Spintec Laboratory, in collaboration with the Circuits Multi-Projects service, the Laboratory of Informatics, Robotics and Microelectronics of Montpellier and the Fundamental Electronics Institute, has developed a set of software tools to evaluate the gains that can be expected by introducing Magnetic Tunnel Junctions (MTJs) in integrated circuits, including processors.
Today, integrated electronic circuits are based on the use of CMOS transistors (Complementary Metal Oxide Semiconductor). For over 40 years, this technology has been following Moore's law, stating that the speed and density of integration of circuits should double every 18 months. But this trend begins to get out of breath for technology nodes beyond 90nm: indeed, the extreme miniaturization of transistors leads to insoluble problems of power consumption, heating and reliability. Leakage currents become so strong that in a modern chip, half of consumption appears even when the circuit is not working!
One possible answer to these problems is the use of new non- volatile magnetic devices to come support the transistors. These devices, capable of retaining information without power, allow removing the static power consumption by cutting of the power supply of inactive parts of the circuit. In this context, the advantages of MTJs in terms of speed, writing power and endurance allow a mixing of calculation and memory functions which were so far separate parts of the circuit. Beyond the energy savings, this hybridization improves reliability and creates new features like instant-on circuits in the last operating state.
Software tools that we have developed for design and simulation were used to estimate the gain of these hybrid circuits to a factor of 10 regarding power consumption. These results, however, only consider the introduction the new devices, but mixing CMOS and magnetic will also lead us to rethink the architecture of circuits to take full advantage of the features of this technology. The gains could then be even more obvious in the future.
Last update : 04/29 2014 (1028)