ABSTRACT
This chapter discusses perspectives for SUM devices, the conceptual background for such devices as well as applicability, and functionality of the devices for current and future digital systems. The SUM devices are nonvolatile and are proposed to replace conventional memories in functionality for all digital systems as well as the conventional memory hierarchy for digital systems within a unified memory architecture and technology framework. SUM applicability is intended to span entire range of digital electronics. At the low end, it is expected to be an integral part of a silicon based system-on-chip (SOC) solution fulfilling the roles of BIOS, code, and data simultaneously, while directly interacting with the built-in registers and caches associated with the processor or controller through a common bus. SUM devices are broadly classified into two groups distinguished from each other from standpoint of memory cell functionality, yet unified from standpoint of technology integration and scalability within each other and within framework of silicon based logic technology.
