input/output data mask (DQM)

A control signal, used primarily on SDRAMs, that acts as a mask for reading and writing functions. In some instances, the DQM term includes a prefix "U" or "L" indicating upper or lower byte control. In devices where more than two data bit groupings have a data mask applied, an "x" is applied, where "x" takes the values of a, b, c, etc.

References