Akihiko Hyodo

A power reduction scheme for data buses by dynamic detection of active bits

To transfer a small number, we inherently need the small number of bits. But all bit lines on a data bus change their status and redundant power is consumed. To reduce the redundant power consumption, we introduce a concept named active bits. In this paper, we propose a power reduction scheme for data buses using the active bits. Suppressing switching activity of inactive bits, we can reduce redundant power consumption. We propose various power reduction techniques using active bits and the implementation methods. Experimental results illustrate 20% - 35% on average and up to 54.2% switching activity reduction.

A Power Minimization Technique for Arithmetic Circuits by Cell Selection

As a basic cell of arithmetic circuits, a one-bit full adder and a counter are usually used. Minimizing power consumption of these components is a key issue for low-power circuit design. This paper proposes a new design method, in which basic cells are selected from a set of circuits with different structures (symmetrical and asymmetrical) and connections to their terminals are exchanged, according to input-patterns to minimize power consumption. Experimental results for a parallel multiplier demonstrate average 30% power reduction.

Bitwidth Optimization for Low Power Digital FIR Filter Design

We propose a novel approach for designing a low power datapath in wireless communication systems. Especially, we focus on the digital FIR filter. Our proposed approach can reduce the power consumption and the circuit area of the digital FIR filter by optimizing the bitwidth of the each filter coefficient with keeping the filter calculation accuracy. At first, we formulate the constraints about keeping accuracy of the filter calculations. We define the problem to find the optimized bitwidth of each filter coefficient. Our defined problem can be solved by using the commercial optimization tool. We evaluate the effects of consuming power reduction by comparing the digital FIR filters designed in the same bitwidth of all coefficients. We confirm that our approach is effective for a low power digital FIR filter.