Beyond von Neumann--logic operations in passive crossbar arrays alongside memory operations

Area of Science:

• Materials Science
• Computer Engineering
• Nanotechnology

Background:

• Passive crossbar memory arrays offer potential for expanded applications through integrated logic operations.
• Memristive crossbar junctions have been proposed to perform material implication logic.
• Single bipolar resistive switches (BRS) and complementary resistive switches (CRS) have demonstrated capability for logical functions.

Purpose of the Study:

• To systematically analyze Boolean functions realizable by memristive crossbar cells.
• To demonstrate the feasibility of performing a wide range of logic operations within memory arrays.
• To establish the potential for direct storage of logic operation results in memory.

Main Methods:

• Systematic analysis of all 16 Boolean functions.
• Utilizing single bipolar resistive switches (BRS) and complementary resistive switches (CRS) as computational elements.
• Sequential application of logic operations in at most three cycles.

Main Results:

• Demonstrated that 14 out of 16 Boolean functions can be realized using a single BRS or CRS cell.
• Showcased the ability to perform logic operations within at most three sequential cycles.
• Confirmed that the read-out step is independent of the logic operation steps.

Conclusions:

• Memristive crossbar architectures can effectively implement a majority of Boolean functions.
• The independence of read-out from logic operations facilitates direct data storage.
• This research paves the way for practical logic-in-memory applications.