1. A memory device including an associative memory for the storage of data belonging to a plurality of classes, said associative memory comprising a plurality of memory locations aligned along a first and a second direction for the storage of the data along lines of memory extending along said first direction, each line of memory of said associative memory comprising a plurality of groups of memory locations, each group of locations of a line storing a respective datum, wherein groups of memory locations adjacent in said first direction and belonging to one and the same line store data belonging to different classes, and groups of memory locations adjacent in said second direction and belonging to different lines store data belonging to one and the same class.