NON-VOLATILE SEMICONDUCTOR MEMORY

摘要

PURPOSE:To surely write information in a non-volatile memory cell transistor and to shorten the time for writing information. CONSTITUTION:A drain of memory cell transistor Ma1 is connected to a sub-bit line BLsa1 of an EEPROM. The sub-bit line is connected to a main bit line BLa1 through a drain/source of a selection transistor Tsa1. Equivalent capacity Co of the subbit line is previously charged to a potential of the main bit line by temporary ON operation of the selection transistor. A potential of the sub-bit line previously charged is inclined to reduce owing to existence of a leakage current component equivalent resistance Ro, but reduction of a potential of the sub-bit line is prevented by intermittently turning on the selection transistor with a pulse and replenishing electric charges from the main bit line to the sub-bit line.