A dynamic content addressable memory using a 4-transistor cell

Abstract

A novel ternary dynamic content addressable memory cell with coupled match lines is presented here. The dynamic CAM cell contains only four n-type transistors. This cell is capable of storing and matching three states, hence the term ternary; these states are: zero (0), one (1) and don't care (X). Circuit simulations show that our dynamic CAM cell performs all the basic operations (read, write and match) at a good speed. In order to use the proposed cell in a CAM array, we developed a cut-off scheme to deal with coupling.