In a memory array comprising memory cells employing a memory circuit STC and a comparison circuit CP, any one of source and drain electrodes of a transistor having a gate electrode being connected with a search line among a plurality of transistors constituting the comparison circuit CP is connected with a match line HMLr being precharged with a high voltage. A match line decision circuit MDr is arranged in a match line LMLr being precharged with a low voltage and a comparison signal voltage generated in that match line is discriminated depending on the comparison results of information. With such arrangement and operation of a memory array, comparison operation can be carried out at high speed with low power while avoiding the effect of search line driving noise in a pair of match lines. A low power content addressable memory capable of performing search operation at high speed can thereby be realized.
