masked write transfer (MWT)

A write transfer in which the transfer of new data from the serial register into the memory array is controlled by a write mask that is supplied on the DG(n) terminals. This mask allows the selective writing of new data into one or more of the data bit planes of the storage array corresponding to the data bits of the parallel array. In a normal implementation, a high M value enables the writing of new data while a low M inhibits the writing and leaves the existing data unchanged. A new mask value must be supplied for each masked write cycle.

References: 

JESD21-C, 1/97