JPH0422274B2 - - Google Patents

Description

[Detailed description of the invention]

(1) Technical Field of the Invention The present invention has a musical tone generator capable of simultaneously producing fewer keys than a plurality of keys, and has a keyboard circuit that detects the on/off state of a key switch in response to key presses and key releases and assigns the keys to channels. It is about the method. (2) Prior art and problems In recent years, electronic musical instruments have had fewer musical tone generators than multiple keys due to the technological development of key switch processing methods, and it is now possible to limit the number of simultaneous polyphonic sounds and collect key press information. A method of obtaining a desired musical tone by transmitting it to a musical tone generator is often used. Conventionally, when these keys were pressed more than the number of simultaneous polyphony, that is, when the number of assigned channels was n, all n keys were used and a new key was pressed, the new key pressed was the same as the previously pressed n keys. No new assignments will be made unless at least one of the keys is released. If the new pressed key is among the n keys counted from the lowest or highest note of the previously pressed n keys, it is assigned. A new key is assigned by erasing the intermediate tones of the previously pressed n keys. The following methods are used. In contrast to these methods for general envelope waveforms, it is difficult to obtain natural percussion-type musical tones by simply applying the above methods to electronic instruments with percussion-type envelopes. There is a problem. In other words, the characteristic of percussion-type musical sounds is that the amplitude attenuates over time from the key pressed, and the amplitude of the first key pressed decreases even though the key is pressed. When the attenuation state is entered or the amplitude reaches "0", the sound generation ends.
If the musical tone generator has already finished generating sound, it would be extremely wasteful to occupy that musical tone generator even though it is not generating sound. Furthermore, since the output amplitude of the musical tone is attenuated the most for the key that was released first, the newly pressed key is more important. However, in the above method, there seems to be a limit to the maximum number of notes that can be produced, in the above method, the desired new key to be pressed cannot be assigned unless it is among the n keys; A phenomenon occurs in which external intermediate tones cannot be assigned. Furthermore, in these cases, a sense of incongruity occurs between the keys that the player desires and actually presses and the musical tones that are being produced. This happens with any waveform envelope, but
This is especially noticeable with percussion type musical tones. (3) Purpose of the Invention The purpose of the present invention is to provide a keyboard circuit which has a musical tone generator capable of simultaneously producing fewer keys than a plurality of keys, detects the on/off state of a key switch in response to a key press or release, and assigns it to a channel. To provide a keyboard circuit assignment method that minimizes the sense of incongruity between keys that are actually pressed and musical tones that are being sounded. (4) Structure of the Invention In order to achieve the above-mentioned object, the keyboard circuit assignment method of the present invention has a musical tone generator capable of simultaneously producing fewer keys than a plurality of keys, and changes the on/off state of a key switch according to key depression and key release. In the keyboard circuit assignment method that detects and assigns to channels, when a new key is pressed more than the number of simultaneous polyphony, the new key is assigned to the channel of the first key released among the keys that are being sounded simultaneously. It has a means for newly allocating key information for a pressed key, and also saves key information of the channel of the key pressed first among the keys of the simultaneous polyphony being pressed in a separately provided save memory. , newly assigning the key information of the new key press to the empty channel,
The present invention is characterized by comprising means for newly allocating the saved key information from the save memory when the number of pressed keys becomes equal to or less than the number of simultaneous pronunciations. (5) Embodiments of the Invention FIG. 1 is a system block diagram of an electronic musical instrument to which the present invention is applied. The system 100 includes a keyboard circuit 14, a key state change detection and assignment device 10 (hereinafter referred to as an assigner), a musical tone frequency generator 31 in charge of musical tone generation, musical tone envelope generators 33-1 and 33-2, a musical waveform generator 35, and an assigner. Various ports 30, 32-1, 32- for interfacing with various devices
Consists of 2,34. In the present invention, the assigner 10 is described as using a central processing unit (hereinafter referred to as CPU), but this does not limit the present invention. Assigner 10
includes a CPU 12, a main clock 11 that drives it, a program memory 16, an event memory 17, an assignment memory 18, a count memory 19,
Backup memory 20, output port (1) 13, input port
(1) Consists of 15 parts. Receiving the driving clock from the main clock 11
The CPU 12 operates according to the program stored in the program memory 16 in internal registers (hereinafter referred to as
A scan code for scanning the keyboard circuit 14 is created in the OD register), and the created scan code is sent to the output port (1) 13 through the bus 101, and the scan code from the output port (1) 13 is transmitted to the output port (1) 13. The input port (1) 15 receives the open/closed state of the key switch in the group of the keyboard circuit 14 corresponding to the
Output data of input port (1) 15 (key open/closed state)
on bus 101. CPU12 is bus 10
an event memory 17 that stores the data placed on 1 and the key information from the previous scan corresponding to each key;
The presence or absence of a change (hereinafter referred to as an event) is checked by comparing the data of the location (area) corresponding to the scan code within. If there is no event, the CPU
12 increments the contents of the OD register and sequentially sends the scanning code to the keyboard circuit 14, which repeatedly scans until an event occurs. If an event occurs, from that point on, operations such as allocation to or release from the assignment memory 18 having the same number of channels as the number of simultaneous polyphony for the key where the event occurred (event processing) are performed. Enter the program to be performed. When an event occurs, it determines (a) whether the key is an OFF-to-ON event, (b) an ON-to-OFF event, and (c) whether the key information for the key is already assigned. The newer and older channels are determined from the counter value of the memory 18, or the counter value of the count memory 19, which stores the newer and older keys as values (hereinafter referred to as count values) when keys are pressed more than the number of simultaneous polyphony, and corresponds to the oldest channel. By forcibly allocating the key information to the channel of the assignment memory 18 to be assigned and checking the contents of the save memory 20 in which the key information previously stored there is saved, the assignment to the assignment memory 18 or the assignment memory can be made. 18. If the contents of the assignment memory 18 change, the necessary information from the contents of the assignment memory 18 is transferred to another block, for example, the output port (2) 30, to the musical tone frequency generator 31 and input via the bus 101. It is transferred to musical tone envelope generators 33-1, 33-2 through output port (1) 32-1 and input/output port (2) 32-2, and to musical tone generator 35 etc. through output port (3) 34. A more detailed explanation will be given later using flowcharts shown in FIGS. 3, 4, and 5. FIG. 2 is a configuration explanatory diagram of an embodiment of the present invention,
A specific circuit example of the keyboard circuit 14 in FIG. 1 is shown. Output port (1) 13 and input port (1) 15 whose blocks have the same numbers as in FIG. 1 are the same as those in FIG. The scan code sent from the OD register of the CPU 12 is latched at the output port (1) 13. In this figure, when a 6-bit scanning code is input, 3-8 decoders 40-1 to 40-
9 to configure a 6-64 decoder to U1
~U10, L1~L10, P1~P4, T1~
A scan pulse (in this figure, a negative logic pulse) is applied to one of several groups of Tn (this is illustrated in the appendix, meaning that the tablet switch scan can also be placed on the same bus). is sent onto the scan line. In addition, decoders 40-2 to 40-9
8 connected to each output and input port (1) 15
As the intersection of the buses (0 to 7) in the book is drawn in the circle 111, it is composed of a switch and a diode, and if the switch is open, even if the scanning pulse is coming (it will go "L"). ) is not connected, so
The eight buses are pulled up by pull-up resistors (R ₀ to R ₇ ), and when "H" is input to the input port (1) 15 and the switch is closed, the buses (0 to 7) whose switches are closed are It is coupled to the scan line by a diode and a switch, and the bus on switch closure is "L". Then, open the switch → “H”,
Switch closed → “L” signal is input port (1) 1
5 and is read into the CPU 12 to determine whether the switch is open or closed, that is, an event. Next, event memory 1 used in the present invention
7. The configurations of the assignment memory 18, count memory 19, and save memory 20 will be described. Before that, the system of the present invention has an upper keyboard 61 as an embodiment.
Assume that the keyboard has three keys: a key, a lower keyboard with 61 keys, and a foot keyboard with 25 keys. Furthermore, although the memory is configured by using an 8-bit CPU, which is popular as the CPU 12, this does not limit the present invention. Table 1 shows the contents of the event memory 17. The upper, lower, and foot keyboards are grouped into groups of 6 to 7 keys each, and the upper keyboard has 10 keys, U1 to U10.
groups, the lower keyboard has 10 groups from L1 to L10,
The foot keyboard has four groups, P1 to P4.
The characters written at the left end of the table are hexadecimal representations of event memory addresses (hereinafter also abbreviated as EMA), which in the present invention are the same as scan codes, as can be seen from FIG. C ₂ ... C ₇ shown in the table correspond to the keys, and the diagonally shaded (/) parts are unused. Table 2 shows the number of simultaneous pronunciations for the upper, lower, and foot keyboards, 7,
7 shows the configuration of the assignment memory 18 when the channel is set to 7.2. Each channel is USE ON/OFF, which turns ON when the key is turned ON, and turns OFF after the key turns OFF and when musical tone generation ends.
KEY that supports ON/OFF of bits and keys
Consists of a total of 8 bits: ON/OFF bit, keys C ₂ , C ₂ # ...B ₆ , C ₇ to express key numbers numbered 0 to 60 to express key information (scale), and 6 bits to express key numbers. Suppose that it is done. A ₀ to A ₁₅ at the left end of the table are addresses of the assignment memory 18 (hereinafter AMA
(also abbreviated). This table shows the contents at the time of initialization. Table 3 shows the configuration of the count memory 19. When all tone generators are used and a key is pressed, the assignment memory 1
The number of channels corresponds to the number of channels in the assignment memory 18. The initial value of the counter value is set to “0=OOH (hexadecimal)” or “255=FFH (16
It doesn't matter whether it is done (in progress) or not. If the former, perform addition to find the maximum value, and if the latter, perform subtraction to find the minimum value. When adding or subtracting and there is a gain or borrow, in this invention, it is called “FFH”.
However, this is because it is expressed in 8 bits and does not limit the present invention. Table 4 shows the configuration of the evacuation memo 20, in which even though a key is pressed, it is forcibly removed because the pressed key is assigned to a key pressed more than the number of simultaneous polyphony. The key information is stored so that it can be restored when the number of pressed keys falls below the number of simultaneous polyphony. For writing (saving) to the save memory and reading (returning) from the save memory, it is preferable to execute the last in-first out method (the key information input last is read first). It is necessary to secure an area in the save memory 20 that is equal to the maximum number of keys pressed minus the number of simultaneous sounds. In other words, each of the upper, lower, and foot keyboards

【table】

【table】 USE KEY 〓

Claims (1)

[Claims] 1. In the keyboard circuit assignment method, which has a musical tone generator that can produce fewer simultaneous sounds than multiple keys, and which detects the on/off state of a key switch in response to key presses and key releases and assigns it to channels, The key includes means for newly assigning the key information of the newly pressed key to the channel of the key that is released first among the keys that are being sounded at the same time. The key information of the channel of the key pressed first among the keys is saved in a separately provided save memory, and the key information of the newly pressed key is newly assigned to the empty channel. 1. A method for allocating a keyboard circuit, comprising means for newly allocating the saved key information from the save memory when the number of simultaneous pronunciations falls below.