Two-dimensional digital filtering using constant-I/O systolic arrays

Systolic arrays with a constant number of input/output (I/O) ports for two-dimensional finite impulse response (FIR) and infinite impulse response (IIR) filtering are presented. The authors´ design has an array of L × N processing elements (PE´s), where L (⩽ N) is a technology-dependent parameter related to the number of I/O ports. Each PE in the design has a microprogrammed arithmetic logic unit (ALU), a control unit, a fixed number of I/O buffers, and O(N/L) memory. The design specializes to a square mesh when L = N, and a linear array when L = 1. It can implement both FIR and IIR filtering in O(N²M/L) time which is asymptotically optimal