A magnetic resistance memory includes an identity determining unit that
compares, bit by bit, first data stored in an address specified by a
write request with second data to be written to the address, and that
determines whether bit-by-bit values of the first data and the second
data are identical; and a writing control unit that halts, when a bit of
the second data is identical with a corresponding bit of the first data,
writing of the bit of the second data.