Hirofumi Shinohara

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Scaling power supply voltages (V DD 's) of logic circuits down to the sub/near-threshold region is a promising approach to achieve significant power reductions. Circuit delays in the ultra-low voltage region, however, are extremely sensitive to process, voltage, and temperature (PVT) variations, and hence, large timing margins are required for worst-case(More)
In this paper, a closed-form expression for estimating a minimum operating voltage (V<sub>DDmin</sub>) of CMOS logic gates is proposed. V<sub>DDmin</sub> is defined as the minimum supply voltage at which circuits can operate correctly. V<sub>DDmin</sub> of combinational circuits can be written as a linear function of the square-root of logarithm of the(More)
6T-SRAM cells in the sub-100 nm CMOS generation are now being exposed to a fatal risk that originates from large local Vth variability (/spl sigma//sub v/spl I.bar/Local/). To achieve high-yield SRAM arrays in presence of random /spl sigma//sub v/spl I.bar/Local/ component, we propose worst-case analysis that determines the boundary of the stable Vth region(More)
A 32-bit CPU which operates with the lowest energy of 13.4 pJ/cycle at 0.35V and 14MHz, operates at 0.22V to 1.2V and with 0.14µA sleep current is demonstrated. The low power performance is attained by Reverse-Body-Bias-Assisted 65nm SOTB CMOS (Silicon On Thin Buried oxide) technology. The CPU can operate more than 100 years with 610mAH Li battery. Extended(More)
Error Detection FFs for Dynamic Voltage Scaling (DVS) has been proposed. This technique controls the clock phase based on the timing slack, and reduces the energy consumption by 19.8% compared to non-DVS. The error signal latency is shortened to 6.3%, the area and power penalties for delay buffers on short paths become 35.0% and 40.6% lower compared to the(More)
— Contention-less flip-flops (CLFF's) and separated power supply voltages (V DD) between flip-flops (FF's) and combinational logics are proposed to achieve a maximum energy efficiency operation. The proposed technologies were applied to a 16-bit integer unit (IU) for media processing in a 65-nm CMOS process. Measurement results of fabricated chips show that(More)
For Dynamic Voltage Scaling (DVS), we propose a novel design methodology. This methodology is composed of an error detection circuit and three technologies to reduce the area and power penalties which are the large issues for the conventional DVS with error detection. The proposed circuit, Phase-Adjustable Error Detection Flip-Flip (PEDFF), adjusts the(More)