| 摘要 |
Instead of adding the partial products computed from a set of input values in each cycle, a set of partial products computed from the same input value are accumulated in a set of accumulators, the output of that accumulator holding the full sum of products required for the present output value being selected as the current filter output value and then being re-used for accumulating a later filter output value. When the output data rate is lower than the input data rate the number of multipliers can be reduced. For example, to implement a seven-tap filter with two-to-one decimation, four multipliers are required instead of seven multipliers (figure 40). When used in image scaling, the effective number of taps beneficially increases as the scale factor reduces. |
