| 摘要 |
A finite impulse response filter of 1:4 interpolation with 108 taps for outputting filter output data of 8 bits with respect to filter input data of 4 bits includes four shifting and storing unit of 27 bits for unifying bits of filter input data of 4 bits, which is 2's complement to shift and store the bi-unified input data, first selection unit for selecting any one of the input data stored in the four shifting and storing unit of 27 bits, address generating unit for generating addresses of lookup tables corresponding to each of a plurality of filter coefficients groups, first to fourth lookup table groups for generating filter outputs of each filter coefficients group, four accumulating unit for shifting the filter outputs of the filter coefficients groups respectively outputted in parallel from the first to the fourth lookup table groups, and second selection unit for serially converting the outputs from each of the four accumulators in accordance with filter coefficients groups.
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