Design and Implementation of Low-power

With the increasing level of device integration and the growth in complexity of microelectronic circuits, power dissipation, delay and area has come the primary design goal. The failure mode of high-power circuits relates to the increasing popularity of portable electronic devices. Laptop computers, pagers, portable video players and cellular phones all use batteries as a power source, which by their nature provide a limited time of operation before they require recharging. To extend battery life, low power operation is desirable in integrated circuits. Furthermore, successive generations of applications often require more computing power, placing greater demands on energy storage elements within the system.Addition is the most basic arithmetic operation and adder is the most fundamental component of any digital processor. Depending on the area, delay and power requirements, several adder configurations such as ripple carry, carry look ahead, carry-skip, and carry select are available in the literature. The ripple carry adder (RCA) is the simplest adder, but has the longest delay because every sum output needs to wait for the carry-in from the previous adder cell.