Very Large Scale Integration (VLSI) is all about Silicon chips-putting more functionalities into that tiny silver of silicon. It is recognised as a vital ingredient of electronics equipment and systems. Much of the recent growth in the IC industry is due to the growth in demand for Internet infrastructure and wireless communications markets. While the IC markets are experiencing phenomenal growth rates, the IC technology marches on. The current world wide electronics industry is about US$1.2 trillion. Today 20-30% of car's cost is made up of electronics. The driving force behind integrated circuit (IC) design is becoming more complex everyday especially when analog and digital signals are getting more closely connected.