Patent ID: 7334010

Claim:
A feedback digital filter for multichannel data, comprising: a control section; a data storage section for inputting and separately storing first channel data and second channel data, and selectively outputting the first channel data or the second channel data in response to a data selection signal from the control section; a coefficient storing section for storing volume and filter coefficients; a selector for selecting one of the coefficients and outputting the selected coefficient in response to a coefficient selection signal from the control section; a multiplier for multiplying the data output from the data storage section and the selected coefficient output from the selector, the multiplier outputting a multiplication result; an accumulative adder section for accumulatively adding the multiplication result and outputting an addition result; a feedback loop for storing the addition result in the data storage section in response to a storage signal from the control section, whereby in response to another data selection signal the addition result is supplied to the multiplier and multiplied by another, different coefficient from the coefficient storing section to result in another addition result; and a first data output section and a second data output section, coupled to the accumulative adder section, for outputting first channel output data and second channel output data from the digital filter, after a predetermined number of iterations of data fed back to the data storage section, wherein the multiplier multiplies data from the data storage section by both volume and filter coefficients, wherein the first channel data and the second channel data have different sampling frequencies, and wherein the data selection signal causes the first channel data to be inserted in every frame and the second channel data to be inserted once in two frames.