a signature circuit stores signature information indicative of one of a plurality of device functions of a non - volatile memory device which includes first memory cells which are respectively coupled to one of a plurality of word lines and to one of a plurality of bit lines . the signature circuit includes second memory cells which are respectively connected to the bit lines which are grouped into a plurality of blocks , at least one predetermined word line which is provided exclusively for the second memory cells and is connected to each of the memory cells , and a selecting circuit coupled to the bit lines for selecting one of the blocks . the second memory cells in each of the blocks store one kind of signature information , so that a number of blocks is equal to a number of kinds of signature information that can be stored in the signature circuit .