US Patent 7355873 Highly integrated ternary semiconductor memory device

A TCAM (ternary content addressable memory) cell array is provided with a search input node into which one bit of search data is inputted, a plurality of data input nodes into which a bit corresponding to one bit of search data is inputted, and a plurality of memory cells arranged in rows and columns. Each of the plurality of memory cells further includes a first cell storing one bit of said storage data, and a logical operation cell determining whether or not said search data and storage data match. A gate of a transistor forming each of a plurality of memory cells extends along the direction of said rows. Each of a plurality of wells in the region where the memory array is formed is formed so as to continue to a corresponding well of an adjacent memory cell in the direction of said columns.