A SAT-Based Methodology for Effective Clock Gating for Power Minimization

Abstract

A possible solution to handle the rising complexity of modern Systems-on-Chip (SoCs) is to raise the level of abstraction for the design and optimization. A better optimization of performance and power can be achieved at higher abstraction levels by applying suitable optimization techniques. Insertion of clock gating logic into the generated Register-Transfer Level (RTL) would facilitate lowering dynamic power consumption by switching off the clock signal to portions of the circuit not currently in use and thereby reducing unnecessary toggling. In this work, we have tried to minimize the power consumption of synchronous circuits by reducing the number of activity string patterns. Activity-driven clock trees have been used wherein sections of the clock tree are turned off by gating the clock signals. Since gating the clock signal implies additional control signals and gates, there is always a trade-off existing between the logic circuit area overhead and the total power consumption of the clock tree. A pseudo-Boolean satisfiability (PB-SAT)-based approach is proposed in this work which focuses on the reduction of power consumption by reducing the activity pattern of the clock tree which will reduce the power consumption with appropriate module-binding solutions.