Processing device performing plural operations for plural tones in

Abstract

A digital signal processor (i.e., DSP) is employed by an electronic musical instrument. The contents of operational processes to be executed by the DSP can be arbitrarily set in accordance with filtering operations of the filters to be realized. A processing device to be embodied by the DSP at least contains a microprogram memory, a coefficient register, a delay memory and a processing portion. A desired set of coefficients are read from the coefficient register in accordance with a first address signal, while a desired program is read from the microprogram memory in accordance with a second address signal. Each program contains at least one operational command or one instruction. The value of each of the first and second address signals is periodically changed in each sampling period. During a writing operation of the delay memory, results of the operational processes effected by the processing portion are written into the delay memory, while the processing portion effects the operational processes on the musical tone signals, sequentially inputted thereto, in accordance with the desired program to be repeatedly executed for the desired set of coefficients. When a reading operation of the delay memory is designated, the processing portion effects the operational processes on data read from the delay memory. Thus, the processing device can perform the pipeline processing effectively on plural series of musical tone signals with a reduced storage capacity of the microprogram memory.