Electronic musical instrument

Abstract

An electronic musical instrument which has a keyboard and creates a musical tone by striking keys of the keyboard, is provided with an operation control circuit and an adder both for effecting keyboard switch chattering prevent operation processing and touch response select operation processing, a timing control circuit for controlling the switching between the chattering preventing operation and the touch response detecting operation and the scanning of the keyboard switches to detect their status, a musical tone generator for performing a musical tone generating operation asynchronously with the keyboard switch scanning operation, the keyboard switch chattering preventing operation and the touch response detecting operation, and a transfer circuit for transferring touch response information to the musical tone generator. High-speed touch response detecting operation processing and chattering preventing operation processing which are difficult to execute by a CPU are carried out by the operation control circuit and the adder on a time-shared basis, and data is properly transferred to the musical tone generator which performs the musical signal generating operation asynchronously with the abovesaid operations, thereby implementing low cost touch response processing which is free from hardware limitations on the number of tones to be simultaneously produced and the generator assignment system. Furthermore, data for internal processing is set for two words on a time-shared basis, and touch response data which has such a natural temporal variation curve as is obtainable with a time constant circuit system is directly operated by the operation control circuit and the adder is then rendered to one-word external output data of high precision and resolution, thereby effectively reflecting the tough response data in musical parameters of musical tones to be created.