Sum-of-products computation based on a weight-sorting algorithm

An architecture for sum-of-products computation using conventional carry-save-adder arrays including even/odd CSA array is regular, however, it results in awkward inter-layer interconnections and elongated interconnection length. We introduce a "weight-sorting" CSA array which minimizes the interconnection complexity. This array can be designed in a systematic way and laid out regularly in a VLSI circuit using narrow cells. A comparison is made between three CSA arrays at an architectural level. The design of a 8/spl times/8 sum-of-two-products computer using the weight-sorting algorithm and the narrow cells is studied as an illustration.