Input Vector Control and Leakage Reduction

 Input vector control and leakage reduction are two important techniques used in physical design to reduce power consumption and improve the energy efficiency of digital circuits.

Input Vector Control: Input vector control is a low power technique that involves controlling the input vectors to reduce the number of switching events and thereby reduce the dynamic power consumption of the circuit. This is achieved by controlling the inputs to the circuit such that the switching activity is reduced, resulting in lower dynamic power consumption.

Leakage Reduction: Leakage power is the power that is consumed even when the circuit is not actively switching. Leakage reduction techniques aim to minimize this power consumption. Some common leakage reduction techniques are:

Threshold voltage adjustment: The threshold voltage of the transistors in the circuit can be adjusted to reduce the leakage current and thereby reduce the leakage power.

Dual Vt cell libraries: The use of cells with two threshold voltages can reduce the leakage power by using high-threshold transistors for the leakage-sensitive portions of the circuit.

Power gating: This technique involves turning off the power supply to blocks of the circuit that are not in use, reducing the overall power consumption, including leakage power.

Body biasing: This technique involves biasing the body of the transistors in the circuit to control the leakage current and reduce the leakage power.

By combining input vector control and leakage reduction techniques, significant reductions in power consumption can be achieved in physical design.