Spatial correlation-aware statistical dual-threshold voltage design of template-based asynchronous circuits

Purpose Power consumption is a top priority in high-performance asynchronous circuit design today. The purpose of this study is to provide a spatial correlation-aware statistical dual-threshold voltage design method for low-power design of template-based asynchronous circuits. Design/methodology/approach In this paper, the authors proposed a statistical dual-threshold voltage design of template-based asynchronous circuits considering process variations with spatial correlation. The utilized circuit model is an extended Timed Petri-Net which captures the dynamic behavior of the asynchronous circuit with statistical delay and power values. To have a more comprehensive framework, the authors model the spatial correlation information of the circuit. The authors applied a genetic optimization algorithm that uses a two-dimensional graph to calculate the power and performance of each threshold voltage assignment. Findings Experimental results show that using this statistically aware optimization, leakage power of asynchronous circuits can be reduced up to 3X. The authors also show that the spatial correlation may lead to large errors if not being considered in the design of dual-threshold-voltage asynchronous circuits. Originality/value The proposed framework is the scheme giving a low-power design of asynchronous circuits compared to other schemes. The comparison exhibits that the proposed method has better results in terms of performance and power. To consider the process variations with spatial correlation, the authors apply the principle component analysis method to transform the correlated variables into uncorrelated ones.

Sleep signal controlled footless domino circuit for low leakage current

Purpose This paper aims to propose a new sleep signal controlled footless domino circuit for reducing the subthreshold and gate oxide leakage currents. Design/methodology/approach In the proposed circuit, a P channel MOSFET (PMOS) sleep switch transistor is inserted between the power supply and the output node. The sleep transistor, the source of the pull-down network, and the source of the N channel MOSFET (NMOS) transistor of the output inverter are controlled by this additional sleep signal to place the footless domino circuit in a low leakage state. Findings The authors simulate the proposed circuit by using HSPICE in 45-nm CMOS technology for OR and AND logic gates such as OR2, OR4, OR8, AND2 and AND4 at 25°C and 110°C. The proposed circuit reduces leakage power consumption as compared to the existing circuits. Originality/value The proposed circuit significantly reduces the total leakage power consumption up to 99.41 and 99.51 per cent as compared to the standard dual-threshold voltage footless domino circuits at 25°C and 110°C, respectively, and up to 93.79 and 97.98 per cent as compared to the sleep control techniques at 25°C and 110°C, respectively. Similarly, the proposed circuit reduces the active power consumption up to 26.76 and 86.25 per cent as compared to the standard dual-threshold voltage and sleep control techniques footless domino circuits at 25°C and 110°C, respectively.