PURPOSE: To provide a semiconductor memory device suitable for realizing a superimpose function in a device where miniaturization and light weight are of importance.
CONSTITUTION: This device is provided with a register 11 for mask address capable of holding address information for designating one part of a memory cell array 16 as a information storage area for superimpose and an address comparator 13 for comparing the address inputted through an address controller 12 with the held information in the register 11 for mask address and further, this device is provided with a gate 19 for inhibiting write into the information storage area for superimpose based on the compared result MPX of the address comparator in the case of writing data for display. Thus, the superimpose function is provided by a frame memory itself.
SAIE YASUHIKO
KIKUCHI TAKASHI
YOKOBE CHIHOKO
NISHIMOTO KENJI
MATSUBA SHINICHI
HITACHI VLSI ENG
Next Patent: 電線接続処理ロボット装置における芯線処理装置