Nonvolatile semiconductor memory device with electrically selectable, erasable and programmable function

摘要

A nonvolatile semiconductor memory device has a memory cell array including a MOS FET with a floating gate, first and second control gates and a program electrode; column and row decoders for selecting a specific memory cell; a program control circuit for programming data on the floating gate; and a timing circuit for providing operation timings of the column and row decoders and the program control circuit. The timing circuit sets up a program inhibit period ranging over time point at which a selected memory cell is to be erased and programmed. In the program inhibit period, one of the first and second control gates of each of the memory cells is at a high potential, while the other control gate is at low potential.