A display data RAM has a storage area and a pre-charging circuit section. The storage area has LCD bit lines to be used for reading out display data stored in memory cells. The pre-charging circuit section has pre-charging lines and preset lines. Pieces of information of a particular order bit among the display data stored in the memory cells can be read out by supplying a potential to a selected one of the pre-charging lines. As a result, the power consumption of the display driver can be reduced.