Memristor Content Addressable Memory

Content addressable memory is a novel storage device that can save data in its cells, which could be read, written and searched on the basis of their contents. This paper presents Memristor content addressable memory (M-CAM) structures that are formed of M-CAM cells, which compare searched data and stored data then give a cell output signal to be kept in its comparator. After the comparison in each cell, reading is enabled at each row of all comparators. The current of each row could be measured, if some comparators are high resistance (0) in a row, the current of that row could be lower than the current from another row where all comparators are low resistance (1), which means the corresponding row is a match. The main emphasis of this paper is to highlight the process of the M-CAM comparison and how to get the match entry. Our experimental results show that M-CAM is able to not only query accurately, but also fuzzy lookup through setting the memristor off-to-on resistance ratio.