  The landscape of emerging applications has been continually widening,
encompassing various data-intensive applications like artificial intelligence,
machine learning, secure encryption, Internet-of-Things, etc. A sustainable
approach toward creating dedicated hardware platforms that can cater to
multiple applications often requires the underlying hardware to context-switch
or support more than one context simultaneously. This paper presents a
context-switching and dual-context memory based on the standard 8T SRAM
bit-cell. Specifically, we exploit the availability of multi-VT transistors by
selectively choosing the read-port transistors of the 8T SRAM cell to be either
high-VT or low-VT. The 8T SRAM cell is thus augmented to store ROM data
(represented as the VT of the transistors constituting the read-port) while
simultaneously storing RAM data. Further, we propose specific sensing
methodologies such that the memory array can support RAM-only or ROM-only mode
(context-switching (CS) mode) or RAM and ROM mode simultaneously (dual-context
(DC) mode). Extensive Monte-Carlo simulations have verified the robustness of
our proposed ROM-augmented CS/DC memory on the Globalfoundries 22nm-FDX
technology node.
