Digit pipelined processors

Abstract

Digit serial data transmission can be used to an advantage in the design of special purpose processors where communication issues dominate and where digit pipelining can be used to maintain high data rates. VLSI signal processing applications are one such problem domain. We have developed a family of VLSI components that have digit serial transmission and that can be pipelined at the digit level. These components can be used to construct VLSI processors that are especially suited to signal processing applications. One such particularly attractive processor is a structure we call the arithmetic cube. The arithmetic cube can be programmed to solve linear transformations such as convolutions and DFTs, and has nearest neighbor interconnects, regular layout, simple control, and a limited number of interconnections. Regular layout and simple control derive naturally from the algorithms on which the processor is based. Long wires are eliminated by the nearest neighbor interconnect. High throughput can be achieved by pipelining the processor at the digit level. The arithmetic cube is programmable in the problem size n; once implemented for a certain size N, smaller problems can be solved on the same implementation without a loss in performance. In addition, the architecture extends to larger N in a regular and automatic fashion.