2C-Ternary Content Addressable Memory in Memcapacitor Crossbar Array with NAND Flash Structure.

Area of Science:

• Materials Science
• Computer Engineering
• Electrical Engineering

Background:

• Ternary content-addressable memory (TCAM) offers efficient in-memory searching for high-throughput, low-latency computing.
• Resistive non-volatile memory-based TCAMs suffer from limited resistance ratios, impacting sensing margin and energy efficiency.

Purpose of the Study:

• To propose and validate a novel TCAM cell design using two memcapacitors (2C-TCAM) for improved performance.
• To address the limitations of existing TCAM technologies, particularly concerning resistance ratio and energy consumption.

Main Methods:

• A 2C-TCAM cell architecture was designed, leveraging memcapacitors integrated with NAND flash array structures.
• Experimental validation involved fabricating and measuring the electrical characteristics of the 2C-TCAM cell.
• Array-level operations were demonstrated using a 24 × 48 memcapacitor crossbar array and analyzed for system performance.

Main Results:

• The 2C-TCAM design achieves near-zero static power consumption and minimizes the IR drop effect through capacitive readout.
• Highly parallel and reliable search functionality was maintained even in large arrays, preserving the sensing margin.
• Achieved search times of 47 ps and energy consumption of 11.7 fJ per bit with a scaled cell area of 1 µm².

Conclusions:

• The proposed 2C-TCAM cell offers a promising solution for energy-efficient and high-performance in-memory computing.
• The memcapacitor-based approach overcomes key challenges in traditional TCAMs, enabling reliable operation in dense memory arrays.
• This technology paves the way for advancements in data-intensive computing applications requiring fast and low-power search capabilities.