  An ultra fast bit addressing scheme for magnetic random access memories
(MRAM) in a crossed wire geometry is proposed. In the addressing scheme a word
of cells is programmed simultaneously by sub nanosecond field pulses making use
of the magnetization precession of the free layer. Single spin simulations of
the free layer dynamics show that the pulse parameters for programming an
arbitrary word of the array can be chosen such that the magnetization of the
cells to be written performs either a half or a full precessional turn during
application of the programming pulse depending on the initial and final
magnetization orientation of the addressed cells. Such bit addressing scheme
leads to a suppression of the magnetization ringing in all cells of the memory
array thereby allowing ultra high MRAM write clock rates above 1 GHz.
