Digital signal processor and control method for changeover of sampling frequency

摘要

A frequency counter detects a sampling frequency of an input digital signal. If a control circuit is notified that the sampling frequency of the input digital signal changes according to a signal from the frequency counter, it temporarily stops accumulation of input digital signal in a data memory. An operation processing circuit continues operation processing on the input digital signal accumulated in the data memory at that time. After the operation processing terminates, the control circuit reads a program and processing data corresponding to the changed sampling frequency from a program memory and a coefficient/offset data memory and sets them in the operation processing circuit. After that, the operation processing circuit restarts operation processing.