Low power CORDIC implementation using redundant number representation

Abstract

In this paper a methodology for reducing the power consumption of shift-and-add operations in general and especially of CORDIC stages is presented. The proposed method uses the fact of simultaneous carry generation in redundant carry-save and signed digit structures to predict the minimum necessary hardware effort for shift-and-add operations. As a carry once generated in a certain bit position cannot "ripple" through the adder if using redundant number representation, hardware parts can be switched on or off depending on the shift constant. Simulations have shown, that shift dependent hardware utilization of parallel implementations leads to monotonically decreasing power consumption for increasing shift constants. A CORDIC processor element for 16 digit SDNR has been implemented as a layout and simulated with PowerMill in terms of power consumption.