A Self-Disabled Sensing Technique for Content-Addressable Memories

A low-power content-addressable memory (CAM) using a differential match line (ML) sense amplifier is proposed in this work. The proposed self-disabled sensing technique can choke the charge current fed into the ML right after the matching comparison is generated. Instead of using typical nor/ nand-type CAM cells with the single-ended ML, the proposed novel nand CAM cell with the differential ML design can boost the speed of comparison without sacrificing power consumption. In addition, the 9-T CAM cell with disabled read-out circuit provides the complete write, read, and comparison functions to refresh the data and verify its correctness before searching. The CAM with the proposed technique is implemented on silicon to justify the performance by using a standard 0.13-¿m complementary metal-oxide-semiconductor process. The energy consumption of the searching process is 1.872 fJ/bit/search.