Cascade filter structure with time overlapped partial addition operations and programmable tap length

摘要

A filter structure uses multiple discrete filter circuits which are cascaded to provide a multiple tap filter of programmable tap length. In one form, an FIR filter may be implemented wherein each circuit generates partial sum operands which must be added to provide a filter output. The cascaded circuits perform partial addition operations near simultaneously by using a serial addition which is synchronized with a start bit. The number of taps in the filter structure implemented by the cascaded discrete filter circuits is variable and may be programmed with a programmable storage register in each discrete circuit which stores operand data fixing the tap length of each discrete circuit. The multiple filter circuits provide a single filter structure with a large tap length and high sampling rate.