Abstract: A method of processing input digital audio signals of different sampling rates, includes steps of: providing a digital filter circuit having a random access memory (RAM) for storing input digital audio signals of different sampling rates for each of channels, a read only memory (ROM) for storing groups of digital filter coefficients, and an accumulator for executing multiplications and additions based on the input digital audio signals and the digital filter coefficients; reading the input digital audio signals of each sampling rate from the RAM; reading the digital filter coefficients of each group from the ROM; sequentially allocating one of divided time portions of one cycle of a unified sampling rate to the digital filter circuit, so that the accumulator executes the multiplications and additions for each channel during the allocated time portion so as to produce processed digital audio signals for all the channels within the one cycle; and outputting the processed digital audio signals for each of the ch

Abstract: An information processing device includes a random access memory storing parallel program data, a counter generating a first address supplied to the random access memory and a second address, and a selector for converting the parallel program data read out from the random access memory in accordance with the first address into serial program data when the second address generated by the address generator is applied to the counter. Further, the information processing device includes a circuit for converting the serial program data into a cyclic code signal and outputting the cyclic code signal to an external device in which the cyclic code signal is compared with a reference cyclic signal formed on the basis of correct program data corresponding to the program data stored in the random access memory.