During the 1990\u27s the main focus of chip design methodologies was on the timings and area constraints. Power consumption was considered significant only after a drastic increase of device densities from 130nm on as well as dramatic increases in sub threshold leakage. As technology advanced from 130nm to 90nm and below there was a significant increase in leakage current due to lower threshold voltage and the influence of the deep submicron effects. High power consumption causes different problems such as increasing the cost of the product, reducing the reliability, reducing the battery life among others. Therefore EDA tools were designed to maximize the speed while minimizing area and only recently focused on improving power. The main obj...