基于MRAM的新型存内计算范式OACSTPCD

Computing-in Memory(CIM)is an emerging architecture to alleviate"memory walls"and"power consumption walls".With further expansion of the imbalance between CPU processing speed and memory access speed,structures that separate the central process and memory,such as the Von Neumann architecture,lose its superiority.CIM proposes a novel structure that combines the compute unit and the storage to reduce data movement,significantly improving computational efficiency.MRAM,as one of the most promising next-generation nonvolatile memory devices,is also considered a strong candidate for building efficient CIM architectures.CIM based on MRAM can be divided into analog MRAM CIM and digital MRAM CIM according to the different calculation processes.Digital MRAM CIM can be further divided into MRAM write-type CIM,MRAM read-type CIM,and MRAM near memory computing(MRAM NMC)based on how digital logic is generated.Analog MRAM CIM utilizes high parallelism to amortize energy consumption,which has unparal-leled advantages in throughput and energy efficiency per unit area compared to digital CIM.However,It is also limited due to its suscepti-bility to PVT and other characteristics.The implementation methods of digital MRAM CIM are diverse,and write-type CIM almost elim-inates data movement outside the memory.Although the flip energy consumption and delay required by the current process of MRAM are too large,which leads to this method staying in the simulation,it does not hinder that write-type CIM is one of the most effective means to alleviate the"memory wall".Read-type CIM relies on the functional design of read amplifiers which has severe limitations,but there still have some developments in the related field.NMC method is an optimal solution that combines the advantages of MRAM non-volatile devices and CMOS circuits,though there are significant differences in speed and computational energy efficiency between this two devices,and has achieved significant benefits in practical applications.