During the last years, mobile devices have taken an important place in everyday life (smartphones, ultrabooks…) and we are still demanding faster speed of operation, better display resolution and longer battery life. Transistors have been until recently improved following Moore’s law. Unfortunately, battery technology has been following a slower trend of improvement. Besides, supercomputers and data centers are highly energy consuming and need complex and expensive cooling systems. As the end of Moore’s law is predicted, technology scaling will no longer be the solution to reduce the power consumption. Thus, one of the main challenges in today’s circuits design is to improve the energy efficiency ratio.
Usually, the main parameters considered during circuit design are the speed of operation, power consumption, area occupied on the silicon and reliability. While the notion of exact computation has been dominant for many decades, it has been shown that accuracy can be traded for signi