Bit-level pipelined 2-D digital filters for real-time image processing

Bit-level systolic arrays for real-time 2-D FIR and IIR (finite and infinite impulse response) filters are presented. Two-dimensional iteration and retiming techniques are depicted to illustrate block pipeline 2-D IIR filters, which guarantee high-throughput operation for real-time applications. The block (parallel) systolic architectures are refined down to the bit level. This increases the filter's throughput rate and decreases the filter's development and manufacturing costs. The AP figure is improved from O(N²W³) for the previous design to O(N²W² ), i.e. by a factor of O(W), where W is the word length. Pipelining at the bit rate level is the major reason for this improvement. Another advantage of the proposed design is that it has simpler wire routing and control circuitry. In summary, these systolic-array realizations are more cost effective; more regular structurally; composed of bit-level cells and latches; and fully pipelined at the bit level