Magnetic memory cells include a changeable magnetic region with a magnetic
axis along which two directions of magnetization can be imposed, thereby
providing two respective states into which the cells are changeable
according to electrical and resultant magnetic stimuli applied thereto.
Asymmetry in the magnetic stimuli applied to the cell while writing a
state therein is disclosed to provide a predictable magnetization pattern
evolution from the first direction to the second direction. Physical
asymmetry in the layout and/or magnetization of the cell is also disclosed
which provides the predictable pattern evolution. These principles can be
applied to magnetic random access memory (MRAM) arrays which employ
magnetic tunnel junction (MTJ) cells at the intersections of bitlines and
wordlines which supply the electrical and resultant magnetic stimuli to
write the cells therein.