Integrated Memristor-Based Computer Architectures

• Applicants: Professor Dr.-Ing. Dietmar Fey; Professorin Dr.-Ing. Amelie Hagelauer; Professor Dr.-Ing. Marc Reichenbach
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 389549790

In recent years, in the development of memristive devices significant progress has been attained, so that the commercialization of new background memory systems based on this technology has already begun. In present research memristive devices are only used for storing data but not for the processing of data inside a CPU. However, from an energy point of view and based on the memristors non-volatile behavior, memristive devices should also be of interest for data processing, especially for CPUs in IoT-devices utilizing a volatile power supply. Therefore, the aim of this project is to use memristor technology in modern computer architectures; especially for the integration of memristive devices in a CPU for embedded applications. For a further reduction of the energy consumption also the ability of storing more than one bit in a single memristor cell can be used to enable the realization of tenary logic, which requires multi-bit-storage in a memristive register. Tenary logic will result in a redundant number representation, which allows to execute an adding during a constant time independent of the word length. This also results in a decreased power consumption.Due to the compatibility of the memristors technology with standard CMOS processing, an integration of memristors will be possible by postprocessing the chip. However, currently an automated and tool-aided design flow for memristive devices, especially for digital designs, is not available. Instead, dedicated mixed signal circuits have to be developed to enable the use of memristors also in the digital world. Regarding the realization of the tenary logic the problem has to be solved to what extent ceaseless conversions between the analog and the digital domain make sense. Therefore, in addition to the integration of memristors a further goal of this project is the development of a tenary processor architecture utilizing memristive devices. For the realization of such an architecture, e.g., basic mixed-signal blocks can be used. Consequently, memristors will not only be used as pure storage devices but will be part of the data processing within a CPU.The computer architectures will be realized as a prototype IC and verified. The integration of the memristive devices is done through a special BEOL processing in which the memristors will be placed at the top chip layer. Using appropriate benchmarks a qualitative and quantitative evaluation of the developed architectures will be performed to assess the usefulness of memristors for data processing in modern CPUs. A final evaluation shall result in the identification of possible applications fields of the designed architecture.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr.-Ing. Robert Weigel