Yamaha Corporation

Masaki Kudo

Tokio Shirakawa

Shizuhiko Kawai

Hideo Suzuki

Shinya Sakurada

Harumichi Hotta

Kyoko Ohno

Kozo Tokuda

Tokio Ogi

Masaru Aiso

Yasushi Kurakake

Tsutomu Yanase

Akira Iizuka

Tetsuji Ichiki

Hideaki Shimaya

Tasuya Nonaka

In a control system of a digital mixer, first class devices are connected via a first class bus, and second class devices are connected to each first class device via a second class bus. The number of first class devices, which require a specific function for adding source and destination addresses to data, can be reduced by the number of the second class devices. Moreover, the second class device which does not require the specific function for adding source and destination addresses to data input/output operations is cheaper than the first class device, resulting in the implementation of simplified configuration and reduced production costs.

Control system and communication system for digital mixer

There is provided an electronic keyboard musical instrument that gives the performance feeling closer to that given by an acoustic piano and enables techniques of expression closer to those used when playing the acoustic piano. Touch information is generated based on first information output when an ON event of a first (deep) SW of a switch section occurs, and a tone generator section generates a musical tone according to the touch. When an OFF event of a third (shallow) SW of the switch section occurs during key release, the musical tone being generated is progressively damped, and at the same time a musical tone having a predetermined characteristic is generated. The OFF event of the third SW is made equivalent to a damper-leaving position in a key stroke of an acoustic piano keyboard.

Electronic keyboard musical instrument

A bus system interconnects a plurality of devices of various categories constituting an electronic music instrument apparatus for exchanging signals among the devices having unique addresses. The bus system has a serial clock line for transmission of a clock signal, and a serial data line for transfer of a data signal from a source device to a destination device in synchronization with the clock signal. The source device operates as a master to commence a communicating session such as to send the clock signal to the serial clock line and to send the data signal to the serial data line in synchronization with the clock signal. The destination device operates as a slave so as to receive the data signal based on the clock signal. The source device formulates the data signal containing a unique address specifying the destination device such that the destination device can receive the data signal exclusively from the source device. The unique address contains category information designating a category to which the destination device belongs and a sub-address specifying the destination device in the designated category.

Bi-directional serial bus system for constructing electronic musical instrument

In a sound source apparatus, a central processing unit is integrated in a semiconductor chip and operates in response to a primary operating clock signal for creating a control message. A tone generating unit is integrated in the same semiconductor chip and operates in response to a secondary operating clock signal for generating a musical tone according to the control message. A master clock generator generates a master clock signal having a desired frequency selected from a plurality of frequencies. A mode changer designates one of a first mode and a second mode corresponding to different operating speeds. A clock generator is provided for variably frequency-dividing the master clock signal to generate the primary operating clock signal and the secondary operating clock signal. The clock generator is responsive to the mode changer for changing a frequency ratio of the primary operating clock signal to the secondary operating clock signal between the first mode and the second mode. An external memory is provided separately from the semiconductor chip for storing information required for generation of the musical tone. A memory controller is provided for allotting a primary time slot to the central processing unit and a secondary time slot to the tone generating unit such as to optimize access to the external memory shared by the central processing unit and the tone generating unit. A cache memory is provided to speed up operation of the central processing unit.

Sound source chip having variable clock to optimize external memory

A control circuit is integrated in a semiconductor chip for controlling operation of an electronic musical instrument according to a custom program stored in an external memory so as to generate a musical tone. In the control circuit, an internal memory is formed in the semiconductor chip separately from the external memory for permanently storing a common program which is dedicated to synthesis of the musical tone while the custom program stored in the external memory is customized for the operation of the electronic musical instrument. A tone synthesizer is formed in the same semiconductor chip for synthesizing -,he musical tone when the common program is executed. A central processor is formed in the same semiconductor chip integrally with the tone synthesizer and the internal memory for executing the custom program to control the operation of the electronic musical instrument and for executing the common program to effectuate the synthesis of the musical tone to generate the same sequentially in response to the operation of the electronic musical instrument.

Universal microcomputer chip for electronic musical machine

An electronic musical instrument has a waveform memory and a tone generator. The waveform memory has a plurality of storage areas, each of which is capable of storing a fixed bit-width data. In the case where the bit-width of the waveform data corresponding to a musical tone waveform is different from the bit-width of the data which can be stored in each storage area, the whole waveform data corresponding to the musical tone waveform are stored in the waveform memory so as not to allow the generation of empty areas which store no data. The waveform data may be divided if necessary and the divided parts of the waveform data are stored in some storage areas of the waveform memory. The tone generator reads out the data corresponding to a desired musical tone which is to be generated and which are stored in the waveform memory, and determines the waveform data from the read out data based on the bit-width of the waveform data of the desired musical tone, and generates the musical tone based on the determined waveform data.

Electronic musical instrument having a waveform memory for storing

A controller is arranged as a sub control unit between a CPU as a main control unit and a tone generator system. The main control unit outputs command data having a standard format as an instruction signal. The sub control unit generates and outputs instruction data as an instruction signal in a format according to the type of tone generator system on the basis of the command data. The tone generator system executes generation of a tone signal and processing associated with generation of the tone signal in accordance with the instruction data. The CPU can efficiently control tone generator systems of different types. Data transfer between the CPU and a plurality of tone generator systems of different types can be highly efficiently performed, and the processing load on the CPU can be reduced.

Electronic musical instrument including tone generator controller

Reading of a waveform memory is controlled and one of different processing is performed depending upon which of a first mode and a second mode has been designated. When the first mode has been designated, an interpolation operation is performed on the basis of plural sample value data read from the waveform memory by using a predetermined number of processing time slots and a resulting one waveform sample value data is produced. When the second mode, has been designated, a processing for producing one waveform sample value data is performed on the basis of one sample value data read from the waveform memory by using one processing time slot. By using a predetermined plural number of processing time slots, one waveform sample value data produced with a high accuracy in the first mode whereas plural waveform sample value data are produced in the second mode whereby generation of a waveform can be performed efficiently by properly utilizing the mode.

Waveform generation device capable of reading waveform memory in plural

An addition section and a memory section for storing data to be inputted to the addition section are provided. A processing section variably performs a logical processing on output data of the memory section in accordance with a control signal and gives the data to the addition section. A control section controls introduction of data to the memory section and supply of the control signal to the processing section in correspondence to respective desired operations so that plural kinds of operations for tone signal generation may be respectively performed. With this arrangement, the addition section can be shared for various kinds of operations for the tone signal generation. Consequently, operation circuits for performing the various operations are integrated, so as to realize a substantial reduction of circuitry construction.

Tone signal generating device

An acoustic signal processing apparatus comprising infinite impulse response type digital filters and phase control device. The filters receive an acoustic signal. Outputs from the filters are synthesized to generate an output signal. The phase control device controls the phase of the output signals so as to cause limit cycle noise components generated by the filters to cancel each other on synthesizing.

Acoustic signal processing apparatus

A tone generated by a tone source is converted to an electric signal and this electric signal is sampled. The converted digital data are stored in a first memory, and parts which are to become a initial portion and a repeating portion of a waveform of the tone source are extracted from the data in the first memory. Next, the attack end sample AES, which is the end of the initial portion, is determined. and a loop-in point (a point at which transfer from the initial portion to the repeating portion is accomplished) LIP which is in agreement with this attack end sample is obtained. Then, the loop end sample LES, which is the end of the repeating portion, is determined, and a loop start point (beginning of the repeating portion) LSP which is in agreement with this loop end sample LES is obtained. Alternatively, the beginning of the repeating portion is determined, and an end of the repeating portion or an end of the initial portion which is in agreement with this is obtained. Data are read out from the first memory in accordance with addresses corresponding to the beginning and the end of the repeating part obtained in the above manner, and these are written to a second memory. At this time, in the case in which addresses necessary for interpolation processing are obtained, reading and writing processes are carried out in accordance with the addresses used for interpolation.

Musical tone generating apparatus

Two tone generators having different tone generation systems, e.g., PCM type and FM type, are provided. There are tone generation modes designating combination of tone generation in these tone generators and one can be selected from among them. There are, for example, a simple mixing mode, a delay mode in which start of tone generation in one tone generator is delayed from that in the other and a crossfade mode in which a tone signal is generated first in one tone generator and tone generation is switched to the other tone generator and envelope levels of output tone signals of the two tone generators are crossfaded during a switching period. Delay time in the delay mode and switching time in the crossfade mode can be variably controlled in accordance with a key scaling and/or other factors. A tone may be generated at a sampling frequency synchronized with a pitch in one tone generator and at a sampling frequency which is not synchronized with the pitch in the other tone generator. A phase of one cycle may be divided into plural sections and a complex waveform can be generated by converting the phase address signal in accordance with a function peculiar to each phase section and accessing a waveform memory with the converted address signal.

Electronic musical instrument having plural different tone generators

An envelope shape generator generates envelope shape data for controlling a tone signal in the form of data in decibel representation. In performing a rapid attenuation control called 'forcing damp' during attenuation of the envelope shape data generated by the envelope shape generator, the envelope shape data in decibel representation is rapidly attenuated with such a characteristic that inclination of attenuation becomes increasingly steeper. This is advantageous because inclination of a rapidly attenuating portion is modified to a substantially uniform inclination when the envelope shape data is converted to data in linear representation. There are also provided a detection circuit for detecting that the level of the envelope shape has dropped below a predetermined level corresponding to a minimum level at which a tone waveshape can be effectively represented and a circuit for rapidly attenuating the envelope shape in response to this detection. This contributes to elimination of noise.

Envelope shape generator for tone signal control

A musical tone generating apparatus utilizing a data compression method. A musical tone is sampled and is converted into waveform data. These waveform data are compressed into compressed data by a linear predictive coding method and further by a differential quantization method. The number of bits of each of the compressed data is thus significantly smaller than that of the waveform data. Thereafter, a memory stores the thus compressed data corresponding to an attack portion of the tone and a selected part of a sustain portion of the tone. Hence, it is possible to remarkably reduce the memory storage. When generating a musical tone, the memory reads out the compressed data of the attack portion and thereafter repeatedly reads out the compressed data of the selected part. The read-out compressed data are sequentially decoded into the original digital data. Thus, the whole waveform of the musical tone is reproduced.

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Hamamatsu, Japan

Masaki Kudo