memory 20. A waveform generator 40 for generating a signal). The external waveform memory 20 corresponding to the waveform storage means is a NAND cell structure flash memory, and in this embodiment, TC58V64FT made by Toshiba is used. This TC58V64FT takes about 10 μs for cell selection and a serial read cycle for continuous address reading in the same cell is about 50 ns. Further, the waveform generator 40 is a single LSI, and will be described later in detail. Each of the waveform generators 40 includes 64 tone generation channels for generating a sample waveform of one tone.
[0030]
An assignment memory 46 of the waveform generator 40 is a RAM and stores assignment information (for 64 channels) for each channel. Assignment information corresponding to all timbres and key numbers is stored in the ROM of the assigning device, and the assigning device reads the ROM based on the timbre set by the timbre selection switch and the key number of the key that is turned on. Is read from and written to the assignment memory 46.
[0031]
The assignment information for one channel consists of a key number, its on / off information, waveform start address, L-side and R-side panning coefficients, attack, decay and release envelope data, loudness data, and the like, and is in accordance with known techniques.
[0032]
The waveform start address 48 is a register memory and is provided for the number of channels (64 in this embodiment). Each waveform start address 48 stores one waveform start address data of assignment information. The waveform start address data (A0 to A31, 32 bits) of the waveform start address 48 is sent to the adder ADD1.
[0033]
Similarly to the waveform start address 48, the F number accumulator 50 is provided for the number of channels (64 in this embodiment). The F number accumulator 50 receives the F number and key on / off information corresponding to the key number. Of the output of the F number accumulator 50, 24 bits A0 to A23 corresponding to the integer part of the F number are sent to the adder ADD1, added to the waveform start address data, and used as an external waveform memory address controller as a waveform read address. 58, and input from the external waveform memory address controller 58 to the external waveform memory 20. Since the I / O port of the external waveform memory 20 is 8 bits, it is actually input to the external waveform memory 20 by dividing it into 4 times every 8 bits.
[0034]
The sample waveform data stored at the address specified by the waveform read address is read and stored in the FIFORAM 60 which is a first-in first-out buffer memory. The FIFO RAM 60 has two storage areas A and B, and can store 128 sample waveform data in each storage area. The selection of the A area and the B area of the FIFO RAM 60 follows the area switching signal from the cycle tail transfer address generator 57. The cycle stale transfer address generator 57 is a kind of counter, repeatedly generates 13-bit values in ascending order from 0, and outputs an area switching signal every time 0 is reset.
[0035]
The 7 bits A0 to A6 of the F number accumulator 50 are sent to the internal waveform memory address controller 54. The internal waveform memory address controller 54 also receives a 13-bit signal from the cycle stale transfer address generator 57. The internal waveform memory address controller 54, based on the 7 bits A0 to A6 of the F number accumulator 50 and the 13 bits from the cycle tail transfer address generator 57, for example, 128 sample waveform data from the first to 128. A 13-bit signal consisting of 7 bits for instructing the eyes in ascending order and 6 bits for specifying 64 waveform generation channels is an RAM, and is an address designation signal for the internal waveform memory 56 corresponding to the acquired waveform storage means. Is generated and output.
[0036]
Similar to the waveform start address 48 and F number accumulator 50, the internal waveform memory 56 is provided for the number of channels (in this embodiment, 64), and the sample waveform data read from the FIFO RAM 60 is stored in the internal waveform memory address controller 54. Is stored in the address designated by the address designation signal from. The stored sample waveform data is periodically sent (according to the read sampling period) to the latches L1 to L4 (one sample waveform data each).
[0037]
Multipliers MLT1 to MLT4 are respectively arranged on the output side of the latches L1 to L4. The values (sample waveform data) latched in the latches L1 to L4 and the sample interpolation multiplier table 52 are arranged in the multipliers MLT1 to MLT4. The interpolation multiplier from is input. The interpolation multiplier is a value selected in the sample interpolation multiplier table 52 corresponding to 4-bit data A-4 to A-1 corresponding to the decimal part of the F number output from the F number accumulator 50. Yes, each of the multipliers MLT1 to MLT4 multiplies the sample waveform data by an interpolation multiplier (interpolates).
[0038]
The interpolated sample waveform data is added in the adder 62 and sent to the multiplier MLT 5 as added waveform data. The multiplier MLT5 receives envelope data from the envelope generator 63 and multiplies the added waveform data by the envelope data to produce musical tone signal waveform data. The envelope data multiplied here is based on the attack, decay, and release envelope data supplied from the assignment memory 46 to the envelope generator 63.
[0039]
The output (music signal waveform data) of the multiplier MLT5 is input to the series accumulation circuit 64, where the accumulation processing of the music signal waveform data for all channels (64 channels in this embodiment) is performed. The accumulated data is sent from the left output terminal L to the digital analog converter (D / A) 66L of the left output system, and from the right output terminal R to the digital analog converter (D / A) 66R of the right output system. Are converted into analog signals, amplified by an amplifier (not shown), and output from a speaker (not shown).
[0040]
In the case of the present embodiment, there are 64 waveform start addresses 48, F number accumulators 50, internal waveform memory 56 and envelope generator 63, and the assignment information for one channel of assignment memory 46 is as follows. The waveform start address 48, the F number accumulator 50, the internal waveform memory 56, and the envelope generator 63 are associated with each other to form one set, and each set is operated in a time-sharing manner once per read sampling period. (However, the data storage operation of the internal waveform memory 56 is not performed once per reading sampling period.) Thus, 64 tone signal waveform data can be generated per reading sampling period. That is, there are 64 waveform generation channels.
[0041]
Next, the operation of storing sample waveform data in the internal waveform memory 56, which is specific to the musical tone signal generator 10 of this embodiment, will be described with reference to FIG.
The readout sampling period for time-sharing the 64 waveform generation channels described above is 44.1 kHz (1 period = 22.67 μs), and this is equally divided into 64 to set channel calculation time slots of 0 to 63. .
[0042]
In the waveform read time slot for reading sample waveform data from the external waveform memory 20, the first half 11.3 μs of one read sampling period is allocated to the cell selection time and the second half is allocated to the data read time as shown in the figure.
The master clock is 22.58 MHz. When one read sampling period starts, a waveform read address for cell selection in the external waveform memory 20 is output from the external waveform memory address controller 58 to the external waveform memory 20. Since the address input port of the external waveform memory 20 is 8 bits, the external waveform memory address controller 58 divides the waveform read address (32 bits) into 8 bits (A0 to A7, A8 to A15, A16 to A23, A24 to A31), and sent to the external waveform memory 20 for each cycle of the master clock. Each 8-bit data is latched by the address latch clock and taken into the external waveform memory 20. The time required so far is four master clock cycles (177 ns).
[0043]
The cell of the external waveform memory 20 is designated by the waveform read address, and the data of the selected cell is transferred to the output register within the external waveform memory 20. In the present embodiment, each cell stores 1-byte sample waveform data at 128 addresses continuous from the start address of the cell, and the 128 sample waveform data are transferred to a register. As described above, since the time required for cell selection in the external waveform memory 20 is about 10 μs, cell selection in the external waveform memory 20 (within the external waveform memory 20 takes place in 11.3 μs from 0 to 31 channel calculation time slots). Data transfer) is completed. The address order of the sample waveform data in the cell is the sampling order. In other words, if the sample waveform data is read in the order of addresses, the order of sampling is directly applied.
[0044]
At the start of 32 slots, the waveform read clock for the external waveform memory 20 falls. Thereafter, the waveform readout clock repeats falling every two cycles of the master clock, and returns to the high level at the end of 63 channel operation time slots (at the end of one readout sampling cycle and at the start of the next readout sampling cycle). That is, the waveform read clock maintains a high level in the first half of the read sampling period, and falls every two periods of the master clock in the second half.
[0045]
Due to the fall of the waveform readout clock, 8-bit data (that is, one sample waveform data) at the head address in the cell is output from the output register of the external waveform memory 20 and stored in the FIFO RAM 60. The Then, every time the waveform reading clock falls, sample waveform data at addresses consecutive from the head address is read one by one and stored in the FIFO RAM 60. By repeating such an operation, 128 sample waveform data from the cell selected by the read / read address can be stored in the FIFO RAM 60.
[0046]
As shown in the figure, the serial read time of the external waveform memory 20 is 66.3 ns, which corresponds to the fall from the rise of the waveform read clock, and therefore, between 11.3 μs from 32 to 63 channel operation time slots. In addition, 128 sample waveform data for a certain waveform generation channel can be stored in the FIFO RAM 60.
[0047]
Since the 128 sample waveform data read out from the external waveform memory 20 and stored in the FIFO RAM 60 are stored in consecutive addresses in the same cell of the external waveform memory 20 as described above, as long as the cell selection is completed, the external waveform is stored. Reading data from the memory 20 can be performed in a very short time.
[0048]
The sample waveform data stored in the FIFO RAM 60 is sent to and stored in the internal waveform memory 56 in the next readout sampling period.
Since the FIFORAM 60 has two storage areas A and B as described above, if, for example, 128 sample waveform data are stored in the A area in a certain read sampling period, the sample of the A area is acquired in the next read sampling period. The waveform data is output to the internal waveform memory 56, and new sample waveform data from the external waveform memory 20 is stored in the B area. In the next readout sampling period, the data is output from the B area to the internal waveform memory 56 and stored in the sample waveform data A area from the external waveform memory 20. As described above, since data is stored in one of the two areas A and B and output from the other, 128 sample waveform data are stored for each readout sampling period, and 128 sample waveform data are also stored in the internal waveform memory 56. Can output.
[0049]
Therefore, the waveform generator 40 of the musical tone signal generator 10 has 128 sample waveform data for one waveform generation channel per read sampling period, except for the read sampling period immediately after the initial state (FIFORAM 60 is empty). Can be acquired from the external waveform memory 20 and stored.
[0050]
At each readout sampling period, each waveform generation channel reads four consecutive samples from 128 sample waveform data stored in the internal waveform memory 56, and stores them in the latches L1 to L4, respectively. The interpolation processing and the addition processing are performed as described above. Note that the four sample waveform data sent to the latches L1 to L4 for each readout sampling period are not different each time. For example, if the current data is the fourth data of 0 to 3, the next time is the 4th data of 1 to 4, Next, 4 data Nos. 2 to 5 are set to 4 data obtained by shifting the sampling order (that is, the address order in the external waveform memory 20) by one.
[0051]
Therefore, since the number of sample waveform data required until the next sample waveform data acquisition opportunity (after 64 reading sampling cycles) is 64 + 3 = 67, at least 67 data is acquired in one acquisition opportunity. And storing it in the internal waveform memory 56 is sufficient. In this embodiment, one sample waveform is generated using four sample waveform data (the 4-point method). However, if the 2-point method is used, 64 + 1 = 65 data is taken into the internal waveform memory 56. It will be good. As in the present embodiment, 128 sample waveform data may not be stored in the internal waveform memory 56 in one readout sampling period, and a minimum necessary number of sample waveform data may be stored in the internal waveform memory 56. . By doing so, the data read time can be shortened.
[0052]
As described above, each waveform generation channel has 128 samples (67 pieces of sample waveform data required for generating 64 musical tone signal waveform data (67 pieces) from the external waveform memory 20 at a rate of once every 64 reading sampling periods. ) Is obtained, stored in the internal waveform memory 56, and interpolation processing (multiplier MLT1) is performed on the four sample waveform data output from the internal waveform memory 56 to the latches L1 to L4 at each read sampling period. ~ 4), the tone signal waveform data is generated by performing the addition process (adder 62) and the envelope process (multiplier MLT5), so that random access takes time, but after a certain cell (area) is specified Is suitable for using a semiconductor memory (cell structure flash memory) that can be accessed at a very high speed as the external waveform memory 20. That.
[0053]
In the cells of the external waveform memory 20, the sample waveform data that is continuous in the sampling order is stored in the continuous addresses according to the order, which is suitable for the above-described continuous reading.
Also, since the continuously read sample waveform data is temporarily stored in one storage area of the FIFO RAM 60 and stored in the internal waveform memory 56 in the next read sampling cycle, the timing of storing the sample waveform data in the internal waveform memory 56 Can be set to an arbitrary period of one readout sampling period, and overlap with the timing of output from the internal waveform memory 56 to the latches L1 to L4 can be avoided.
[0054]
[Example 2]
The first embodiment is an example in which a cell structure flash memory of about 10 μs is used for cell selection. In the second embodiment, a cell structure memory that requires a shorter time (for example, about 300 ns) for cell selection is used. . Since the hardware configuration is the same as that of the first embodiment, illustration and description are omitted, and the reference numerals of the first embodiment are cited.
[0055]
As shown in FIG. 3, also in the second embodiment, a waveform read address is sent to the external waveform memory 20 in order to designate a cell of the external waveform memory 20 simultaneously with the start of the read sampling period as in the first embodiment. Cell selection (transferring cell data to the output register) in the external waveform memory 20 is completed in 354 ns (one channel operation time slot).
[0056]
During the time slot (for example, 1 slot) following the channel calculation time slot (for example, 0 slot) in which cell selection has been performed, the waveform read clock for the external waveform memory 20 falls at the start of that slot, and thereafter the master clock It falls a total of 4 times every 2 cycles. And like the case of Example 1,
Due to the fall of the waveform readout clock, one sample waveform data is sent from the external waveform memory 20 to the FIFO RAM 60 and stored therein.
[0057]
In this way, four sample waveform data are read out in a time corresponding to two slots of the channel calculation time slot and stored in the A area or B area of the FIFO RAM 60. The sample waveform data stored in the FIFO RAM 60 is transferred to and stored in the internal waveform memory 56 during a period in which data is read from the next external waveform memory 20 (a period corresponding to the next two time slots). Thus, the external waveform memory is used by alternately using the A and B areas, for example, storing in the A area in 0 to 1 slot and storing in the B area and sending out from the A area in the subsequent 2 to 3 slots. Reading from the memory 20 and storing in the internal waveform memory 56 can be executed without delay.
[0058]
In this embodiment, 4 sample waveform data per channel can be read from the external waveform memory 20 for 32 channels per read sampling period. Therefore, in order to read four sample waveform data for all 64 channels, two read sampling periods are required (each waveform generation channel acquires sample waveform data once every two periods).
[0059]
For this reason, in this embodiment, a method (two-point method) that uses two sample waveform data for generating one musical tone signal waveform data is adopted. Compared to the 4-point method used in the first embodiment, the accuracy of the musical tone signal waveform data is somewhat inferior, but there is no practical problem.
[0060]
As in this example, when cell selection can be performed in a short time, sample waveform data for a plurality of channels can be read from the external waveform memory 20 and stored in one readout sampling period. In addition, the apparatus of this embodiment can achieve the same effects as those of the first embodiment.
[0061]
Although the embodiments of the present invention have been described according to the two examples, the present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various ways without departing from the gist of the present invention. .
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a musical sound signal generating device according to a first embodiment.
FIG. 2 is a time chart for reading sample waveform data in the musical tone signal generating apparatus according to the first embodiment;
FIG. 3 is a time chart for reading sample waveform data in the musical tone signal generating apparatus according to the second embodiment;
FIG. 4 is a block diagram illustrating a configuration of a conventional musical tone signal generator.
FIG. 5 is a time chart for reading sample waveform data in a conventional musical tone signal generator.
[Explanation of symbols]
10 ... Music signal generator
20 ... External waveform memory (waveform storage means)
40 ... Waveform generator
46 ... Assignment memory
48 ... Waveform start address
50 ... F number accumulator
52 ... Sample interpolation multiplier table
54 ... Internal waveform memory address controller
56. Internal waveform memory (acquisition waveform storage means)
57 ... Cycle stale transfer address generator
58 ... External waveform memory address controller
60 ... FIFORAM (buffer memory)
62 ... Adder
63 ... Envelope generator
64: Series accumulation circuit

Claims (4)

Waveform storage means for storing musical tone waveform sample waveform data specified by tone color and key number, and acquiring the sample waveform data from the waveform storage means based on the assigned tone color and key number, and reading sampling period In a musical sound signal generating apparatus comprising a plurality of waveform generation channels for generating musical signal waveform data by performing arithmetic processing on the acquired sample waveform data every time,
Each of the waveform generation channels includes the sample waveform data (N pieces) required for generating at least M times of the musical tone signal waveform data from the waveform storage means at a rate of once every M (M is a plurality) of the read sampling periods. ) Is acquired and stored, and the musical tone signal waveform data is generated by performing arithmetic processing on the sample waveform data read from the acquired waveform storage means at each readout sampling period. A featured tone signal generator. In the musical tone signal generator according to claim 1,
The musical tone signal generator according to claim 1, wherein the N pieces of sample waveform data stored in each of the acquired waveform storage means are continuous in the sampling order. In the musical tone signal generator according to claim 1 or 2,
Allocating means for allocating an address of the waveform storage means determined based on a timbre set by a timbre setting means operated by a performer and a key number of an on-operated key to any one of the waveform generation channels;
The waveform generation channel reads out the N pieces of sample waveform data stored in consecutive addresses from the address assigned by the assigning means and stores them in the acquired waveform storage means. apparatus. In the musical tone signal generator according to any one of claims 1 to 3,
A first-in first-out buffer memory shared by the waveform generation channels between the waveform storage unit and the acquired waveform storage unit;
The acquired waveform storage means reads and stores the N pieces of sample waveform data read from the waveform storage means and accumulated in the buffer memory.

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