A method for operating a controller may include storing a pseudo noise (PN) sequence provided from a PN sequence generator in an i-th area of a seed table and cyclically shifting the PN sequence from the i-th area to an (i+1)-th area in the table to form the table. The table may include row and column areas. A method for operating a controller may include receiving a sequence from a sequence generator, splitting the sequence into seed units, storing split sequences in a j-th area of the seed table, and forming the table including the seed units corresponding to the split sequences stored in the j-th area. A method for operating a controller may include storing a sequence provided from a sequence generator in a seed table that includes a plurality of areas and cyclically shifting the sequence in the table until a seed is formed in each area.