Multi-stage filter processing device and method

A multi-stage filter processing device that performs filter calculation processing composed of a plurality of stages on input data to generate output data, the multi-stage filter processing device comprising:

• a filter calculation unit that performs the filter calculation processing for each stage;
• a processing data holding unit that holds the input data or intermediate data generated by the filter calculation unit during the stages before a final stage is reached;
• a measurement unit of number of data that measures, at each of the stages, a number of data of the input data or the intermediate data;
• a coefficient data holding unit that holds a coefficient data regulating a number of data sufficient to perform the filter calculation for each of the stages;
• and
• a stage switching control unit that controls switching of the stages in the filter calculation processing, the stage switching control unit,
• making the processing data holding unit hold the input data or the intermediate data generated in a current stage until the number of data reaches a data quantity sufficient to perform the filter calculation processing in the current stage on the basis of the coefficient data,
• inputting all of the input data or all of the intermediate data held by the processing data holding unit to the filter calculation unit when the number of data reaches the data quantity sufficient to perform the filter calculation processing;
• and
• making the filter calculation unit perform the filter calculation processing of the current stage,
• wherein the filter calculation unit comprises registers for all of the stages, stores a result of a product-sum operation for the input data or the intermediate data read from the processing data holding unit and the coefficient data, in the registers corresponding to the current stage, selects one of the input data and data stored in the registers using an arbiter, and outputs selected data and data indicating the current stage.