Digital filter and digital signal processing system

摘要

In a direct type of finite impulse response (FIR) digital filter, direct type digital filters consisting a plurality of taps are used as a construction element of a digital filter. A pipeline structure is constructed between cascaded construction elements, and the sum and carry signals of the multi-input addition in the midst of the addition operation are transferred between cascaded construction elements. The number of gates, dissipation power, chip area and the like can be decreased as compared with a prior art inverted type digital filter. Further, a digital signal processing system such as a waveform equalizing system can be constructed using a direct type digital filter as mentioned above, and such a system includes a selector for selecting the output of the digital filter and an output in the midst of the delays in the digital filter.